Patchwork tcp: fix ICMP-RTO war

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Submitter Ilpo Järvinen
Date Jan. 23, 2010, 10:34 p.m.
Message ID <alpine.DEB.2.00.1001240007530.16552@melkinpaasi.cs.helsinki.fi>
Download mbox | patch
Permalink /patch/43585/
State Superseded
Delegated to: David Miller
Headers show

Comments

Ilpo Järvinen - Jan. 23, 2010, 10:34 p.m.
Restored Damian cc, please keep them.

On Sat, 23 Jan 2010, Denys Fedoryshchenko wrote:
> On Tuesday 19 January 2010 13:17:51 you wrote:
> > On Tue, 19 Jan 2010, Denys Fedoryshchenko wrote:
> > > On Tuesday 19 January 2010 11:10:12 you wrote:
> > > > Hi,
> > > > thank you for testing. So srtt and rttvar is zero in any of those
> > > > cases. Ilpo, it is a bug in tcp_rtt_estimator then, I suppose?
> > > >
> > > > There is also a code comment in tcp_input.c, saying:
> > > > > * NOTE: clamping at TCP_RTO_MIN is not required, current algo
> > > > > * guarantees that rto is higher.
> > > >
> > > > So we either fix tcp_rtt_estimator or simply clamp at TCP_RTO_MIN?
> > > >
> > > > Damian
> > > >
> > > > > On Monday 11 January 2010 15:02:34 you wrote:
> > > > >> On Sat, 26 Dec 2009, Denys Fedoryshchenko wrote:
> > > > >>> Few more dumps. I notice:
> > > > >>> 1)Ack always equal 1
> > > > >>> 2)It is usually first segment of data sent (?)
> > > > >>>
> > > > >>> Maybe some value not initialised properly?
> > > > >>
> > > > >> Can you see if the RTO lower bound is violated (I added some
> > > > >> printing of vars there too already now if it turns out to be
> > > > >> something):
> > > > >>
> > > > >> diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
> > > > >> index 65b8ebf..d84469f 100644
> > > > >> --- a/net/ipv4/tcp_ipv4.c
> > > > >> +++ b/net/ipv4/tcp_ipv4.c
> > >
> > > As i see in code it is rounding RTO to minimum value.
> > > It fixes my problem seems.
> > >
> > > Btw just a bit about my environment - wireless networks (sometimes
> > > lossy!) with low speed (128-512Kbps) customers working over pppoe. Maybe
> > > it will give a tip why rtt value is too low.
> > 
> > What I find most strange in it is the fact that when it triggers for the
> > first time, the srtt and mdev are zero, not some value in between 0 and
> > 200ms. Therefore I suspect that this case might be something that we've
> > overlooked where srtt/mdev are not valid at all.
> > 
> > Maybe the patch below helps...
> > 
> Seems after this patch (and debug patch with warnings) my dmesg is clean.

Cool, thanks for testing.

Dave, please send into stable too (besides net-2.6). If we want less strict 
state check we can continue playing with that in net-next, IMHO.
Denys Fedoryshchenko - Jan. 23, 2010, 10:45 p.m.
> 
> Cool, thanks for testing.
> 
> Dave, please send into stable too (besides net-2.6). If we want less strict
> state check we can continue playing with that in net-next, IMHO.
> 
Maybe better to wait. Sad news, got messages after while (before they was 
appearing  almost immediately on such load).

Here it is
[ 1253.821745] rto: 26496 (58 >> 3 + 200, 7) time: 953821 sent: 953283 pen: 1 
1006275 rem: 25958                                                                                 
[ 1278.791976] rto: 75264 (398 >> 3 + 245, 8) time: 978791 sent: 977749 pen: 1 
1097749 rem: 74222                                                                                
[ 1299.537823] lower bound violation: 0                                                                                                                                          
[ 1299.537846] rto: 200 (0 >> 3 + 0, 1) time: 999537 sent: 997699 pen: 1 
1009699 rem: 0                                                                                          
[ 1324.022158] rto: 11072 (2512 >> 3 + 1070, 3) time: 1024022 sent: 1023672 
pen: 1 1045816 rem: 10722                                                                            
[ 1333.112517] rto: 52992 (58 >> 3 + 200, 8) time: 1033112 sent: 1032771 pen: 
1 1138755 rem: 52651                                                                               
[ 1336.152839] rto: 11072 (2512 >> 3 + 1070, 3) time: 1036152 sent: 1034744 
pen: 1 1056888 rem: 9664                                                                             
[ 1426.219799] lower bound violation: 0                                                                                                                                          
[ 1426.219858] rto: 200 (0 >> 3 + 0, 1) time: 1126219 sent: 1125040 pen: 1 
1137040 rem: 0                                                                                        
[ 1429.235911] lower bound violation: 0                                                                                                                                          
[ 1429.235964] rto: 200 (0 >> 3 + 0, 4) time: 1129235 sent: 1129019 pen: 1 
1132219 rem: 0                                                                                        
[ 1432.279829] lower bound violation: 0                                                                                                                                          
[ 1432.279887] rto: 200 (0 >> 3 + 0, 7) time: 1132279 sent: 1132036 pen: 1 
1135236 rem: 0                                                                                        
[ 1435.311008] lower bound violation: 0                                                                                                                                          
[ 1435.311068] rto: 200 (0 >> 3 + 0, 10) time: 1135311 sent: 1135079 pen: 1 
1138279 rem: 0                                                                                       
[ 1479.029269] lower bound violation: 0                                                                                                                                          
[ 1479.029323] rto: 200 (0 >> 3 + 0, 9) time: 1179029 sent: 1174129 pen: 1 
1294129 rem: 0                                                                                        
[ 1483.851712] lower bound violation: 0                                                                                                                                          
[ 1483.851773] rto: 200 (0 >> 3 + 0, 12) time: 1183851 sent: 1181829 pen: 1 
1185029 rem: 0                                                                                       
[ 1483.851878] lower bound violation: 0                                                                                                                                          
[ 1483.851926] rto: 200 (0 >> 3 + 0, 12) time: 1183851 sent: 1183851 pen: 1 
1184251 rem: 200                                                                                     
[ 1483.852034] lower bound violation: 0                                                                                                                                          
[ 1483.852082] rto: 200 (0 >> 3 + 0, 11) time: 1183852 sent: 1183851 pen: 1 
1184052 rem: 199                                                                                     
[ 1486.934283] lower bound violation: 0                                                                                                                                          
[ 1486.934339] rto: 200 (0 >> 3 + 0, 14) time: 1186934 sent: 1186851 pen: 1 
1190051 rem: 117                                                                                     
[ 1486.934500] lower bound violation: 0                                                                                                                                          
[ 1486.934554] rto: 200 (0 >> 3 + 0, 13) time: 1186934 sent: 1186851 pen: 1 
1187051 rem: 117                                                                                     
[ 1490.170941] lower bound violation: 0                                                                                                                                          
[ 1490.171000] rto: 200 (0 >> 3 + 0, 16) time: 1190170 sent: 1189851 pen: 1 
1193051 rem: 0                                                                                       
[ 1490.171126] lower bound violation: 0                                                                                                                                          
[ 1490.171189] rto: 200 (0 >> 3 + 0, 16) time: 1190171 sent: 1190171 pen: 1 
1190571 rem: 200                                                                                     
[ 1490.171312] lower bound violation: 0                                                                                                                                          
[ 1490.171361] rto: 200 (0 >> 3 + 0, 15) time: 1190171 sent: 1190171 pen: 1 
1190371 rem: 200                                                                                     
[ 1494.052047] lower bound violation: 0                                                                                                                                          
[ 1494.052105] rto: 200 (0 >> 3 + 0, 18) time: 1194052 sent: 1193171 pen: 1 
1196371 rem: 0                                                                                       
[ 1494.052704] lower bound violation: 0                                                                                                                                          
[ 1494.052760] rto: 200 (0 >> 3 + 0, 18) time: 1194052 sent: 1194052 pen: 1 
1194452 rem: 200                                                                                     
[ 1497.678945] lower bound violation: 0                                                                                                                                          
[ 1497.679004] rto: 200 (0 >> 3 + 0, 21) time: 1197678 sent: 1197052 pen: 1 
1200252 rem: 0                                                                                       
[ 1497.679205] lower bound violation: 0                                                                                                                                          
[ 1497.679255] rto: 200 (0 >> 3 + 0, 21) time: 1197679 sent: 1197679 pen: 1 
1198079 rem: 200                                                                                     
[ 1497.679356] rto: 120000 (18111 >> 3 + 2633, 7) time: 1197679 sent: 1195423 
pen: 1 1315423 rem: 117744                                                                         
[ 1501.113733] lower bound violation: 0                                                                                                                                          
[ 1501.113786] rto: 200 (0 >> 3 + 0, 24) time: 1201113 sent: 1200679 pen: 1 
1203879 rem: 0                                                                                       
[ 1501.116064] rto: 120000 (17704 >> 3 + 4426, 8) time: 1201116 sent: 1198638 
pen: 1 1318638 rem: 117522                                                                         
[ 1501.116168] lower bound violation: 0                                                                                                                                          
[ 1501.116216] rto: 200 (0 >> 3 + 0, 24) time: 1201116 sent: 1201113 pen: 1 
1201513 rem: 197                                                                                     
[ 1504.165893] lower bound violation: 0                                                                                                                                          
[ 1504.165953] rto: 200 (0 >> 3 + 0, 27) time: 1204165 sent: 1204113 pen: 1 
1207313 rem: 148                                                                                     
[ 1504.168090] lower bound violation: 0                                                                                                                                          
[ 1504.168151] rto: 200 (0 >> 3 + 0, 26) time: 1204168 sent: 1204113 pen: 1 
1204313 rem: 145                                                                                     
[ 1504.168272] lower bound violation: 0                                                                                                                                          
[ 1504.168327] rto: 200 (0 >> 3 + 0, 25) time: 1204168 sent: 1204113 pen: 1 
1204313 rem: 145                                                                                     
[ 1507.280037] lower bound violation: 0                                                                                                                                          
[ 1507.280096] rto: 200 (0 >> 3 + 0, 28) time: 1207280 sent: 1207113 pen: 1 
1210313 rem: 33                                                                                      
[ 1507.280207] lower bound violation: 0                                                                                                                                          
[ 1507.280255] rto: 200 (0 >> 3 + 0, 27) time: 1207280 sent: 1207113 pen: 1 
1207313 rem: 33                                                                                      
[ 1510.974508] lower bound violation: 0                                                                                                                                          
[ 1510.974574] rto: 200 (0 >> 3 + 0, 30) time: 1210974 sent: 1210113 pen: 1 
1213313 rem: 0                                                                                       
[ 1510.974716] lower bound violation: 0                                                                                                                                          
[ 1510.974766] rto: 200 (0 >> 3 + 0, 30) time: 1210974 sent: 1210974 pen: 1 
1211374 rem: 200                                                                                     
[ 1514.436146] lower bound violation: 0                                                                                                                                          
[ 1514.436214] rto: 200 (0 >> 3 + 0, 33) time: 1214436 sent: 1213974 pen: 1 
1217174 rem: 0                                                                                       
[ 1514.436329] lower bound violation: 0                                                                                                                                          
[ 1514.436378] rto: 200 (0 >> 3 + 0, 33) time: 1214436 sent: 1214436 pen: 1 
1214836 rem: 200                                                                                     
[ 1514.436477] lower bound violation: 0                                                                                                                                          
[ 1514.436525] rto: 200 (0 >> 3 + 0, 32) time: 1214436 sent: 1214436 pen: 1 
1214636 rem: 200                                                                                     
[ 1517.516478] lower bound violation: 0                                                                                                                                          
[ 1517.516537] rto: 200 (0 >> 3 + 0, 35) time: 1217516 sent: 1217436 pen: 1 
1220636 rem: 120                                                                                     
[ 1517.520665] lower bound violation: 0                                                                                                                                          
[ 1517.520724] rto: 200 (0 >> 3 + 0, 34) time: 1217520 sent: 1217436 pen: 1 
1217636 rem: 116                                                                                     
[ 1517.520865] lower bound violation: 0                                                                                                                                          
[ 1517.520919] rto: 200 (0 >> 3 + 0, 33) time: 1217520 sent: 1217436 pen: 1 
1217636 rem: 116                                                                                     
[ 1520.579941] lower bound violation: 0                                                                                                                                          
[ 1520.580000] rto: 200 (0 >> 3 + 0, 36) time: 1220579 sent: 1220436 pen: 1 
1223636 rem: 57                                                                                      
[ 1520.580111] lower bound violation: 0                                                                                                                                          
[ 1520.580165] rto: 200 (0 >> 3 + 0, 35) time: 1220580 sent: 1220436 pen: 1 
1220637 rem: 56                                                                                      
[ 1520.580686] lower bound violation: 0                                                                                                                                          
[ 1520.580744] rto: 200 (0 >> 3 + 0, 34) time: 1220580 sent: 1220436 pen: 1 
1220636 rem: 56                                                                                      
[ 1523.693352] lower bound violation: 0                                                                                                                                          
[ 1523.693412] rto: 200 (0 >> 3 + 0, 37) time: 1223693 sent: 1223436 pen: 1 
1226636 rem: 0                                                                                       
[ 1523.693538] lower bound violation: 0                                                                                                                                          
[ 1523.693588] rto: 200 (0 >> 3 + 0, 37) time: 1223693 sent: 1223693 pen: 1 
1224093 rem: 200                                                                                     
[ 1523.693686] lower bound violation: 0                                                                                                                                          
[ 1523.693735] rto: 200 (0 >> 3 + 0, 36) time: 1223693 sent: 1223693 pen: 1 
1223893 rem: 200                                                                                     
[ 1526.737059] lower bound violation: 0                                                                                                                                          
[ 1526.737125] rto: 200 (0 >> 3 + 0, 39) time: 1226737 sent: 1226693 pen: 1 
1229893 rem: 156                                                                                     
[ 1526.737271] lower bound violation: 0                                                                                                                                          
[ 1526.737323] rto: 200 (0 >> 3 + 0, 38) time: 1226737 sent: 1226693 pen: 1 
1226893 rem: 156                                                                                     
[ 1526.737557] lower bound violation: 0                                                                                                                                          
[ 1526.737607] rto: 200 (0 >> 3 + 0, 37) time: 1226737 sent: 1226693 pen: 1 
1226893 rem: 156                                                                                     
[ 1529.979070] lower bound violation: 0                                                                                                                                          
[ 1529.979130] rto: 200 (0 >> 3 + 0, 40) time: 1229979 sent: 1229693 pen: 1 
1232893 rem: 0                                                                                       
[ 1529.979249] lower bound violation: 0                                                                                                                                          
[ 1529.979304] rto: 200 (0 >> 3 + 0, 40) time: 1229979 sent: 1229979 pen: 1 
1230379 rem: 200                                                                                     
[ 1529.979412] lower bound violation: 0                                                                                                                                          
[ 1529.979461] rto: 200 (0 >> 3 + 0, 39) time: 1229979 sent: 1229979 pen: 1 
1230179 rem: 200                                                                                     
[ 1533.211875] lower bound violation: 0                                                                                                                                          
[ 1533.211934] rto: 200 (0 >> 3 + 0, 42) time: 1233211 sent: 1232979 pen: 1 
1236179 rem: 0                                                                                       
[ 1533.212049] lower bound violation: 0                                                                                                                                          
[ 1533.212098] rto: 200 (0 >> 3 + 0, 42) time: 1233211 sent: 1233211 pen: 1 
1233611 rem: 200                                                                                     
[ 1533.212203] lower bound violation: 0                                                                                                                                          
[ 1533.212259] rto: 200 (0 >> 3 + 0, 41) time: 1233212 sent: 1233211 pen: 1 
1233412 rem: 199                                                                                     
[ 1536.287558] lower bound violation: 0                                                                                                                                          
[ 1536.287611] rto: 200 (0 >> 3 + 0, 44) time: 1236287 sent: 1236211 pen: 1 
1239411 rem: 124                                                                                     
[ 1536.287712] lower bound violation: 0                                                                                                                                          
[ 1536.287760] rto: 200 (0 >> 3 + 0, 43) time: 1236287 sent: 1236211 pen: 1 
1236411 rem: 124                                                                                     
[ 1536.291704] lower bound violation: 0                                                                                                                                          
[ 1536.291767] rto: 200 (0 >> 3 + 0, 42) time: 1236291 sent: 1236211 pen: 1 
1236411 rem: 120                                                                                     
[ 1539.530596] lower bound violation: 0                                                                                                                                          
[ 1539.530657] rto: 200 (0 >> 3 + 0, 45) time: 1239530 sent: 1239211 pen: 1 
1242411 rem: 0                                                                                       
[ 1539.530804] lower bound violation: 0                                                                                                                                          
[ 1539.530862] rto: 200 (0 >> 3 + 0, 45) time: 1239530 sent: 1239530 pen: 1 
1239930 rem: 200                                                                                     
[ 1544.020855] lower bound violation: 0                                                                                                                                          
[ 1544.020916] rto: 200 (0 >> 3 + 0, 48) time: 1244020 sent: 1242530 pen: 1 
1245730 rem: 0                                                                                       
[ 1544.021022] lower bound violation: 0                                                                                                                                          
[ 1544.021071] rto: 200 (0 >> 3 + 0, 48) time: 1244021 sent: 1244020 pen: 1 
1244421 rem: 199                                                                                     
[ 1544.021186] lower bound violation: 0                                                                                                                                          
[ 1544.021243] rto: 200 (0 >> 3 + 0, 47) time: 1244021 sent: 1244020 pen: 1 
1244220 rem: 199                                                                                     
[ 1547.214143] lower bound violation: 0                                                                                                                                          
[ 1547.214212] rto: 200 (0 >> 3 + 0, 50) time: 1247214 sent: 1247020 pen: 1 
1250220 rem: 6                                                                                       
[ 1547.214330] lower bound violation: 0                                                                                                                                          
[ 1547.214388] rto: 200 (0 >> 3 + 0, 49) time: 1247214 sent: 1247020 pen: 1 
1247220 rem: 6                                                                                       
[ 1547.215213] lower bound violation: 0                                                                                                                                          
[ 1547.215269] rto: 200 (0 >> 3 + 0, 48) time: 1247215 sent: 1247020 pen: 1 
1247221 rem: 5                                                                                       
[ 1551.820989] lower bound violation: 0                                                                                                                                          
[ 1551.821059] rto: 200 (0 >> 3 + 0, 51) time: 1251821 sent: 1250020 pen: 1 
1253220 rem: 0                                                                                       
[ 1551.821211] lower bound violation: 0                                                                                                                                          
[ 1551.821265] rto: 200 (0 >> 3 + 0, 51) time: 1251821 sent: 1251821 pen: 1 
1252221 rem: 200                                                                                     
[ 1551.824378] lower bound violation: 0                                                                                                                                          
[ 1551.824437] rto: 200 (0 >> 3 + 0, 50) time: 1251824 sent: 1251821 pen: 1 
1252021 rem: 197                                                                                     
[ 1556.833941] lower bound violation: 0                                                                                                                                          
[ 1556.834001] rto: 200 (0 >> 3 + 0, 53) time: 1256833 sent: 1254821 pen: 1 
1258021 rem: 0                                                                                       
[ 1556.834120] lower bound violation: 0                                                                                                                                          
[ 1556.834168] rto: 200 (0 >> 3 + 0, 53) time: 1256834 sent: 1256834 pen: 1 
1257234 rem: 200                                                                                     
[ 1556.834280] lower bound violation: 0                                                                                                                                          
[ 1556.834335] rto: 200 (0 >> 3 + 0, 52) time: 1256834 sent: 1256834 pen: 1 
1257034 rem: 200                                                                                     
[ 1559.862274] lower bound violation: 0                                                                                                                                          
[ 1559.862332] rto: 200 (0 >> 3 + 0, 55) time: 1259862 sent: 1259834 pen: 1 
1263034 rem: 172                                                                                     
[ 1559.862439] lower bound violation: 0                                                                                                                                          
[ 1559.862488] rto: 200 (0 >> 3 + 0, 54) time: 1259862 sent: 1259834 pen: 1 
1260034 rem: 172                                                                                     
[ 1559.862599] lower bound violation: 0                                                                                                                                          
[ 1559.862653] rto: 200 (0 >> 3 + 0, 53) time: 1259862 sent: 1259834 pen: 1 
1260034 rem: 172                                                                                     
[ 1563.299323] lower bound violation: 0                                                                                                                                          
[ 1563.299392] rto: 200 (0 >> 3 + 0, 56) time: 1263299 sent: 1262834 pen: 1 
1266034 rem: 0                                                                                       
[ 1563.299544] lower bound violation: 0                                                                                                                                          
[ 1563.299593] rto: 200 (0 >> 3 + 0, 56) time: 1263299 sent: 1263299 pen: 1 
1263699 rem: 200                                                                                     
[ 1563.299692] lower bound violation: 0                                                                                                                                          
[ 1563.299740] rto: 200 (0 >> 3 + 0, 55) time: 1263299 sent: 1263299 pen: 1 
1263499 rem: 200                                                                                     
[ 1566.413518] lower bound violation: 0                                                                                                                                          
[ 1566.413571] rto: 200 (0 >> 3 + 0, 58) time: 1266413 sent: 1266299 pen: 1 
1269499 rem: 86                                                                                      
[ 1566.413689] lower bound violation: 0                                                                                                                                          
[ 1566.413745] rto: 200 (0 >> 3 + 0, 57) time: 1266413 sent: 1266299 pen: 1 
1266499 rem: 86                                                                                      
[ 1566.413844] lower bound violation: 0                                                                                                                                          
[ 1566.413892] rto: 200 (0 >> 3 + 0, 56) time: 1266413 sent: 1266299 pen: 1 
1266499 rem: 86                                                                                      
[ 1569.443770] lower bound violation: 0                                                                                                                                          
[ 1569.443829] rto: 200 (0 >> 3 + 0, 59) time: 1269443 sent: 1269299 pen: 1 
1272499 rem: 56                                                                                      
[ 1569.444010] lower bound violation: 0                                                                                                                                          
[ 1569.444064] rto: 200 (0 >> 3 + 0, 58) time: 1269444 sent: 1269299 pen: 1 
1269499 rem: 55                                                                                      
[ 1569.451656] lower bound violation: 0                                                                                                                                          
[ 1569.451714] rto: 200 (0 >> 3 + 0, 57) time: 1269451 sent: 1269299 pen: 1 
1269499 rem: 48                                                                                      
[ 1573.751979] lower bound violation: 0                                                                                                                                          
[ 1573.752048] rto: 200 (0 >> 3 + 0, 60) time: 1273752 sent: 1272299 pen: 1 
1275499 rem: 0                                                                                       
[ 1573.752172] lower bound violation: 0                                                                                                                                          
[ 1573.752229] rto: 200 (0 >> 3 + 0, 60) time: 1273752 sent: 1273752 pen: 1 
1274152 rem: 200                                                                                     
[ 1573.752343] lower bound violation: 0                                                                                                                                          
[ 1573.752392] rto: 200 (0 >> 3 + 0, 59) time: 1273752 sent: 1273752 pen: 1 
1273952 rem: 200                                                                                     
[ 1579.041006] lower bound violation: 0                                                                                                                                          
[ 1579.041068] rto: 200 (0 >> 3 + 0, 62) time: 1279041 sent: 1276752 pen: 1 
1279952 rem: 0                                                                                       
[ 1579.041177] lower bound violation: 0                                                                                                                                          
[ 1579.041226] rto: 200 (0 >> 3 + 0, 62) time: 1279041 sent: 1279041 pen: 1 
1279441 rem: 200                                                                                     
[ 1579.041325] lower bound violation: 0                                                                                                                                          
[ 1579.041373] rto: 200 (0 >> 3 + 0, 61) time: 1279041 sent: 1279041 pen: 1 
1279241 rem: 200                                                                                     
[ 1584.072083] lower bound violation: 0                                                                                                                                          
[ 1584.072149] rto: 200 (0 >> 3 + 0, 64) time: 1284072 sent: 1282041 pen: 1 
1285241 rem: 0                                                                                       
[ 1587.094402] lower bound violation: 0                                                                                                                                          
[ 1587.094461] rto: 200 (0 >> 3 + 0, 67) time: 1287094 sent: 1286872 pen: 1 
1290072 rem: 0                                                                                       
[ 1587.095380] lower bound violation: 0                                                                                                                                          
[ 1587.095442] rto: 200 (0 >> 3 + 0, 67) time: 1287095 sent: 1287094 pen: 1 
1287494 rem: 199                                                                                     
[ 1590.118759] lower bound violation: 0                                                                                                                                          
[ 1590.118818] rto: 200 (0 >> 3 + 0, 70) time: 1290118 sent: 1290094 pen: 1 
1293294 rem: 176                                                                                     
[ 1590.118931] lower bound violation: 0                                                                                                                                          
[ 1590.118979] rto: 200 (0 >> 3 + 0, 69) time: 1290118 sent: 1290094 pen: 1 
1290294 rem: 176                                                                                     
[ 1590.119085] lower bound violation: 0                                                                                                                                          
[ 1590.119142] rto: 200 (0 >> 3 + 0, 68) time: 1290119 sent: 1290094 pen: 1 
1290295 rem: 175                                                                                     
[ 1593.342497] lower bound violation: 0                                                                                                                                          
[ 1593.342556] rto: 200 (0 >> 3 + 0, 71) time: 1293342 sent: 1293094 pen: 1 
1296294 rem: 0                                                                                       
[ 1593.342675] lower bound violation: 0                                                                                                                                          
[ 1593.342723] rto: 200 (0 >> 3 + 0, 71) time: 1293342 sent: 1293342 pen: 1 
1293742 rem: 200                                                                                     
[ 1593.342822] lower bound violation: 0                                                                                                                                          
[ 1593.342870] rto: 200 (0 >> 3 + 0, 70) time: 1293342 sent: 1293342 pen: 1 
1293542 rem: 200                                                                                     
[ 1597.517273] lower bound violation: 0                                                                                                                                          
[ 1597.517326] rto: 200 (0 >> 3 + 0, 73) time: 1297517 sent: 1296342 pen: 1 
1299542 rem: 0                                                                                       
[ 1597.517433] lower bound violation: 0                                                                                                                                          
[ 1597.517481] rto: 200 (0 >> 3 + 0, 73) time: 1297517 sent: 1297517 pen: 1 
1297917 rem: 200                                                                                     
[ 1597.517579] lower bound violation: 0                                                                                                                                          
[ 1597.517627] rto: 200 (0 >> 3 + 0, 72) time: 1297517 sent: 1297517 pen: 1 
1297717 rem: 200                                                                                     
[ 1600.931564] lower bound violation: 0                                                                                                                                          
[ 1600.931625] rto: 200 (0 >> 3 + 0, 75) time: 1300931 sent: 1300517 pen: 1 
1303717 rem: 0                                                                                       
[ 1600.931743] lower bound violation: 0                                                                                                                                          
[ 1600.931792] rto: 200 (0 >> 3 + 0, 75) time: 1300931 sent: 1300931 pen: 1 
1301331 rem: 200                                                                                     
[ 1600.931903] lower bound violation: 0                                                                                                                                          
[ 1600.931954] rto: 200 (0 >> 3 + 0, 74) time: 1300931 sent: 1300931 pen: 1 
1301131 rem: 200                                                                                     
[ 1603.939116] lower bound violation: 0                                                                                                                                          
[ 1603.939176] rto: 200 (0 >> 3 + 0, 77) time: 1303939 sent: 1303932 pen: 1 
1307132 rem: 193                                                                                     
[ 1603.939289] lower bound violation: 0                                                                                                                                          
[ 1603.939337] rto: 200 (0 >> 3 + 0, 76) time: 1303939 sent: 1303932 pen: 1 
1304132 rem: 193                                                                                     
[ 1603.939436] lower bound violation: 0                                                                                                                                          
[ 1603.939484] rto: 200 (0 >> 3 + 0, 75) time: 1303939 sent: 1303932 pen: 1 
1304132 rem: 193                                                                                     
[ 1607.414745] lower bound violation: 0                                                                                                                                          
[ 1607.414808] rto: 200 (0 >> 3 + 0, 78) time: 1307414 sent: 1306932 pen: 1 
1310132 rem: 0                                                                                       
[ 1607.414956] lower bound violation: 0                                                                                                                                          
[ 1607.415015] rto: 200 (0 >> 3 + 0, 78) time: 1307414 sent: 1307414 pen: 1 
1307814 rem: 200                                                                                     
[ 1610.428738] lower bound violation: 0                                                                                                                                          
[ 1610.428797] rto: 200 (0 >> 3 + 0, 81) time: 1310428 sent: 1310414 pen: 1 
1313614 rem: 186                                                                                     
[ 1610.428909] lower bound violation: 0                                                                                                                                          
[ 1610.428957] rto: 200 (0 >> 3 + 0, 80) time: 1310428 sent: 1310414 pen: 1 
1310614 rem: 186                                                                                     
[ 1610.429061] lower bound violation: 0                                                                                                                                          
[ 1610.429118] rto: 200 (0 >> 3 + 0, 79) time: 1310428 sent: 1310414 pen: 1 
1310614 rem: 186                                                                                     
[ 1613.744633] lower bound violation: 0                                                                                                                                          
[ 1613.744696] rto: 200 (0 >> 3 + 0, 82) time: 1313744 sent: 1313415 pen: 1 
1316615 rem: 0                                                                                       
[ 1613.745417] lower bound violation: 0                                                                                                                                          
[ 1613.745480] rto: 200 (0 >> 3 + 0, 82) time: 1313745 sent: 1313744 pen: 1 
1314144 rem: 199                                                                                     
[ 1617.868468] lower bound violation: 0                                                                                                                                          
[ 1617.868531] rto: 200 (0 >> 3 + 0, 85) time: 1317868 sent: 1316744 pen: 1 
1319944 rem: 0                                                                                       
[ 1617.868657] lower bound violation: 0                                                                                                                                          
[ 1617.868716] rto: 200 (0 >> 3 + 0, 85) time: 1317868 sent: 1317868 pen: 1 
1318268 rem: 200                                                                                     
[ 1617.868831] rto: 120000 (18111 >> 3 + 2633, 7) time: 1317868 sent: 1315423 
pen: 1 1435423 rem: 117555                                                                         
[ 1621.001005] lower bound violation: 0                                                                                                                                          
[ 1621.001064] rto: 200 (0 >> 3 + 0, 88) time: 1321000 sent: 1320868 pen: 1 
1324068 rem: 68                                                                                      
[ 1621.001176] lower bound violation: 0                                                                                                                                          
[ 1621.001225] rto: 200 (0 >> 3 + 0, 87) time: 1321000 sent: 1320868 pen: 1 
1321068 rem: 68                                                                                      
[ 1621.002106] rto: 120000 (17704 >> 3 + 4426, 8) time: 1321002 sent: 1318638 
pen: 1 1438638 rem: 117636                                                                         
[ 1624.776425] lower bound violation: 0                                                                                                                                          
[ 1624.776484] rto: 200 (0 >> 3 + 0, 90) time: 1324776 sent: 1323868 pen: 1 
1327068 rem: 0                                                                                       
[ 1624.776602] lower bound violation: 0                                                                                                                                          
[ 1624.776651] rto: 200 (0 >> 3 + 0, 90) time: 1324776 sent: 1324776 pen: 1 
1325176 rem: 200                                                                                     
[ 1624.776766] lower bound violation: 0                                                                                                                                          
[ 1624.776815] rto: 200 (0 >> 3 + 0, 89) time: 1324776 sent: 1324776 pen: 1 
1324976 rem: 200                                                                                     
[ 1628.635107] lower bound violation: 0                                                                                                                                          
[ 1628.635166] rto: 200 (0 >> 3 + 0, 92) time: 1328635 sent: 1327776 pen: 1 
1330976 rem: 0                                                                                       
[ 1628.635292] lower bound violation: 0                                                                                                                                          
[ 1628.635340] rto: 200 (0 >> 3 + 0, 92) time: 1328635 sent: 1328635 pen: 1 
1329035 rem: 200                                                                                     
[ 1628.636141] lower bound violation: 0                                                                                                                                          
[ 1628.636189] rto: 200 (0 >> 3 + 0, 91) time: 1328636 sent: 1328635 pen: 1 
1328836 rem: 199                                                                                     
[ 1632.229674] lower bound violation: 0                                                                                                                                          
[ 1632.229736] rto: 200 (0 >> 3 + 0, 94) time: 1332229 sent: 1331635 pen: 1 
1334835 rem: 0                                                                                       
[ 1632.231588] lower bound violation: 0                                                                                                                                          
[ 1632.231645] rto: 200 (0 >> 3 + 0, 94) time: 1332231 sent: 1332229 pen: 1 
1332629 rem: 198                                                                                     
[ 1636.335644] lower bound violation: 0                                                                                                                                          
[ 1636.335704] rto: 200 (0 >> 3 + 0, 97) time: 1336335 sent: 1335229 pen: 1 
1338429 rem: 0                                                                                       
[ 1636.335821] lower bound violation: 0                                                                                                                                          
[ 1636.335870] rto: 200 (0 >> 3 + 0, 97) time: 1336335 sent: 1336335 pen: 1 
1336735 rem: 200                                                                                     
[ 1636.335968] lower bound violation: 0                                                                                                                                          
[ 1636.336015] rto: 200 (0 >> 3 + 0, 96) time: 1336335 sent: 1336335 pen: 1 
1336535 rem: 200                                                                                     
[ 1639.557760] lower bound violation: 0                                                                                                                                          
[ 1639.557819] rto: 200 (0 >> 3 + 0, 99) time: 1339557 sent: 1339336 pen: 1 
1342536 rem: 0                                                                                       
[ 1639.557937] lower bound violation: 0                                                                                                                                          
[ 1639.557985] rto: 200 (0 >> 3 + 0, 99) time: 1339557 sent: 1339557 pen: 1 
1339957 rem: 200                                                                                     
[ 1639.558575] lower bound violation: 0                                                                                                                                          
[ 1639.558631] rto: 200 (0 >> 3 + 0, 98) time: 1339558 sent: 1339557 pen: 1 
1339758 rem: 199                                                                                     
[ 1642.786990] lower bound violation: 0                                                                                                                                          
[ 1642.787060] rto: 200 (0 >> 3 + 0, 101) time: 1342787 sent: 1342557 pen: 1 
1345757 rem: 0                                                                                      
[ 1642.787238] lower bound violation: 0                                                                                                                                          
[ 1642.787296] rto: 200 (0 >> 3 + 0, 101) time: 1342787 sent: 1342787 pen: 1 
1343187 rem: 200                                                                                    
[ 1642.787395] lower bound violation: 0                                                                                                                                          
[ 1642.787444] rto: 200 (0 >> 3 + 0, 100) time: 1342787 sent: 1342787 pen: 1 
1342987 rem: 200                                                                                    
[ 1647.154582] lower bound violation: 0                                                                                                                                          
[ 1647.154634] rto: 200 (0 >> 3 + 0, 103) time: 1347154 sent: 1345787 pen: 1 
1348987 rem: 0                                                                                      
[ 1647.154744] lower bound violation: 0                                                                                                                                          
[ 1647.154792] rto: 200 (0 >> 3 + 0, 103) time: 1347154 sent: 1347154 pen: 1 
1347554 rem: 200                                                                                    
[ 1647.154904] lower bound violation: 0                                                                                                                                          
[ 1647.154952] rto: 200 (0 >> 3 + 0, 102) time: 1347154 sent: 1347154 pen: 1 
1347354 rem: 200                                                                                    
[ 1650.574345] lower bound violation: 0                                                                                                                                          
[ 1650.574406] rto: 200 (0 >> 3 + 0, 105) time: 1350574 sent: 1350155 pen: 1 
1353355 rem: 0                                                                                      
[ 1650.574532] lower bound violation: 0                                                                                                                                          
[ 1650.574591] rto: 200 (0 >> 3 + 0, 105) time: 1350574 sent: 1350574 pen: 1 
1350974 rem: 200                                                                                    
[ 1650.574691] lower bound violation: 0                                                                                                                                          
[ 1650.574739] rto: 200 (0 >> 3 + 0, 104) time: 1350574 sent: 1350574 pen: 1 
1350774 rem: 200                                                                                    
[ 1653.629874] lower bound violation: 0                                                                                                                                          
[ 1653.629937] rto: 200 (0 >> 3 + 0, 107) time: 1353629 sent: 1353574 pen: 1 
1356774 rem: 145                                                                                    
[ 1653.630037] lower bound violation: 0                                                                                                                                          
[ 1653.630086] rto: 200 (0 >> 3 + 0, 106) time: 1353629 sent: 1353574 pen: 1 
1353774 rem: 145                                                                                    
[ 1653.630185] lower bound violation: 0                                                                                                                                          
[ 1653.630233] rto: 200 (0 >> 3 + 0, 105) time: 1353629 sent: 1353574 pen: 1 
1353774 rem: 145                                                                                    
[ 1656.859174] lower bound violation: 0                                                                                                                                          
[ 1656.859236] rto: 200 (0 >> 3 + 0, 108) time: 1356859 sent: 1356574 pen: 1 
1359774 rem: 0                                                                                      
[ 1656.860594] lower bound violation: 0                                                                                                                                          
[ 1656.860650] rto: 200 (0 >> 3 + 0, 108) time: 1356860 sent: 1356859 pen: 1 
1357259 rem: 199                                                                                    
[ 1656.860770] lower bound violation: 0                                                                                                                                          
[ 1656.860818] rto: 200 (0 >> 3 + 0, 107) time: 1356860 sent: 1356859 pen: 1 
1357059 rem: 199                                                                                    
[ 1661.395294] lower bound violation: 0                                                                                                                                          
[ 1661.395347] rto: 200 (0 >> 3 + 0, 110) time: 1361395 sent: 1359859 pen: 1 
1363059 rem: 0                                                                                      
[ 1661.395716] lower bound violation: 0                                                                                                                                          
[ 1661.395772] rto: 200 (0 >> 3 + 0, 110) time: 1361395 sent: 1361395 pen: 1 
1361795 rem: 200                                                                                    
[ 1700.995078] rto: 120000 (2636 >> 3 + 542, 8) time: 1400995 sent: 1397985 
pen: 1 1517985 rem: 116990                                                                           
[ 1730.706641] lower bound violation: 0                                                                                                                                          
[ 1730.706700] rto: 200 (0 >> 3 + 0, 7) time: 1430706 sent: 1429991 pen: 1 
1549991 rem: 0                                                                                        
[ 1733.727118] lower bound violation: 0                                                                                                                                          
[ 1733.727186] rto: 200 (0 >> 3 + 0, 10) time: 1433727 sent: 1433506 pen: 1 
1436706 rem: 0                                                                                       
[ 1736.737622] lower bound violation: 0                                                                                                                                          
[ 1736.737674] rto: 200 (0 >> 3 + 0, 13) time: 1436737 sent: 1436527 pen: 1 
1439727 rem: 0                                                                                       
[ 1739.769166] lower bound violation: 0                                                                                                                                          
[ 1739.769219] rto: 200 (0 >> 3 + 0, 16) time: 1439769 sent: 1439537 pen: 1 
1442737 rem: 0                                                                                       
[ 1739.818141] lower bound violation: 0                                                                                                                                          
[ 1739.818197] rto: 200 (0 >> 3 + 0, 16) time: 1439818 sent: 1439769 pen: 1 
1440169 rem: 151                                                                                     
[ 1742.779541] lower bound violation: 0                                                                                                                                          
[ 1742.779610] rto: 200 (0 >> 3 + 0, 19) time: 1442779 sent: 1442769 pen: 1 
1445969 rem: 190                                                                                     
[ 1742.828450] lower bound violation: 0                                                                                                                                          
[ 1742.828509] rto: 200 (0 >> 3 + 0, 18) time: 1442828 sent: 1442769 pen: 1 
1442969 rem: 141                                                                                     
[ 1745.838989] lower bound violation: 0                                                                                                                                          
[ 1745.839059] rto: 200 (0 >> 3 + 0, 21) time: 1445839 sent: 1445769 pen: 1 
1448969 rem: 130                                                                                     
[ 1748.849390] lower bound violation: 0                                                                                                                                          
[ 1748.849450] rto: 200 (0 >> 3 + 0, 24) time: 1448849 sent: 1448769 pen: 1 
1451969 rem: 120                                                                                     
[ 1751.851312] lower bound violation: 0                                                                                                                                          
[ 1751.851371] rto: 200 (0 >> 3 + 0, 27) time: 1451851 sent: 1451769 pen: 1 
1454969 rem: 118                                                                                     
[ 1755.020232] lower bound violation: 0                                                                                                                                          
[ 1755.020294] rto: 200 (0 >> 3 + 0, 30) time: 1455020 sent: 1454769 pen: 1 
1457969 rem: 0                                                                                       
[ 1758.032994] lower bound violation: 0                                                                                                                                          
[ 1758.033065] rto: 200 (0 >> 3 + 0, 33) time: 1458032 sent: 1457820 pen: 1 
1461020 rem: 0                                                                                       
[ 1761.044708] lower bound violation: 0                                                                                                                                          
[ 1761.044766] rto: 200 (0 >> 3 + 0, 36) time: 1461044 sent: 1460833 pen: 1 
1464033 rem: 0                                                                                       
[ 1764.057713] lower bound violation: 0                                                                                                                                          
[ 1764.057773] rto: 200 (0 >> 3 + 0, 39) time: 1464057 sent: 1463844 pen: 1 
1467044 rem: 0                                                                                       
[ 1767.081929] lower bound violation: 0                                                                                                                                          
[ 1767.082002] rto: 200 (0 >> 3 + 0, 42) time: 1467081 sent: 1466857 pen: 1 
1470057 rem: 0                                                                                       
[ 1770.093869] lower bound violation: 0                                                                                                                                          
[ 1770.093928] rto: 200 (0 >> 3 + 0, 45) time: 1470093 sent: 1469882 pen: 1 
1473082 rem: 0                                                                                       
[ 1773.152744] lower bound violation: 0                                                                                                                                          
[ 1773.152796] rto: 200 (0 >> 3 + 0, 48) time: 1473152 sent: 1472893 pen: 1 
1476093 rem: 0                                                                                       
[ 1818.986470] rto: 120000 (2636 >> 3 + 542, 8) time: 1518986 sent: 1517985 
pen: 1 1637985 rem: 118999                                                                           
[ 1939.433063] rto: 120000 (2636 >> 3 + 542, 8) time: 1639432 sent: 1637985 
pen: 1 1757985 rem: 118553                                                                           
[ 2127.032954] lower bound violation: 0                                                                                                                                          
[ 2127.033019] rto: 200 (0 >> 3 + 0, 5) time: 1827033 sent: 1824734 pen: 1 
1944734 rem: 0                                                                                        
[ 2130.198949] lower bound violation: 0                                                                                                                                          
[ 2130.199008] rto: 200 (0 >> 3 + 0, 8) time: 1830198 sent: 1829833 pen: 1 
1833033 rem: 0                                                                                        
[ 2130.199134] lower bound violation: 0                                                                                                                                          
[ 2130.199191] rto: 200 (0 >> 3 + 0, 8) time: 1830199 sent: 1830199 pen: 1 
1830599 rem: 200                                                                                      
[ 2130.199289] lower bound violation: 0                                                                                                                                          
[ 2130.199336] rto: 200 (0 >> 3 + 0, 7) time: 1830199 sent: 1830199 pen: 1 
1830399 rem: 200                                                                                      
[ 2133.313262] lower bound violation: 0                                                                                                                                          
[ 2133.313321] rto: 200 (0 >> 3 + 0, 10) time: 1833313 sent: 1833199 pen: 1 
1836399 rem: 86                                                                                      
[ 2133.313430] lower bound violation: 0                                                                                                                                          
[ 2133.313483] rto: 200 (0 >> 3 + 0, 9) time: 1833313 sent: 1833199 pen: 1 
1833399 rem: 86                                                                                       
[ 2136.355135] lower bound violation: 0                                                                                                                                          
[ 2136.355194] rto: 200 (0 >> 3 + 0, 12) time: 1836355 sent: 1836199 pen: 1 
1839399 rem: 44                                                                                      
[ 2136.355302] lower bound violation: 0                                                                                                                                          
[ 2136.355355] rto: 200 (0 >> 3 + 0, 11) time: 1836355 sent: 1836199 pen: 1 
1836399 rem: 44                                                                                      
[ 2136.355462] lower bound violation: 0                                                                                                                                          
[ 2136.355510] rto: 200 (0 >> 3 + 0, 10) time: 1836355 sent: 1836199 pen: 1 
1836399 rem: 44                                                                                      
[ 2139.336730] lower bound violation: 0                                                                                                                                          
[ 2139.336790] rto: 200 (0 >> 3 + 0, 13) time: 1839336 sent: 1839199 pen: 1 
1842399 rem: 63                                                                                      
[ 2139.336911] lower bound violation: 0                                                                                                                                          
[ 2139.336960] rto: 200 (0 >> 3 + 0, 12) time: 1839336 sent: 1839199 pen: 1 
1839399 rem: 63                                                                                      
[ 2142.603552] lower bound violation: 0                                                                                                                                          
[ 2142.603612] rto: 200 (0 >> 3 + 0, 15) time: 1842603 sent: 1842200 pen: 1 
1845400 rem: 0                                                                                       
[ 2142.603729] lower bound violation: 0                                                                                                                                          
[ 2142.603777] rto: 200 (0 >> 3 + 0, 15) time: 1842603 sent: 1842603 pen: 1 
1843003 rem: 200                                                                                     
[ 2145.821472] lower bound violation: 0                                                                                                                                          
[ 2145.821533] rto: 200 (0 >> 3 + 0, 18) time: 1845821 sent: 1845603 pen: 1 
1848803 rem: 0                                                                                       
[ 2145.821638] lower bound violation: 0                                                                                                                                          
[ 2145.821687] rto: 200 (0 >> 3 + 0, 18) time: 1845821 sent: 1845821 pen: 1 
1846221 rem: 200                                                                                     
[ 2149.113311] lower bound violation: 0                                                                                                                                          
[ 2149.113371] rto: 200 (0 >> 3 + 0, 21) time: 1849113 sent: 1848822 pen: 1 
1852022 rem: 0                                                                                       
[ 2149.124655] lower bound violation: 0                                                                                                                                          
[ 2149.124717] rto: 200 (0 >> 3 + 0, 21) time: 1849124 sent: 1849113 pen: 1 
1849513 rem: 189                                                                                     
[ 2152.214537] lower bound violation: 0                                                                                                                                          
[ 2152.214596] rto: 200 (0 >> 3 + 0, 24) time: 1852214 sent: 1852113 pen: 1 
1855313 rem: 99                                                                                      
[ 2152.214836] lower bound violation: 0                                                                                                                                          
[ 2152.214892] rto: 200 (0 >> 3 + 0, 23) time: 1852214 sent: 1852113 pen: 1 
1852313 rem: 99                                                                                      
[ 2152.216836] lower bound violation: 0                                                                                                                                          
[ 2152.216892] rto: 200 (0 >> 3 + 0, 22) time: 1852216 sent: 1852113 pen: 1 
1852313 rem: 97                                                                                      
[ 2155.212630] lower bound violation: 0                                                                                                                                          
[ 2155.212683] rto: 200 (0 >> 3 + 0, 25) time: 1855212 sent: 1855113 pen: 1 
1858313 rem: 101                                                                                     
[ 2155.271403] lower bound violation: 0                                                                                                                                          
[ 2155.271462] rto: 200 (0 >> 3 + 0, 24) time: 1855271 sent: 1855113 pen: 1 
1855313 rem: 42                                                                                      
[ 2155.271570] lower bound violation: 0                                                                                                                                          
[ 2155.271624] rto: 200 (0 >> 3 + 0, 23) time: 1855271 sent: 1855113 pen: 1 
1855313 rem: 42                                                                                      
[ 2158.247617] lower bound violation: 0                                                                                                                                          
[ 2158.247676] rto: 200 (0 >> 3 + 0, 26) time: 1858247 sent: 1858113 pen: 1 
1861313 rem: 66                                                                                      
[ 2158.308891] lower bound violation: 0                                                                                                                                          
[ 2158.308949] rto: 200 (0 >> 3 + 0, 25) time: 1858308 sent: 1858113 pen: 1 
1858313 rem: 5                                                                                       
[ 2161.267856] lower bound violation: 0                                                                                                                                          
[ 2161.267918] rto: 200 (0 >> 3 + 0, 28) time: 1861267 sent: 1861114 pen: 1 
1864314 rem: 47                                                                                      
[ 2161.268020] lower bound violation: 0                                                                                                                                          
[ 2161.268068] rto: 200 (0 >> 3 + 0, 27) time: 1861268 sent: 1861114 pen: 1 
1861315 rem: 46                                                                                      
[ 2161.268283] lower bound violation: 0                                                                                                                                          
[ 2161.268339] rto: 200 (0 >> 3 + 0, 26) time: 1861268 sent: 1861114 pen: 1 
1861314 rem: 46                                                                                      
[ 2164.483740] lower bound violation: 0                                                                                                                                          
[ 2164.483799] rto: 200 (0 >> 3 + 0, 29) time: 1864483 sent: 1864114 pen: 1 
1867314 rem: 0                                                                                       
[ 2164.485758] lower bound violation: 0                                                                                                                                          
[ 2164.485809] rto: 200 (0 >> 3 + 0, 29) time: 1864485 sent: 1864483 pen: 1 
1864883 rem: 198                                                                                     
[ 2460.739324] rto: 7040 (757 >> 3 + 346, 4) time: 2160739 sent: 2160696 pen: 
1 2174776 rem: 6997                                                                                
[ 2477.769916] rto: 120000 (17147 >> 3 + 1705, 6) time: 2177769 sent: 2174642 
pen: 1 2294642 rem: 116873                                                                         
[ 2484.364919] rto: 69440 (3542 >> 3 + 643, 6) time: 2184364 sent: 2182505 
pen: 1 2302505 rem: 67581                                                                             
[ 2555.105348] rto: 69440 (3542 >> 3 + 643, 6) time: 2255105 sent: 2251946 
pen: 1 2371946 rem: 66281                                                                             
[ 2597.920272] rto: 120000 (17147 >> 3 + 1705, 6) time: 2297920 sent: 2294643 
pen: 1 2414643 rem: 116723                                                                         
[ 2624.616823] rto: 69440 (3542 >> 3 + 643, 6) time: 2324616 sent: 2321386 
pen: 1 2441386 rem: 66210                                                                             
[ 2693.911647] rto: 69440 (3542 >> 3 + 643, 6) time: 2393911 sent: 2390826 
pen: 1 2510826 rem: 66355                                                                             
[ 2763.385982] rto: 69440 (3542 >> 3 + 643, 6) time: 2463385 sent: 2460266 
pen: 1 2580266 rem: 66321                                                                             
[ 2779.512699] rto: 1256 (1556 >> 3 + 434, 1) time: 2479512 sent: 2478219 pen: 
1 2480731 rem: 0                                                                                  
[ 2832.786161] rto: 69440 (3542 >> 3 + 643, 6) time: 2532786 sent: 2529707 
pen: 1 2649707 rem: 66361                                                                             
[ 2851.953268] rto: 120000 (9704 >> 3 + 2426, 7) time: 2551953 sent: 2548934 
pen: 1 2668934 rem: 116981                                                                          
[ 2902.338631] rto: 69440 (3542 >> 3 + 643, 6) time: 2602338 sent: 2599147 
pen: 1 2719147 rem: 66249                                                                             
[ 2957.718611] rto: 120000 (17147 >> 3 + 1705, 8) time: 2657718 sent: 2654643 
pen: 1 2774643 rem: 116925                                                                         
[ 2971.736295] rto: 69440 (3542 >> 3 + 643, 6) time: 2671736 sent: 2668587 
pen: 1 2788587 rem: 66291                                                                             
[ 2972.118479] rto: 120000 (9704 >> 3 + 2426, 7) time: 2672118 sent: 2668934 
pen: 1 2788934 rem: 116816                                                                          
[ 3041.036185] rto: 69440 (3542 >> 3 + 643, 6) time: 2741036 sent: 2738027 
pen: 1 2858027 rem: 66431                                                                             
[ 3091.942676] rto: 120000 (9704 >> 3 + 2426, 7) time: 2791942 sent: 2788934 
pen: 1 2908934 rem: 116992                                                                          
[ 3110.560285] rto: 69440 (3542 >> 3 + 643, 6) time: 2810560 sent: 2807467 
pen: 1 2927467 rem: 66347                                                                             
[ 3180.044502] rto: 69440 (3542 >> 3 + 643, 6) time: 2880044 sent: 2876907 
pen: 1 2996907 rem: 66303                                                                             
[ 3211.952300] rto: 120000 (9704 >> 3 + 2426, 7) time: 2911952 sent: 2908934 
pen: 1 3028934 rem: 116982                                                                          
[ 3288.275909] rto: 120000 (9674 >> 3 + 2484, 9) time: 2988275 sent: 2987173 
pen: 1 3107173 rem: 118898                                                                          
[ 3330.221683] rto: 120000 (200 >> 3 + 200, 13) time: 3030221 sent: 3027658 
pen: 1 3147658 rem: 117437                                                                           
[ 3383.376964] rto: 13296 (1388 >> 3 + 658, 4) time: 3083376 sent: 3082998 
pen: 1 3109590 rem: 12918                                                                             
[ 3408.805976] rto: 120000 (9674 >> 3 + 2484, 9) time: 3108805 sent: 3107174 
pen: 1 3227174 rem: 118369                                                                          
[ 3447.968663] rto: 120000 (200 >> 3 + 200, 13) time: 3147968 sent: 3147658 
pen: 1 3267658 rem: 119690                                                                           
[ 3798.180697] rto: 1482 (1976 >> 3 + 494, 1) time: 3498180 sent: 3497035 pen: 
1 3499999 rem: 337
[ 3798.180827] rto: 741 (1976 >> 3 + 494, 0) time: 3498180 sent: 3497035 pen: 
1 3498517 rem: 0
[ 3801.277029] rto: 1482 (1976 >> 3 + 494, 1) time: 3501276 sent: 3499662 pen: 
1 3502626 rem: 0
[ 3801.277184] rto: 1482 (1976 >> 3 + 494, 1) time: 3501277 sent: 3501277 pen: 
1 3504241 rem: 1482
[ 3804.486861] rto: 1482 (1976 >> 3 + 494, 1) time: 3504486 sent: 3502759 pen: 
1 3505723 rem: 0
[ 3804.487007] rto: 1482 (1976 >> 3 + 494, 1) time: 3504486 sent: 3504486 pen: 
1 3507450 rem: 1482
[ 3812.053012] rto: 2964 (1976 >> 3 + 494, 2) time: 3512052 sent: 3508933 pen: 
1 3514861 rem: 0
[ 3815.238764] rto: 2964 (1976 >> 3 + 494, 2) time: 3515238 sent: 3512053 pen: 
1 3517981 rem: 0
[ 3818.394748] rto: 2964 (1976 >> 3 + 494, 2) time: 3518394 sent: 3515238 pen: 
1 3521166 rem: 0
[ 3821.481936] rto: 2964 (1976 >> 3 + 494, 2) time: 3521481 sent: 3518394 pen: 
1 3524322 rem: 0
[ 3824.873120] rto: 2964 (1976 >> 3 + 494, 2) time: 3524873 sent: 3521482 pen: 
1 3527410 rem: 0
[ 3827.898656] rto: 2964 (1976 >> 3 + 494, 2) time: 3527898 sent: 3524873 pen: 
1 3530801 rem: 0
[ 3830.943112] rto: 2964 (1976 >> 3 + 494, 2) time: 3530943 sent: 3527898 pen: 
1 3533826 rem: 0
[ 3833.974064] rto: 2964 (1976 >> 3 + 494, 2) time: 3533974 sent: 3530943 pen: 
1 3536871 rem: 0
[ 3837.112487] rto: 2964 (1976 >> 3 + 494, 2) time: 3537112 sent: 3533974 pen: 
1 3539902 rem: 0
[ 3840.130296] rto: 2964 (1976 >> 3 + 494, 2) time: 3540130 sent: 3537112 pen: 
1 3543040 rem: 0
[ 3843.191881] rto: 2964 (1976 >> 3 + 494, 2) time: 3543191 sent: 3540130 pen: 
1 3546058 rem: 0
[ 3846.633862] rto: 2964 (1976 >> 3 + 494, 2) time: 3546633 sent: 3543191 pen: 
1 3549119 rem: 0
[ 3849.682215] rto: 2964 (1976 >> 3 + 494, 2) time: 3549682 sent: 3546633 pen: 
1 3552561 rem: 0
[ 3852.728190] rto: 2964 (1976 >> 3 + 494, 2) time: 3552728 sent: 3549682 pen: 
1 3555610 rem: 0
[ 3869.778290] rto: 79136 (14257 >> 3 + 691, 5) time: 3569778 sent: 3564894 
pen: 1 3684894 rem: 74252
[ 3942.001467] rto: 47424 (1976 >> 3 + 494, 6) time: 3642001 sent: 3641648 
pen: 1 3736496 rem: 47071
[ 3948.754452] rto: 79136 (14257 >> 3 + 691, 5) time: 3648754 sent: 3644030 
pen: 1 3764030 rem: 74412
[ 3972.841345] rto: 47168 (1911 >> 3 + 499, 6) time: 3672841 sent: 3672158 
pen: 1 3766494 rem: 46485
[ 3992.364664] rto: 47424 (1976 >> 3 + 494, 6) time: 3692364 sent: 3689072 
pen: 1 3783920 rem: 44132
[ 4019.342183] rto: 47168 (1911 >> 3 + 499, 6) time: 3719342 sent: 3719326 
pen: 1 3813662 rem: 47152
[ 4028.049905] rto: 79136 (14257 >> 3 + 691, 5) time: 3728049 sent: 3723166 
pen: 1 3843166 rem: 74253
[ 4039.530444] rto: 47424 (1976 >> 3 + 494, 6) time: 3739530 sent: 3736496 
pen: 1 3831344 rem: 44390
[ 4067.954752] rto: 47168 (1911 >> 3 + 499, 6) time: 3767954 sent: 3766494 
pen: 1 3860830 rem: 45708
[ 4087.534683] rto: 47424 (1976 >> 3 + 494, 6) time: 3787534 sent: 3783920 
pen: 1 3878768 rem: 43810
[ 4116.817143] rto: 47168 (1911 >> 3 + 499, 6) time: 3816817 sent: 3813662 
pen: 1 3907998 rem: 44013
[ 4134.515420] rto: 47424 (1976 >> 3 + 494, 6) time: 3834515 sent: 3831344 
pen: 1 3926192 rem: 44253
[ 4146.622061] rto: 40592 (3300 >> 3 + 2125, 4) time: 3846622 sent: 3846199 
pen: 1 3927383 rem: 40169
[ 4182.217172] rto: 47424 (1976 >> 3 + 494, 6) time: 3882217 sent: 3878768 
pen: 1 3973616 rem: 43975
[ 4226.387945] rto: 120000 (14257 >> 3 + 691, 6) time: 3926387 sent: 3922303 
pen: 1 4042303 rem: 115916
[ 4228.876327] rto: 85152 (11055 >> 3 + 1280, 5) time: 3928876 sent: 3925792 
pen: 1 4045792 rem: 82068
[ 4229.248393] rto: 47424 (1976 >> 3 + 494, 6) time: 3929248 sent: 3926192 
pen: 1 4021040 rem: 44368
[ 4264.022196] rto: 103072 (11062 >> 3 + 1839, 5) time: 3964022 sent: 3963411 
pen: 1 4083411 rem: 102461
[ 4271.074364] rto: 81184 (3300 >> 3 + 2125, 5) time: 3971074 sent: 3967975 
pen: 1 4087975 rem: 78085
[ 4276.683784] rto: 47424 (1976 >> 3 + 494, 6) time: 3976683 sent: 3973616 
pen: 1 4068464 rem: 44357
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Denys Fedoryshchenko - Jan. 23, 2010, 11:28 p.m.
On Sunday 24 January 2010 00:34:43 Ilpo Järvinen wrote:
> Restored Damian cc, please keep them.
> 
> On Sat, 23 Jan 2010, Denys Fedoryshchenko wrote:
> > On Tuesday 19 January 2010 13:17:51 you wrote:
> > > On Tue, 19 Jan 2010, Denys Fedoryshchenko wrote:
> > > > On Tuesday 19 January 2010 11:10:12 you wrote:
> > > > > Hi,
> > > > > thank you for testing. So srtt and rttvar is zero in any of those
> > > > > cases. Ilpo, it is a bug in tcp_rtt_estimator then, I suppose?
> > > > >
> > > > > There is also a code comment in tcp_input.c, saying:
> > > > > > * NOTE: clamping at TCP_RTO_MIN is not required, current algo
> > > > > > * guarantees that rto is higher.
> > > > >
> > > > > So we either fix tcp_rtt_estimator or simply clamp at TCP_RTO_MIN?
> > > > >
> > > > > Damian
> > > > >
> > > > > > On Monday 11 January 2010 15:02:34 you wrote:
> > > > > >> On Sat, 26 Dec 2009, Denys Fedoryshchenko wrote:
> > > > > >>> Few more dumps. I notice:
> > > > > >>> 1)Ack always equal 1
> > > > > >>> 2)It is usually first segment of data sent (?)
> > > > > >>>
> > > > > >>> Maybe some value not initialised properly?
> > > > > >>
> > > > > >> Can you see if the RTO lower bound is violated (I added some
> > > > > >> printing of vars there too already now if it turns out to be
> > > > > >> something):
> > > > > >>
> > > > > >> diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
> > > > > >> index 65b8ebf..d84469f 100644
> > > > > >> --- a/net/ipv4/tcp_ipv4.c
> > > > > >> +++ b/net/ipv4/tcp_ipv4.c
> > > >
> > > > As i see in code it is rounding RTO to minimum value.
> > > > It fixes my problem seems.
> > > >
> > > > Btw just a bit about my environment - wireless networks (sometimes
> > > > lossy!) with low speed (128-512Kbps) customers working over pppoe.
> > > > Maybe it will give a tip why rtt value is too low.
> > >
> > > What I find most strange in it is the fact that when it triggers for
> > > the first time, the srtt and mdev are zero, not some value in between 0
> > > and 200ms. Therefore I suspect that this case might be something that
> > > we've overlooked where srtt/mdev are not valid at all.
> > >
> > > Maybe the patch below helps...
> >
> > Seems after this patch (and debug patch with warnings) my dmesg is clean.
> 
> Cool, thanks for testing.
> 
> Dave, please send into stable too (besides net-2.6). If we want less strict
> state check we can continue playing with that in net-next, IMHO.
> 
I extend a little bit debug to 
printk("lower bound violation: %u code %u sk_state %u\n", icsk->icsk_rto, 
code,sk->sk_state);

Here is result:
[  566.990065] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  566.990111] rto: 200 (0 >> 3 + 0, 5) time: 266990 sent: 263925 pen: 1 
383925 rem: 0                                                                                           
[  570.058555] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  570.058603] rto: 200 (0 >> 3 + 0, 8) time: 270058 sent: 269790 pen: 1 
272990 rem: 0                                                                                           
[  570.058660] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  570.058698] rto: 200 (0 >> 3 + 0, 8) time: 270058 sent: 270058 pen: 1 
270458 rem: 200                                                                                         
[  573.122550] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  573.122626] rto: 200 (0 >> 3 + 0, 11) time: 273122 sent: 273058 pen: 1 
276258 rem: 136                                                                                        
[  573.122745] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  573.122815] rto: 200 (0 >> 3 + 0, 10) time: 273122 sent: 273058 pen: 1 
273258 rem: 136                                                                                        
[  573.122931] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  573.123001] rto: 200 (0 >> 3 + 0, 9) time: 273122 sent: 273058 pen: 1 
273258 rem: 136                                                                                         
[  576.304338] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  576.304423] rto: 200 (0 >> 3 + 0, 12) time: 276304 sent: 276059 pen: 1 
279259 rem: 0                                                                                          
[  576.326167] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  576.326251] rto: 200 (0 >> 3 + 0, 12) time: 276326 sent: 276304 pen: 1 
276704 rem: 178                                                                                        
[  579.360343] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  579.360427] rto: 200 (0 >> 3 + 0, 15) time: 279360 sent: 279304 pen: 1 
282504 rem: 144                                                                                        
[  582.566834] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  582.566919] rto: 200 (0 >> 3 + 0, 18) time: 282566 sent: 282304 pen: 1 
285504 rem: 0                                                                                          
[  582.567085] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  582.567162] rto: 200 (0 >> 3 + 0, 18) time: 282567 sent: 282567 pen: 1 
282967 rem: 200                                                                                        
[  582.567280] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  582.567351] rto: 200 (0 >> 3 + 0, 17) time: 282567 sent: 282567 pen: 1 
282767 rem: 200                                                                                        
[  585.649877] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  585.649962] rto: 200 (0 >> 3 + 0, 20) time: 285649 sent: 285567 pen: 1 
288767 rem: 118                                                                                        
[  585.650097] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  585.650178] rto: 200 (0 >> 3 + 0, 19) time: 285650 sent: 285567 pen: 1 
285768 rem: 117                                                                                        
[  588.836754] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  588.836845] rto: 200 (0 >> 3 + 0, 22) time: 288836 sent: 288567 pen: 1 
291767 rem: 0                                                                                          
[  588.836970] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  588.837042] rto: 200 (0 >> 3 + 0, 22) time: 288836 sent: 288836 pen: 1 
289236 rem: 200                                                                                        
[  591.902908] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  591.902996] rto: 200 (0 >> 3 + 0, 25) time: 291902 sent: 291837 pen: 1 
295037 rem: 135                                                                                        
[  591.903129] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  591.903205] rto: 200 (0 >> 3 + 0, 24) time: 291903 sent: 291837 pen: 1 
292038 rem: 134                                                                                        
[  595.091391] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  595.091477] rto: 200 (0 >> 3 + 0, 27) time: 295091 sent: 294837 pen: 1 
298037 rem: 0                                                                                          
[  595.091627] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  595.091702] rto: 200 (0 >> 3 + 0, 27) time: 295091 sent: 295091 pen: 1 
295491 rem: 200                                                                                        
[  598.141828] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  598.141913] rto: 200 (0 >> 3 + 0, 30) time: 298141 sent: 298091 pen: 1 
301291 rem: 150                                                                                        
[  598.142043] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  598.142114] rto: 200 (0 >> 3 + 0, 29) time: 298141 sent: 298091 pen: 1 
298291 rem: 150                                                                                        
[  598.142252] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  598.142344] rto: 200 (0 >> 3 + 0, 28) time: 298142 sent: 298091 pen: 1 
298291 rem: 149                                                                                        
[  601.146649] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  601.146734] rto: 200 (0 >> 3 + 0, 31) time: 301146 sent: 301091 pen: 1 
304291 rem: 145                                                                                        
[  601.178998] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  601.179090] rto: 200 (0 >> 3 + 0, 30) time: 301179 sent: 301091 pen: 1 
301291 rem: 112                                                                                        
[  601.179227] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  601.179298] rto: 200 (0 >> 3 + 0, 29) time: 301179 sent: 301091 pen: 1 
301291 rem: 112                                                                                        
[  604.193304] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  604.193389] rto: 200 (0 >> 3 + 0, 32) time: 304193 sent: 304091 pen: 1 
307291 rem: 98                                                                                         
[  604.193518] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  604.193589] rto: 200 (0 >> 3 + 0, 31) time: 304193 sent: 304091 pen: 1 
304291 rem: 98                                                                                         
[  604.193706] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  604.193776] rto: 200 (0 >> 3 + 0, 30) time: 304193 sent: 304091 pen: 1 
304291 rem: 98                                                                                         
[  607.341327] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  607.341412] rto: 200 (0 >> 3 + 0, 33) time: 307341 sent: 307091 pen: 1 
310291 rem: 0                                                                                          
[  607.370345] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  607.370427] rto: 200 (0 >> 3 + 0, 33) time: 307370 sent: 307341 pen: 1 
307741 rem: 171                                                                                        
[  607.370657] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  607.370730] rto: 200 (0 >> 3 + 0, 32) time: 307370 sent: 307341 pen: 1 
307541 rem: 171                                                                                        
[  610.437075] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  610.437161] rto: 200 (0 >> 3 + 0, 35) time: 310437 sent: 310341 pen: 1 
313541 rem: 104                                                                                        
[  610.437302] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  610.437374] rto: 200 (0 >> 3 + 0, 34) time: 310437 sent: 310341 pen: 1 
310541 rem: 104                                                                                        
[  610.437497] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  610.437567] rto: 200 (0 >> 3 + 0, 33) time: 310437 sent: 310341 pen: 1 
310541 rem: 104                                                                                        
[  613.429680] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  613.429770] rto: 200 (0 >> 3 + 0, 36) time: 313429 sent: 313341 pen: 1 
316541 rem: 112                                                                                        
[  613.429899] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  613.429970] rto: 200 (0 >> 3 + 0, 35) time: 313429 sent: 313341 pen: 1 
313541 rem: 112                                                                                        
[  613.430087] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  613.430164] rto: 200 (0 >> 3 + 0, 34) time: 313430 sent: 313341 pen: 1 
313542 rem: 111                                                                                        
[  616.644279] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  616.644364] rto: 200 (0 >> 3 + 0, 37) time: 316644 sent: 316341 pen: 1 
319541 rem: 0                                                                                          
[  616.644500] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  616.644572] rto: 200 (0 >> 3 + 0, 37) time: 316644 sent: 316644 pen: 1 
317044 rem: 200                                                                                        
[  616.644689] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  616.644760] rto: 200 (0 >> 3 + 0, 36) time: 316644 sent: 316644 pen: 1 
316844 rem: 200                                                                                        
[  617.028542] rto: 120000 (788 >> 3 + 266, 10) time: 317028 sent: 313993 pen: 
1 433993 rem: 116965                                                                              
[  619.711969] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  619.712050] rto: 200 (0 >> 3 + 0, 39) time: 319712 sent: 319644 pen: 1 
322844 rem: 132                                                                                        
[  619.712169] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  619.712240] rto: 200 (0 >> 3 + 0, 38) time: 319712 sent: 319644 pen: 1 
319844 rem: 132                                                                                        
[  619.712364] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  619.712435] rto: 200 (0 >> 3 + 0, 37) time: 319712 sent: 319644 pen: 1 
319844 rem: 132                                                                                        
[  622.908447] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  622.908531] rto: 200 (0 >> 3 + 0, 40) time: 322908 sent: 322644 pen: 1 
325844 rem: 0                                                                                          
[  622.909274] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  622.909347] rto: 200 (0 >> 3 + 0, 40) time: 322909 sent: 322908 pen: 1 
323308 rem: 199                                                                                        
[  622.914930] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  622.915014] rto: 200 (0 >> 3 + 0, 39) time: 322914 sent: 322908 pen: 1 
323108 rem: 194                                                                                        
[  625.975145] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  625.975232] rto: 200 (0 >> 3 + 0, 42) time: 325975 sent: 325909 pen: 1 
329109 rem: 134                                                                                        
[  625.975350] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  625.975422] rto: 200 (0 >> 3 + 0, 41) time: 325975 sent: 325909 pen: 1 
326109 rem: 134                                                                                        
[  625.975538] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  625.975609] rto: 200 (0 >> 3 + 0, 40) time: 325975 sent: 325909 pen: 1 
326109 rem: 134                                                                                        
[  629.187199] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  629.187286] rto: 200 (0 >> 3 + 0, 43) time: 329187 sent: 328909 pen: 1 
332109 rem: 0                                                                                          
[  629.187454] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  629.187529] rto: 200 (0 >> 3 + 0, 43) time: 329187 sent: 329187 pen: 1 
329587 rem: 200                                                                                        
[  629.187646] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  629.187717] rto: 200 (0 >> 3 + 0, 42) time: 329187 sent: 329187 pen: 1 
329387 rem: 200                                                                                        
[  632.232822] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  632.232907] rto: 200 (0 >> 3 + 0, 45) time: 332232 sent: 332187 pen: 1 
335387 rem: 155                                                                                        
[  632.250500] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  632.250585] rto: 200 (0 >> 3 + 0, 44) time: 332250 sent: 332187 pen: 1 
332388 rem: 137                                                                                        
[  632.250714] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  632.250785] rto: 200 (0 >> 3 + 0, 43) time: 332250 sent: 332187 pen: 1 
332387 rem: 137                                                                                        
[  635.247889] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  635.247974] rto: 200 (0 >> 3 + 0, 46) time: 335247 sent: 335187 pen: 1 
338387 rem: 140                                                                                        
[  635.248416] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  635.248490] rto: 200 (0 >> 3 + 0, 45) time: 335248 sent: 335187 pen: 1 
335387 rem: 139                                                                                        
[  635.251046] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  635.251122] rto: 200 (0 >> 3 + 0, 44) time: 335251 sent: 335187 pen: 1 
335387 rem: 136                                                                                        
[  638.434799] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  638.434883] rto: 200 (0 >> 3 + 0, 47) time: 338434 sent: 338187 pen: 1 
341387 rem: 0                                                                                          
[  638.435018] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  638.435090] rto: 200 (0 >> 3 + 0, 47) time: 338435 sent: 338434 pen: 1 
338834 rem: 199                                                                                        
[  638.435215] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  638.435993] rto: 200 (0 >> 3 + 0, 46) time: 338435 sent: 338434 pen: 1 
338634 rem: 199                                                                                        
[  641.501303] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  641.501380] rto: 200 (0 >> 3 + 0, 49) time: 341501 sent: 341435 pen: 1 
344635 rem: 134                                                                                        
[  641.501501] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  641.501571] rto: 200 (0 >> 3 + 0, 48) time: 341501 sent: 341435 pen: 1 
341635 rem: 134                                                                                        
[  641.501687] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  641.501757] rto: 200 (0 >> 3 + 0, 47) time: 341501 sent: 341435 pen: 1 
341635 rem: 134                                                                                        
[  644.518586] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  644.518672] rto: 200 (0 >> 3 + 0, 50) time: 344518 sent: 344435 pen: 1 
347635 rem: 117                                                                                        
[  644.518849] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  644.518930] rto: 200 (0 >> 3 + 0, 49) time: 344518 sent: 344435 pen: 1 
344635 rem: 117                                                                                        
[  644.519071] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  644.519158] rto: 200 (0 >> 3 + 0, 48) time: 344519 sent: 344435 pen: 1 
344636 rem: 116                                                                                        
[  647.725632] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  647.725717] rto: 200 (0 >> 3 + 0, 51) time: 347725 sent: 347435 pen: 1 
350635 rem: 0                                                                                          
[  647.725850] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  647.725921] rto: 200 (0 >> 3 + 0, 51) time: 347725 sent: 347725 pen: 1 
348125 rem: 200                                                                                        
[  647.729343] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  647.729417] rto: 200 (0 >> 3 + 0, 50) time: 347729 sent: 347725 pen: 1 
347925 rem: 196                                                                                        
[  650.787543] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  650.787619] rto: 200 (0 >> 3 + 0, 53) time: 350787 sent: 350726 pen: 1 
353926 rem: 139                                                                                        
[  650.798651] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  650.798749] rto: 200 (0 >> 3 + 0, 52) time: 350798 sent: 350726 pen: 1 
350926 rem: 128                                                                                        
[  650.805039] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  650.805123] rto: 200 (0 >> 3 + 0, 51) time: 350805 sent: 350726 pen: 1 
350926 rem: 121                                                                                        
[  653.801712] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  653.801788] rto: 200 (0 >> 3 + 0, 54) time: 353801 sent: 353726 pen: 1 
356926 rem: 125                                                                                        
[  653.801937] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  653.802023] rto: 200 (0 >> 3 + 0, 53) time: 353802 sent: 353726 pen: 1 
353926 rem: 124                                                                                        
[  653.802475] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  653.802548] rto: 200 (0 >> 3 + 0, 52) time: 353802 sent: 353726 pen: 1 
353926 rem: 124                                                                                        
[  656.985567] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  656.985653] rto: 200 (0 >> 3 + 0, 55) time: 356985 sent: 356726 pen: 1 
359926 rem: 0                                                                                          
[  656.986226] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  656.986299] rto: 200 (0 >> 3 + 0, 55) time: 356986 sent: 356985 pen: 1 
357385 rem: 199                                                                                        
[  656.986416] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  656.986486] rto: 200 (0 >> 3 + 0, 54) time: 356986 sent: 356985 pen: 1 
357185 rem: 199                                                                                        
[  660.042091] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  660.042168] rto: 200 (0 >> 3 + 0, 57) time: 360042 sent: 359985 pen: 1 
363185 rem: 143                                                                                        
[  660.042286] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  660.042357] rto: 200 (0 >> 3 + 0, 56) time: 360042 sent: 359985 pen: 1 
360185 rem: 143                                                                                        
[  660.076230] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  660.076315] rto: 200 (0 >> 3 + 0, 55) time: 360076 sent: 359985 pen: 1 
360185 rem: 109                                                                                        
[  663.256655] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  663.256731] rto: 200 (0 >> 3 + 0, 58) time: 363256 sent: 362985 pen: 1 
366185 rem: 0                                                                                          
[  663.341934] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  663.342010] rto: 200 (0 >> 3 + 0, 58) time: 363341 sent: 363256 pen: 1 
363656 rem: 115                                                                                        
[  663.428067] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  663.428156] rto: 200 (0 >> 3 + 0, 57) time: 363428 sent: 363256 pen: 1 
363457 rem: 28                                                                                         
[  666.308896] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  666.308980] rto: 200 (0 >> 3 + 0, 60) time: 366308 sent: 366256 pen: 1 
369456 rem: 148                                                                                        
[  666.309110] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  666.309186] rto: 200 (0 >> 3 + 0, 59) time: 366309 sent: 366256 pen: 1 
366457 rem: 147                                                                                        
[  666.309315] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  666.309386] rto: 200 (0 >> 3 + 0, 58) time: 366309 sent: 366256 pen: 1 
366456 rem: 147                                                                                        
[  669.519782] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  669.519866] rto: 200 (0 >> 3 + 0, 61) time: 369519 sent: 369256 pen: 1 
372456 rem: 0                                                                                          
[  669.520011] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  669.520083] rto: 200 (0 >> 3 + 0, 61) time: 369520 sent: 369519 pen: 1 
369919 rem: 199                                                                                        
[  669.520206] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  669.520286] rto: 200 (0 >> 3 + 0, 60) time: 369520 sent: 369519 pen: 1 
369719 rem: 199                                                                                        
[  672.641672] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  672.641756] rto: 200 (0 >> 3 + 0, 63) time: 372641 sent: 372519 pen: 1 
375719 rem: 78                                                                                         
[  672.642325] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  672.642407] rto: 200 (0 >> 3 + 0, 62) time: 372642 sent: 372519 pen: 1 
372719 rem: 77                                                                                         
[  672.642524] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  672.642596] rto: 200 (0 >> 3 + 0, 61) time: 372642 sent: 372519 pen: 1 
372719 rem: 77                                                                                         
[  675.789437] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  675.789522] rto: 200 (0 >> 3 + 0, 64) time: 375789 sent: 375519 pen: 1 
378719 rem: 0                                                                                          
[  675.789657] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  675.789727] rto: 200 (0 >> 3 + 0, 64) time: 375789 sent: 375789 pen: 1 
376189 rem: 200                                                                                        
[  675.813158] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  675.813242] rto: 200 (0 >> 3 + 0, 63) time: 375813 sent: 375789 pen: 1 
375989 rem: 176                                                                                        
[  678.902625] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  678.902689] rto: 200 (0 >> 3 + 0, 66) time: 378902 sent: 378789 pen: 1 
381989 rem: 87                                                                                         
[  678.902808] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  678.902869] rto: 200 (0 >> 3 + 0, 65) time: 378902 sent: 378789 pen: 1 
378989 rem: 87                                                                                         
[  678.902967] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  678.903027] rto: 200 (0 >> 3 + 0, 64) time: 378903 sent: 378789 pen: 1 
378989 rem: 86                                                                                         
[  682.086610] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  682.086673] rto: 200 (0 >> 3 + 0, 67) time: 382086 sent: 381789 pen: 1 
384989 rem: 0                                                                                          
[  682.086823] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  682.086885] rto: 200 (0 >> 3 + 0, 67) time: 382086 sent: 382086 pen: 1 
382486 rem: 200                                                                                        
[  682.086988] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  682.087042] rto: 200 (0 >> 3 + 0, 66) time: 382087 sent: 382086 pen: 1 
382286 rem: 199                                                                                        
[  685.177400] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
[  685.177460] rto: 200 (0 >> 3 + 0, 69) time: 385177 sent: 385086 pen: 1 
388286 rem: 109                                                                                        
[  685.177566] lower bound violation: 0 code 1 sk_state 1
[  685.177630] rto: 200 (0 >> 3 + 0, 68) time: 385177 sent: 385086 pen: 1 
385286 rem: 109
[  685.177734] lower bound violation: 0 code 1 sk_state 1
[  685.177790] rto: 200 (0 >> 3 + 0, 67) time: 385177 sent: 385086 pen: 1 
385286 rem: 109
[  688.339503] lower bound violation: 0 code 1 sk_state 1
[  688.339565] rto: 200 (0 >> 3 + 0, 70) time: 388339 sent: 388086 pen: 1 
391286 rem: 0
[  688.339684] lower bound violation: 0 code 1 sk_state 1
[  688.339745] rto: 200 (0 >> 3 + 0, 70) time: 388339 sent: 388339 pen: 1 
388739 rem: 200
[  688.339844] lower bound violation: 0 code 1 sk_state 1
[  688.339896] rto: 200 (0 >> 3 + 0, 69) time: 388339 sent: 388339 pen: 1 
388539 rem: 200
[  691.925180] lower bound violation: 0 code 1 sk_state 1
[  691.925242] rto: 200 (0 >> 3 + 0, 72) time: 391925 sent: 391339 pen: 1 
394539 rem: 0
[  692.010074] lower bound violation: 0 code 1 sk_state 1
[  692.010131] rto: 200 (0 >> 3 + 0, 72) time: 392009 sent: 391925 pen: 1 
392325 rem: 116
[  692.096188] lower bound violation: 0 code 1 sk_state 1
[  692.096254] rto: 200 (0 >> 3 + 0, 71) time: 392096 sent: 391925 pen: 1 
392126 rem: 29
[  694.474680] lower bound violation: 0 code 1 sk_state 1
[  694.474742] rto: 200 (0 >> 3 + 0, 73) time: 394474 sent: 393325 pen: 1 
394925 rem: 0
[  694.475751] lower bound violation: 0 code 1 sk_state 1
[  694.475810] rto: 200 (0 >> 3 + 0, 73) time: 394475 sent: 394474 pen: 1 
394874 rem: 199
[  694.475918] lower bound violation: 0 code 1 sk_state 1
[  694.475975] rto: 200 (0 >> 3 + 0, 72) time: 394475 sent: 394474 pen: 1 
394674 rem: 199
[  697.572814] lower bound violation: 0 code 1 sk_state 1
[  697.572877] rto: 200 (0 >> 3 + 0, 75) time: 397572 sent: 397474 pen: 1 
400674 rem: 102
[  697.572986] lower bound violation: 0 code 1 sk_state 1
[  697.573052] rto: 200 (0 >> 3 + 0, 74) time: 397573 sent: 397474 pen: 1 
397674 rem: 101
[  697.573159] lower bound violation: 0 code 1 sk_state 1
[  697.573211] rto: 200 (0 >> 3 + 0, 73) time: 397573 sent: 397474 pen: 1 
397674 rem: 101
[  700.728072] lower bound violation: 0 code 1 sk_state 1
[  700.728135] rto: 200 (0 >> 3 + 0, 76) time: 400728 sent: 400474 pen: 1 
403674 rem: 0
[  700.734010] lower bound violation: 0 code 1 sk_state 1
[  700.734079] rto: 200 (0 >> 3 + 0, 76) time: 400734 sent: 400728 pen: 1 
401128 rem: 194
[  700.734191] lower bound violation: 0 code 1 sk_state 1
[  700.734944] rto: 200 (0 >> 3 + 0, 75) time: 400734 sent: 400728 pen: 1 
400928 rem: 194
[  703.779459] lower bound violation: 0 code 1 sk_state 1
[  703.779521] rto: 200 (0 >> 3 + 0, 78) time: 403779 sent: 403729 pen: 1 
406929 rem: 150
[  703.779628] lower bound violation: 0 code 1 sk_state 1
[  703.779680] rto: 200 (0 >> 3 + 0, 77) time: 403779 sent: 403729 pen: 1 
403929 rem: 150
[  703.779797] lower bound violation: 0 code 1 sk_state 1
[  703.779850] rto: 200 (0 >> 3 + 0, 76) time: 403779 sent: 403729 pen: 1 
403929 rem: 150
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Damian Lukowski - Jan. 25, 2010, 12:12 p.m.
Hi,
considering Denys' latest tests, I think we should bound
at TCP_RTO_MIN inside __tcp_set_rto().
Look at the following piece:
> [  604.193389] rto: 200 (0 >> 3 + 0, 32) time: 304193 sent: 304091 pen: 1 307291 rem: 98                                                                                         
> [  604.193518] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
> [  604.193589] rto: 200 (0 >> 3 + 0, 31) time: 304193 sent: 304091 pen: 1 304291 rem: 98                                                                                         
> [  604.193706] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
> [  604.193776] rto: 200 (0 >> 3 + 0, 30) time: 304193 sent: 304091 pen: 1 304291 rem: 98                                                                                         
> [  607.341327] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
> [  607.341412] rto: 200 (0 >> 3 + 0, 33) time: 307341 sent: 307091 pen: 1 310291 rem: 0  

We have a burst of three incoming ICMPs, not triggering retransmissions because
of rem > 0. Nevertheless, there is an increase of icsk_backoff by four
within 3100ms, with no ICMPs in between.
For me, this is explainable by the broken mdev/rtt issue together with
bursty ICMP replies.

- At t=0, RTT is at 0.2 seconds when connectivity breaks
- At t=3, TCP has emitted 4 eponentially backed-off retransmits,
  and icsk_rto is at 3.2s.
- At t=3+eps, three of four ICMPs arrive in one burst.
- Due to broken mdev, rto is reset to 0.2s inside tcp_v4_err(),
  independent of icsk_backoff.

Damian

> Restored Damian cc, please keep them.
> 
> On Sat, 23 Jan 2010, Denys Fedoryshchenko wrote:
>> On Tuesday 19 January 2010 13:17:51 you wrote:
>>> On Tue, 19 Jan 2010, Denys Fedoryshchenko wrote:
>>>> On Tuesday 19 January 2010 11:10:12 you wrote:
>>>>> Hi,
>>>>> thank you for testing. So srtt and rttvar is zero in any of those
>>>>> cases. Ilpo, it is a bug in tcp_rtt_estimator then, I suppose?
>>>>>
>>>>> There is also a code comment in tcp_input.c, saying:
>>>>>> * NOTE: clamping at TCP_RTO_MIN is not required, current algo
>>>>>> * guarantees that rto is higher.
>>>>> So we either fix tcp_rtt_estimator or simply clamp at TCP_RTO_MIN?
>>>>>
>>>>> Damian
>>>>>
>>>>>> On Monday 11 January 2010 15:02:34 you wrote:
>>>>>>> On Sat, 26 Dec 2009, Denys Fedoryshchenko wrote:
>>>>>>>> Few more dumps. I notice:
>>>>>>>> 1)Ack always equal 1
>>>>>>>> 2)It is usually first segment of data sent (?)
>>>>>>>>
>>>>>>>> Maybe some value not initialised properly?
>>>>>>> Can you see if the RTO lower bound is violated (I added some
>>>>>>> printing of vars there too already now if it turns out to be
>>>>>>> something):
>>>>>>>
>>>>>>> diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
>>>>>>> index 65b8ebf..d84469f 100644
>>>>>>> --- a/net/ipv4/tcp_ipv4.c
>>>>>>> +++ b/net/ipv4/tcp_ipv4.c
>>>> As i see in code it is rounding RTO to minimum value.
>>>> It fixes my problem seems.
>>>>
>>>> Btw just a bit about my environment - wireless networks (sometimes
>>>> lossy!) with low speed (128-512Kbps) customers working over pppoe. Maybe
>>>> it will give a tip why rtt value is too low.
>>> What I find most strange in it is the fact that when it triggers for the
>>> first time, the srtt and mdev are zero, not some value in between 0 and
>>> 200ms. Therefore I suspect that this case might be something that we've
>>> overlooked where srtt/mdev are not valid at all.
>>>
>>> Maybe the patch below helps...
>>>
>> Seems after this patch (and debug patch with warnings) my dmesg is clean.
> 
> Cool, thanks for testing.
> 
> Dave, please send into stable too (besides net-2.6). If we want less strict 
> state check we can continue playing with that in net-next, IMHO.
> 

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Ilpo Järvinen - Jan. 27, 2010, 12:36 p.m.
On Mon, 25 Jan 2010, Damian Lukowski wrote:

> considering Denys' latest tests, I think we should bound
> at TCP_RTO_MIN inside __tcp_set_rto().
> Look at the following piece:
> > [  604.193389] rto: 200 (0 >> 3 + 0, 32) time: 304193 sent: 304091 pen: 1 307291 rem: 98                                                                                         
> > [  604.193518] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
> > [  604.193589] rto: 200 (0 >> 3 + 0, 31) time: 304193 sent: 304091 pen: 1 304291 rem: 98                                                                                         
> > [  604.193706] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
> > [  604.193776] rto: 200 (0 >> 3 + 0, 30) time: 304193 sent: 304091 pen: 1 304291 rem: 98                                                                                         
> > [  607.341327] lower bound violation: 0 code 1 sk_state 1                                                                                                                        
> > [  607.341412] rto: 200 (0 >> 3 + 0, 33) time: 307341 sent: 307091 pen: 1 310291 rem: 0  
> 
> We have a burst of three incoming ICMPs, not triggering retransmissions because
> of rem > 0. Nevertheless, there is an increase of icsk_backoff by four
> within 3100ms, with no ICMPs in between.
> For me, this is explainable by the broken mdev/rtt issue together with
> bursty ICMP replies.

Unless they are for a different connection? We might have to print sk (%p) 
in all those printouts to be sure which maps to which. If a peer becomes 
unreachable, it may well have multiple connections open (this was a 
proxy, iirc?).

Patch

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 65b8ebf..ebcfcf6 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -401,6 +401,9 @@  void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
 		 * (see draft-zimmermann-tcp-lcd) */
 		if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH)
 			break;
+		/* A bit too strict, just want to be on the safe side for now */
+		if (sk->sk_state != TCP_ESTABLISHED)
+			break;
 		if (seq != tp->snd_una  || !icsk->icsk_retransmits ||
 		    !icsk->icsk_backoff)
 			break;