| Message ID | 529C2E01.3090005@huawei.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Mon, Dec 02, 2013 at 02:51:45PM +0800, Wang Weidong wrote: > From: Wang Weidong <wangweidong1@huawei.com> > > when I setted the max_burst to 0, do the lksctp-tools I got hang. > I found sctp_transport_burst_limited would make the cwnd to 0. > so I make the max_burst min value to 1. > Signed-off-by: Wang Weidong <wangweidong1@huawei.com> > --- > net/sctp/sysctl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c > index 7637e8e..46832d3 100644 > --- a/net/sctp/sysctl.c > +++ b/net/sctp/sysctl.c > @@ -135,7 +135,7 @@ static struct ctl_table sctp_net_table[] = { > .maxlen = sizeof(int), > .mode = 0644, > .proc_handler = proc_dointvec_minmax, > - .extra1 = &zero, > + .extra1 = &one, > .extra2 = &int_max > }, > { > -- > 1.7.12 > > This seems like a band-aid to me. There are a few things wrong: 1) You can also set the the max_burst via setsockopt, and so this would need to be checked in that path as well. 2) I don't see how having a cwnd of zero would cause a hang. It looks like a cwnd of zero would perpetually place the association in a slow start state, which is silly but not illegal. Please investigate the acutally root cause of the problem before just avoiding it like this. Thanks! Neil -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2013/12/2 19:56, Neil Horman wrote: > On Mon, Dec 02, 2013 at 02:51:45PM +0800, Wang Weidong wrote: >> From: Wang Weidong <wangweidong1@huawei.com> >> >> when I setted the max_burst to 0, do the lksctp-tools I got hang. >> I found sctp_transport_burst_limited would make the cwnd to 0. >> so I make the max_burst min value to 1. >> Signed-off-by: Wang Weidong <wangweidong1@huawei.com> >> --- >> net/sctp/sysctl.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c >> index 7637e8e..46832d3 100644 >> --- a/net/sctp/sysctl.c >> +++ b/net/sctp/sysctl.c >> @@ -135,7 +135,7 @@ static struct ctl_table sctp_net_table[] = { >> .maxlen = sizeof(int), >> .mode = 0644, >> .proc_handler = proc_dointvec_minmax, >> - .extra1 = &zero, >> + .extra1 = &one, >> .extra2 = &int_max >> }, >> { >> -- >> 1.7.12 >> >> > > > This seems like a band-aid to me. There are a few things wrong: > > 1) You can also set the the max_burst via setsockopt, and so this would need to > be checked in that path as well. > > 2) I don't see how having a cwnd of zero would cause a hang. It looks like a > cwnd of zero would perpetually place the association in a slow start state, > which is silly but not illegal. > Hm, Good suggestions. Ok, I will try it again and find the root cause. Thanks! > Please investigate the acutally root cause of the problem before just avoiding > it like this. > > Thanks! > Neil > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Dec 2, 2013, at 12:56 PM, Neil Horman <nhorman@tuxdriver.com> wrote: > On Mon, Dec 02, 2013 at 02:51:45PM +0800, Wang Weidong wrote: >> From: Wang Weidong <wangweidong1@huawei.com> >> >> when I setted the max_burst to 0, do the lksctp-tools I got hang. >> I found sctp_transport_burst_limited would make the cwnd to 0. >> so I make the max_burst min value to 1. >> Signed-off-by: Wang Weidong <wangweidong1@huawei.com> >> --- >> net/sctp/sysctl.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c >> index 7637e8e..46832d3 100644 >> --- a/net/sctp/sysctl.c >> +++ b/net/sctp/sysctl.c >> @@ -135,7 +135,7 @@ static struct ctl_table sctp_net_table[] = { >> .maxlen = sizeof(int), >> .mode = 0644, >> .proc_handler = proc_dointvec_minmax, >> - .extra1 = &zero, >> + .extra1 = &one, >> .extra2 = &int_max >> }, >> { >> -- >> 1.7.12 >> >> > > > This seems like a band-aid to me. There are a few things wrong: > > 1) You can also set the the max_burst via setsockopt, and so this would need to > be checked in that path as well. > > 2) I don't see how having a cwnd of zero would cause a hang. It looks like a > cwnd of zero would perpetually place the association in a slow start state, > which is silly but not illegal. > > Please investigate the acutally root cause of the problem before just avoiding > it like this. I second this. Please note the using max_burst of in the socket option means that you deactivate max_burst, not that you actually use the value 0. See http://tools.ietf.org/html/rfc6458#section-8.1.24 I FreeBSD we use the sysctl variable as the default for sockets. Therefore max_burst is a valid value, it just disables max_burst. Best regards Michael > > Thanks! > Neil > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12/02/2013 07:03 AM, Wang Weidong wrote: > On 2013/12/2 19:56, Neil Horman wrote: >> On Mon, Dec 02, 2013 at 02:51:45PM +0800, Wang Weidong wrote: >>> From: Wang Weidong <wangweidong1@huawei.com> >>> >>> when I setted the max_burst to 0, do the lksctp-tools I got hang. >>> I found sctp_transport_burst_limited would make the cwnd to 0. >>> so I make the max_burst min value to 1. >>> Signed-off-by: Wang Weidong <wangweidong1@huawei.com> >>> --- >>> net/sctp/sysctl.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c >>> index 7637e8e..46832d3 100644 >>> --- a/net/sctp/sysctl.c >>> +++ b/net/sctp/sysctl.c >>> @@ -135,7 +135,7 @@ static struct ctl_table sctp_net_table[] = { >>> .maxlen = sizeof(int), >>> .mode = 0644, >>> .proc_handler = proc_dointvec_minmax, >>> - .extra1 = &zero, >>> + .extra1 = &one, >>> .extra2 = &int_max >>> }, >>> { >>> -- >>> 1.7.12 >>> >>> >> >> >> This seems like a band-aid to me. There are a few things wrong: >> >> 1) You can also set the the max_burst via setsockopt, and so this would need to >> be checked in that path as well. >> >> 2) I don't see how having a cwnd of zero would cause a hang. It looks like a >> cwnd of zero would perpetually place the association in a slow start state, >> which is silly but not illegal. >> > > Hm, Good suggestions. Ok, I will try it again and find the root cause. > Thanks! It's really simple. sctp_transport_burst_limited() should simply do nothing if max_burst is 0, essentially allowing unlimited bursts. -vlad > >> Please investigate the acutally root cause of the problem before just avoiding >> it like this. >> >> Thanks! >> Neil >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-sctp" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2013/12/2 22:51, Vlad Yasevich wrote: > On 12/02/2013 07:03 AM, Wang Weidong wrote: >> On 2013/12/2 19:56, Neil Horman wrote: >>> On Mon, Dec 02, 2013 at 02:51:45PM +0800, Wang Weidong wrote: >>>> From: Wang Weidong <wangweidong1@huawei.com> >>>> >>>> when I setted the max_burst to 0, do the lksctp-tools I got hang. >>>> I found sctp_transport_burst_limited would make the cwnd to 0. >>>> so I make the max_burst min value to 1. >>>> Signed-off-by: Wang Weidong <wangweidong1@huawei.com> >>>> --- >>>> net/sctp/sysctl.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c >>>> index 7637e8e..46832d3 100644 >>>> --- a/net/sctp/sysctl.c >>>> +++ b/net/sctp/sysctl.c >>>> @@ -135,7 +135,7 @@ static struct ctl_table sctp_net_table[] = { >>>> .maxlen = sizeof(int), >>>> .mode = 0644, >>>> .proc_handler = proc_dointvec_minmax, >>>> - .extra1 = &zero, >>>> + .extra1 = &one, >>>> .extra2 = &int_max >>>> }, >>>> { >>>> -- >>>> 1.7.12 >>>> >>>> >>> >>> >>> This seems like a band-aid to me. There are a few things wrong: >>> >>> 1) You can also set the the max_burst via setsockopt, and so this would need to >>> be checked in that path as well. >>> >>> 2) I don't see how having a cwnd of zero would cause a hang. It looks like a >>> cwnd of zero would perpetually place the association in a slow start state, >>> which is silly but not illegal. >>> >> >> Hm, Good suggestions. Ok, I will try it again and find the root cause. >> Thanks! > > It's really simple. sctp_transport_burst_limited() should simply do > nothing if max_burst is 0, essentially allowing unlimited bursts. > > -vlad > I will add the a check of max_burst, if max_burst is 0, just do nothing. Michael point out that it just disable max_burst which declared in rfc6458#section-8.1.24 as well. Thanks. >> >>> Please investigate the acutally root cause of the problem before just avoiding >>> it like this. >>> >>> Thanks! >>> Neil >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-sctp" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >>> >> >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c index 7637e8e..46832d3 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -135,7 +135,7 @@ static struct ctl_table sctp_net_table[] = { .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, - .extra1 = &zero, + .extra1 = &one, .extra2 = &int_max }, {