| Message ID | 1489100780.28631.25.camel@edumazet-glaptop3.roam.corp.google.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
On 3/9/2017 5:06 PM, Eric Dumazet wrote: > On Thu, 2017-03-09 at 16:35 -0600, Tom Lendacky wrote: >> On 3/9/2017 4:17 PM, Jeremy Linton wrote: >>> Hi, >>> >>> On 03/09/2017 03:39 PM, Tom Lendacky wrote: >>>> On 3/9/2017 3:26 PM, Jeremy Linton wrote: >>>>> Hi, >>>> >>>> Hi Jeremy, >>>> >>>> I'll have a look at it. Can you send me your kernel config just in >>>> case? >>> >>> Sure, i will send it to you off list to avoid spamming everyone with a >>> 43k gziped file. >>> >> >> I'm able to recreate the problem with my current config. If I revert >> patch 39e6c8208d7b ("net: solve a NAPI race"), then the problem goes >> away. >> >> Eric, any thoughts on this? I'm guessing the driver should check that >> napi_complete_done returns true before enabling IRQs... >> >> Thanks, >> Tom > > Yes, it seems this driver has a conditional disable_irq_nosync() > following the napi_schedule_prep() > > So it probably needs the same for the enable_irq() side. I verified that the issue goes away when the return value for napi_complete_done() is checked. I'll prepare a patch for both calls in the driver. > > This would be broken with busy polling anyway, before my patch. Yes, I see that busy polling went into 4.10 so I'll submit it back to 4.10 stable as well. Thanks, Tom > > diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c > index 248f60d171a5a0ce76744a95e2d59039939e6538..c47a3a93f034ab608286d1ae343e9b7778063df8 100644 > --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c > +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c > @@ -2272,9 +2272,8 @@ static int xgbe_one_poll(struct napi_struct *napi, int budget) > processed = xgbe_rx_poll(channel, budget); > > /* If we processed everything, we are done */ > - if (processed < budget) { > - /* Turn off polling */ > - napi_complete_done(napi, processed); > + if (processed < budget && > + napi_complete_done(napi, processed)) { > > /* Enable Tx and Rx interrupts */ > if (pdata->channel_irq_mode) > >
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index 248f60d171a5a0ce76744a95e2d59039939e6538..c47a3a93f034ab608286d1ae343e9b7778063df8 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -2272,9 +2272,8 @@ static int xgbe_one_poll(struct napi_struct *napi, int budget) processed = xgbe_rx_poll(channel, budget); /* If we processed everything, we are done */ - if (processed < budget) { - /* Turn off polling */ - napi_complete_done(napi, processed); + if (processed < budget && + napi_complete_done(napi, processed)) { /* Enable Tx and Rx interrupts */ if (pdata->channel_irq_mode)