| Message ID | 201102101232.50526.rusty@rustcorp.com.au |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, Feb 10, 2011 at 12:32:50PM +1030, Rusty Russell wrote: > From: "Bruce Rogers" <brogers@novell.com> > > Under harsh testing conditions, including low memory, the guest would > stop receiving packets. With this patch applied we no longer see any > problems in the driver while performing these tests for extended periods > of time. > > Make sure napi is scheduled subsequent to each napi_enable. > > Signed-off-by: Bruce Rogers <brogers@novell.com> > Signed-off-by: Olaf Kirch <okir@suse.de> > Cc: stable@kernel.org > Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Rusty, so this is 2.6.38 material - you'll send this to Linus? Or DaveM? > --- > drivers/net/virtio_net.c | 27 ++++++++++++++++----------- > 1 file changed, 16 insertions(+), 11 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -446,6 +446,20 @@ static void skb_recv_done(struct virtque > } > } > > +static void virtnet_napi_enable(struct virtnet_info *vi) > +{ > + napi_enable(&vi->napi); > + > + /* If all buffers were filled by other side before we napi_enabled, we > + * won't get another interrupt, so process any outstanding packets > + * now. virtnet_poll wants re-enable the queue, so we disable here. > + * We synchronize against interrupts via NAPI_STATE_SCHED */ > + if (napi_schedule_prep(&vi->napi)) { > + virtqueue_disable_cb(vi->rvq); > + __napi_schedule(&vi->napi); > + } > +} > + > static void refill_work(struct work_struct *work) > { > struct virtnet_info *vi; > @@ -454,7 +468,7 @@ static void refill_work(struct work_stru > vi = container_of(work, struct virtnet_info, refill.work); > napi_disable(&vi->napi); > still_empty = !try_fill_recv(vi, GFP_KERNEL); > - napi_enable(&vi->napi); > + virtnet_napi_enable(vi); > > /* In theory, this can happen: if we don't get any buffers in > * we will *never* try to fill again. */ > @@ -638,16 +652,7 @@ static int virtnet_open(struct net_devic > { > struct virtnet_info *vi = netdev_priv(dev); > > - napi_enable(&vi->napi); > - > - /* If all buffers were filled by other side before we napi_enabled, we > - * won't get another interrupt, so process any outstanding packets > - * now. virtnet_poll wants re-enable the queue, so we disable here. > - * We synchronize against interrupts via NAPI_STATE_SCHED */ > - if (napi_schedule_prep(&vi->napi)) { > - virtqueue_disable_cb(vi->rvq); > - __napi_schedule(&vi->napi); > - } > + virtnet_napi_enable(vi); > return 0; > } > > -- > 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 -- 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
From: "Michael S. Tsirkin" <mst@redhat.com> Date: Thu, 10 Feb 2011 19:57:26 +0200 > On Thu, Feb 10, 2011 at 12:32:50PM +1030, Rusty Russell wrote: >> From: "Bruce Rogers" <brogers@novell.com> >> >> Under harsh testing conditions, including low memory, the guest would >> stop receiving packets. With this patch applied we no longer see any >> problems in the driver while performing these tests for extended periods >> of time. >> >> Make sure napi is scheduled subsequent to each napi_enable. >> >> Signed-off-by: Bruce Rogers <brogers@novell.com> >> Signed-off-by: Olaf Kirch <okir@suse.de> >> Cc: stable@kernel.org >> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> > > Rusty, so this is 2.6.38 material - you'll send this to Linus? Or DaveM? Don't worry I'll apply this to net-2.6, thanks. -- 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
From: Rusty Russell <rusty@rustcorp.com.au> Date: Thu, 10 Feb 2011 12:32:50 +1030 > From: "Bruce Rogers" <brogers@novell.com> > > Under harsh testing conditions, including low memory, the guest would > stop receiving packets. With this patch applied we no longer see any > problems in the driver while performing these tests for extended periods > of time. > > Make sure napi is scheduled subsequent to each napi_enable. > > Signed-off-by: Bruce Rogers <brogers@novell.com> > Signed-off-by: Olaf Kirch <okir@suse.de> > Cc: stable@kernel.org > Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Applied, thanks everyone. -- 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/drivers/net/virtio_net.c b/drivers/net/virtio_net.c --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -446,6 +446,20 @@ static void skb_recv_done(struct virtque } } +static void virtnet_napi_enable(struct virtnet_info *vi) +{ + napi_enable(&vi->napi); + + /* If all buffers were filled by other side before we napi_enabled, we + * won't get another interrupt, so process any outstanding packets + * now. virtnet_poll wants re-enable the queue, so we disable here. + * We synchronize against interrupts via NAPI_STATE_SCHED */ + if (napi_schedule_prep(&vi->napi)) { + virtqueue_disable_cb(vi->rvq); + __napi_schedule(&vi->napi); + } +} + static void refill_work(struct work_struct *work) { struct virtnet_info *vi; @@ -454,7 +468,7 @@ static void refill_work(struct work_stru vi = container_of(work, struct virtnet_info, refill.work); napi_disable(&vi->napi); still_empty = !try_fill_recv(vi, GFP_KERNEL); - napi_enable(&vi->napi); + virtnet_napi_enable(vi); /* In theory, this can happen: if we don't get any buffers in * we will *never* try to fill again. */ @@ -638,16 +652,7 @@ static int virtnet_open(struct net_devic { struct virtnet_info *vi = netdev_priv(dev); - napi_enable(&vi->napi); - - /* If all buffers were filled by other side before we napi_enabled, we - * won't get another interrupt, so process any outstanding packets - * now. virtnet_poll wants re-enable the queue, so we disable here. - * We synchronize against interrupts via NAPI_STATE_SCHED */ - if (napi_schedule_prep(&vi->napi)) { - virtqueue_disable_cb(vi->rvq); - __napi_schedule(&vi->napi); - } + virtnet_napi_enable(vi); return 0; }