* Re: [PATCH net] virtio-net: fix the race between channels setting and refill
2013-07-03 12:15 [PATCH net] virtio-net: fix the race between channels setting and refill Jason Wang
@ 2013-07-03 23:59 ` David Miller
2013-07-04 0:56 ` Asias He
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2013-07-03 23:59 UTC (permalink / raw)
To: jasowang; +Cc: mst, netdev, linux-kernel, virtualization, sasha.levin
From: Jason Wang <jasowang@redhat.com>
Date: Wed, 3 Jul 2013 20:15:52 +0800
> Commit 55257d72bd1c51f25106350f4983ec19f62ed1fa (virtio-net: fill only rx queues
> which are being used) tries to refill on demand when changing the number of
> channels by call try_refill_recv() directly, this may race:
>
> - the refill work who may do the refill in the same time
> - the try_refill_recv() called in bh since napi was not disabled
>
> Which may led guest complain during setting channels:
>
> virtio_net virtio0: input.1:id 0 is not a head!
>
> Solve this issue by scheduling a refill work which can guarantee the
> serialization of refill.
>
> Cc: Sasha Levin <sasha.levin@oracle.com>
> Cc: Rusty Russell <rusty@rustcorp.com.au>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
Michael, please review.
Thanks.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH net] virtio-net: fix the race between channels setting and refill
2013-07-03 12:15 [PATCH net] virtio-net: fix the race between channels setting and refill Jason Wang
2013-07-03 23:59 ` David Miller
@ 2013-07-04 0:56 ` Asias He
2013-07-04 2:18 ` Rusty Russell
2013-07-04 8:23 ` Michael S. Tsirkin
3 siblings, 0 replies; 5+ messages in thread
From: Asias He @ 2013-07-04 0:56 UTC (permalink / raw)
To: Jason Wang; +Cc: mst, netdev, linux-kernel, virtualization, Sasha Levin
On Wed, Jul 03, 2013 at 08:15:52PM +0800, Jason Wang wrote:
> Commit 55257d72bd1c51f25106350f4983ec19f62ed1fa (virtio-net: fill only rx queues
> which are being used) tries to refill on demand when changing the number of
> channels by call try_refill_recv() directly, this may race:
>
> - the refill work who may do the refill in the same time
> - the try_refill_recv() called in bh since napi was not disabled
>
> Which may led guest complain during setting channels:
>
> virtio_net virtio0: input.1:id 0 is not a head!
>
> Solve this issue by scheduling a refill work which can guarantee the
> serialization of refill.
>
> Cc: Sasha Levin <sasha.levin@oracle.com>
> Cc: Rusty Russell <rusty@rustcorp.com.au>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Asias He <asias@redhat.com>
> ---
> drivers/net/virtio_net.c | 5 +----
> 1 files changed, 1 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index c9e0038..47b4882 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -901,7 +901,6 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
> struct scatterlist sg;
> struct virtio_net_ctrl_mq s;
> struct net_device *dev = vi->dev;
> - int i;
>
> if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
> return 0;
> @@ -915,10 +914,8 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
> queue_pairs);
> return -EINVAL;
> } else {
> - for (i = vi->curr_queue_pairs; i < queue_pairs; i++)
> - if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
> - schedule_delayed_work(&vi->refill, 0);
> vi->curr_queue_pairs = queue_pairs;
> + schedule_delayed_work(&vi->refill, 0);
> }
Also, this is not on the data path, it is simpler this way.
>
> return 0;
> --
> 1.7.1
>
> _______________________________________________
> Virtualization mailing list
> Virtualization@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization
--
Asias
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH net] virtio-net: fix the race between channels setting and refill
2013-07-03 12:15 [PATCH net] virtio-net: fix the race between channels setting and refill Jason Wang
2013-07-03 23:59 ` David Miller
2013-07-04 0:56 ` Asias He
@ 2013-07-04 2:18 ` Rusty Russell
2013-07-04 8:23 ` Michael S. Tsirkin
3 siblings, 0 replies; 5+ messages in thread
From: Rusty Russell @ 2013-07-04 2:18 UTC (permalink / raw)
To: Jason Wang, mst, virtualization, netdev, linux-kernel; +Cc: Sasha Levin
Jason Wang <jasowang@redhat.com> writes:
> Commit 55257d72bd1c51f25106350f4983ec19f62ed1fa (virtio-net: fill only rx queues
> which are being used) tries to refill on demand when changing the number of
> channels by call try_refill_recv() directly, this may race:
>
> - the refill work who may do the refill in the same time
> - the try_refill_recv() called in bh since napi was not disabled
>
> Which may led guest complain during setting channels:
>
> virtio_net virtio0: input.1:id 0 is not a head!
>
> Solve this issue by scheduling a refill work which can guarantee the
> serialization of refill.
>
> Cc: Sasha Levin <sasha.levin@oracle.com>
> Cc: Rusty Russell <rusty@rustcorp.com.au>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
Thanks.
Applied,
Rusty.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net] virtio-net: fix the race between channels setting and refill
2013-07-03 12:15 [PATCH net] virtio-net: fix the race between channels setting and refill Jason Wang
` (2 preceding siblings ...)
2013-07-04 2:18 ` Rusty Russell
@ 2013-07-04 8:23 ` Michael S. Tsirkin
3 siblings, 0 replies; 5+ messages in thread
From: Michael S. Tsirkin @ 2013-07-04 8:23 UTC (permalink / raw)
To: Jason Wang; +Cc: netdev, linux-kernel, Sasha Levin, virtualization
On Wed, Jul 03, 2013 at 08:15:52PM +0800, Jason Wang wrote:
> Commit 55257d72bd1c51f25106350f4983ec19f62ed1fa (virtio-net: fill only rx queues
> which are being used) tries to refill on demand when changing the number of
> channels by call try_refill_recv() directly, this may race:
>
> - the refill work who may do the refill in the same time
> - the try_refill_recv() called in bh since napi was not disabled
>
> Which may led guest complain during setting channels:
>
> virtio_net virtio0: input.1:id 0 is not a head!
>
> Solve this issue by scheduling a refill work which can guarantee the
> serialization of refill.
>
> Cc: Sasha Levin <sasha.levin@oracle.com>
> Cc: Rusty Russell <rusty@rustcorp.com.au>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> drivers/net/virtio_net.c | 5 +----
> 1 files changed, 1 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index c9e0038..47b4882 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -901,7 +901,6 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
> struct scatterlist sg;
> struct virtio_net_ctrl_mq s;
> struct net_device *dev = vi->dev;
> - int i;
>
> if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ))
> return 0;
> @@ -915,10 +914,8 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
> queue_pairs);
> return -EINVAL;
> } else {
> - for (i = vi->curr_queue_pairs; i < queue_pairs; i++)
> - if (!try_fill_recv(&vi->rq[i], GFP_KERNEL))
> - schedule_delayed_work(&vi->refill, 0);
> vi->curr_queue_pairs = queue_pairs;
> + schedule_delayed_work(&vi->refill, 0);
> }
>
> return 0;
> --
> 1.7.1
^ permalink raw reply [flat|nested] 5+ messages in thread