Michael S. Tsirkin
2023-Apr-28 01:09 UTC
[PATCH v2] virtio_net: suppress cpu stall when free_unused_bufs
On Thu, Apr 27, 2023 at 06:46:18PM +0800, Wenliang Wang wrote:> For multi-queue and large ring-size use case, the following error > occurred when free_unused_bufs: > rcu: INFO: rcu_sched self-detected stall on CPU. > > Signed-off-by: Wenliang Wang <wangwenliang.1995 at bytedance.com>pls send vN+1 as a new thread not as a reply in existing thread of vN.> --- > v2: > -add need_resched check. > -apply same logic to sq. > --- > drivers/net/virtio_net.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index ea1bd4bb326d..573558b69a60 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -3559,12 +3559,16 @@ static void free_unused_bufs(struct virtnet_info *vi) > struct virtqueue *vq = vi->sq[i].vq; > while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) > virtnet_sq_free_unused_buf(vq, buf); > + if (need_resched()) > + schedule(); > } > > for (i = 0; i < vi->max_queue_pairs; i++) { > struct virtqueue *vq = vi->rq[i].vq; > while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) > virtnet_rq_free_unused_buf(vq, buf); > + if (need_resched()) > + schedule(); > } > } > > -- > 2.20.1