Qi Zheng wrote: > > > On 2023/4/27 16:23, Michael S. Tsirkin wrote: > > On Thu, Apr 27, 2023 at 04:13:45PM +0800, Xuan Zhuo wrote: > >> On Thu, 27 Apr 2023 04:12:44 -0400, "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > >>> On Thu, Apr 27, 2023 at 03:13:44PM +0800, Xuan Zhuo wrote: > >>>> On Thu, 27 Apr 2023 15:02:26 +0800, Wenliang Wang <wangwenliang.1995@xxxxxxxxxxxxx> wrote: > >>>>> > >>>>> > >>>>> On 4/27/23 2:20 PM, Xuan Zhuo wrote: > >>>>>> On Thu, 27 Apr 2023 12:34:33 +0800, Wenliang Wang <wangwenliang.1995@xxxxxxxxxxxxx> wrote: > >>>>>>> For multi-queue and large rx-ring-size use case, the following error > >>>>>> > >>>>>> Cound you give we one number for example? > >>>>> > >>>>> 128 queues and 16K queue_size is typical. > >>>>> > >>>>>> > >>>>>>> occurred when free_unused_bufs: > >>>>>>> rcu: INFO: rcu_sched self-detected stall on CPU. > >>>>>>> > >>>>>>> Signed-off-by: Wenliang Wang <wangwenliang.1995@xxxxxxxxxxxxx> > >>>>>>> --- > >>>>>>> drivers/net/virtio_net.c | 1 + > >>>>>>> 1 file changed, 1 insertion(+) > >>>>>>> > >>>>>>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > >>>>>>> index ea1bd4bb326d..21d8382fd2c7 100644 > >>>>>>> --- a/drivers/net/virtio_net.c > >>>>>>> +++ b/drivers/net/virtio_net.c > >>>>>>> @@ -3565,6 +3565,7 @@ static void free_unused_bufs(struct virtnet_info *vi) > >>>>>>> struct virtqueue *vq = vi->rq[i].vq; > >>>>>>> while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) > >>>>>>> virtnet_rq_free_unused_buf(vq, buf); > >>>>>>> + schedule(); > >>>>>> > >>>>>> Just for rq? > >>>>>> > >>>>>> Do we need to do the same thing for sq? > >>>>> Rq buffers are pre-allocated, take seconds to free rq unused buffers. > >>>>> > >>>>> Sq unused buffers are much less, so do the same for sq is optional. > >>>> > >>>> I got. > >>>> > >>>> I think we should look for a way, compatible with the less queues or the smaller > >>>> rings. Calling schedule() directly may be not a good way. > >>>> > >>>> Thanks. > >>> > >>> Why isn't it a good way? > >> > >> For the small ring, I don't think it is a good way, maybe we only deal with one > >> buf, then call schedule(). > >> > >> We can call the schedule() after processing a certain number of buffers, > >> or check need_resched () first. > >> > >> Thanks. > > > > > > Wenliang, does > > if (need_resched()) > > schedule(); > > Can we just use cond_resched()? I believe that is preferred. But v2 still calls schedule directly. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
