From: Rusty Russell Date: Thu, 29 Dec 2011 00:43:15 +0000 (+0000) Subject: virtio_net: use non-reentrant workqueue. X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f1776dade17cd54562f4bc1d01de89c4908b4dd0;p=linux-beck.git virtio_net: use non-reentrant workqueue. Michael S. Tsirkin also noticed that we could run the refill work multiple CPUs: if we kick off a refill on one CPU and then on another, they would both manipulate the queue at the same time (they use napi_disable to avoid racing against the receive handler itself). Tejun points out that this is what the WQ_NON_REENTRANT flag is for, and that there is a convenient system kthread we can use. Signed-off-by: Rusty Russell Signed-off-by: David S. Miller --- diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 07ca150a5ca6..2055386eda58 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -508,7 +508,7 @@ static void refill_work(struct work_struct *work) /* In theory, this can happen: if we don't get any buffers in * we will *never* try to fill again. */ if (still_empty) - schedule_delayed_work(&vi->refill, HZ/2); + queue_delayed_work(system_nrt_wq, &vi->refill, HZ/2); } static int virtnet_poll(struct napi_struct *napi, int budget) @@ -527,7 +527,7 @@ again: if (vi->num < vi->max / 2) { if (!try_fill_recv(vi, GFP_ATOMIC)) - schedule_delayed_work(&vi->refill, 0); + queue_delayed_work(system_nrt_wq, &vi->refill, 0); } /* Out of packets? */ @@ -729,7 +729,7 @@ static int virtnet_open(struct net_device *dev) /* Make sure we have some buffers: if oom use wq. */ if (!try_fill_recv(vi, GFP_KERNEL)) - schedule_delayed_work(&vi->refill, 0); + queue_delayed_work(system_nrt_wq, &vi->refill, 0); virtnet_napi_enable(vi); return 0;