From: Rusty Russell <rusty@rustcorp•com.au>
To: netdev <netdev@vger•kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat•com>, Tejun Heo <tj@kernel•org>
Subject: [PATCH] virtio_net: use non-reentrant workqueue.
Date: Thu, 29 Dec 2011 21:13:15 +1030 [thread overview]
Message-ID: <87mxabfykc.fsf@rustcorp.com.au> (raw)
In-Reply-To: 87ehvogitg.fsf@rustcorp.com.au
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 <rusty@rustcorp•com.au>
---
drivers/net/virtio_net.c | 6 +++---
1 file changed, 3 insertions(+), 3 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
@@ -507,7 +507,7 @@ static void refill_work(struct work_stru
/* 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)
@@ -526,7 +526,7 @@ 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? */
@@ -727,7 +727,7 @@ static int virtnet_open(struct net_devic
/* 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;
next parent reply other threads:[~2011-12-29 10:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87ehvogitg.fsf@rustcorp.com.au>
2011-12-29 10:43 ` Rusty Russell [this message]
2011-12-29 20:33 ` [PATCH] virtio_net: use non-reentrant workqueue Michael S. Tsirkin
2011-12-29 21:44 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87mxabfykc.fsf@rustcorp.com.au \
--to=rusty@rustcorp$(echo .)com.au \
--cc=mst@redhat$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=tj@kernel$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox