From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com, xuanzhuo@linux.alibaba.com
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
alvaro.karsz@solid-run.com, maxime.coquelin@redhat.com
Subject: [PATCH net-next v4 2/2] virtio-net: add cond_resched() to the command waiting loop
Date: Thu, 20 Jul 2023 04:38:39 -0400 [thread overview]
Message-ID: <20230720083839.481487-3-jasowang@redhat.com> (raw)
In-Reply-To: <20230720083839.481487-1-jasowang@redhat.com>
Adding cond_resched() to the command waiting loop for a better
co-operation with the scheduler. This allows to give CPU a breath to
run other task(workqueue) instead of busy looping when preemption is
not allowed on a device whose CVQ might be slow.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/virtio_net.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 9f3b1d6ac33d..e7533f29b219 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2314,8 +2314,10 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
* into the hypervisor, so the request should be handled immediately.
*/
while (!virtqueue_get_buf(vi->cvq, &tmp) &&
- !virtqueue_is_broken(vi->cvq))
+ !virtqueue_is_broken(vi->cvq)) {
+ cond_resched();
cpu_relax();
+ }
return vi->ctrl->status == VIRTIO_NET_OK;
}
--
2.39.3
next prev parent reply other threads:[~2023-07-20 8:38 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-20 8:38 [PATCH net-next v4 0/2] virtio-net: don't busy poll for cvq command Jason Wang
2023-07-20 8:38 ` [PATCH net-next v4 1/2] virtio-net: convert rx mode setting to use workqueue Jason Wang
2023-07-20 20:25 ` Shannon Nelson
2023-07-20 8:38 ` Jason Wang [this message]
2023-07-20 15:31 ` [PATCH net-next v4 2/2] virtio-net: add cond_resched() to the command waiting loop Shannon Nelson
2023-07-20 20:58 ` Michael S. Tsirkin
2023-07-20 20:26 ` Shannon Nelson
2023-07-20 21:02 ` Michael S. Tsirkin
2023-07-21 14:37 ` Maxime Coquelin
2023-07-21 14:45 ` Michael S. Tsirkin
2023-07-21 14:58 ` Maxime Coquelin
2023-07-21 15:10 ` Michael S. Tsirkin
2023-07-21 20:18 ` Maxime Coquelin
2023-07-24 6:46 ` Michael S. Tsirkin
2023-07-24 6:52 ` Jason Wang
2023-07-24 7:18 ` Michael S. Tsirkin
2023-07-25 3:03 ` Jason Wang
2024-02-22 19:21 ` Michael S. Tsirkin
2024-02-26 5:08 ` Jason Wang
2023-10-05 19:35 ` Feng Liu
2023-10-08 5:27 ` Jason Wang
2023-07-24 6:52 ` Jason Wang
2023-07-24 7:17 ` Michael S. Tsirkin
2023-07-25 3:07 ` Jason Wang
2023-07-25 7:36 ` Michael S. Tsirkin
2023-07-26 1:55 ` Jason Wang
2023-07-26 11:37 ` Michael S. Tsirkin
2023-07-27 6:03 ` Jason Wang
2023-07-27 6:10 ` Michael S. Tsirkin
2023-07-27 8:59 ` Jason Wang
2023-07-27 9:46 ` Michael S. Tsirkin
2023-07-31 6:30 ` Jason Wang
2023-08-08 2:30 ` Jason Wang
2023-08-10 19:41 ` Michael S. Tsirkin
2023-08-11 2:23 ` Jason Wang
2023-08-11 5:42 ` Michael S. Tsirkin
2023-08-11 9:18 ` Jason Wang
2023-08-11 9:21 ` Michael S. Tsirkin
2023-08-11 9:43 ` Jason Wang
2023-08-11 9:51 ` Michael S. Tsirkin
2023-08-11 9:54 ` Jason Wang
2023-08-11 10:12 ` Michael S. Tsirkin
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