Thread (19 messages) 19 messages, 6 authors, 2021-12-03

Re: [PATCH 2/6] vhost_net: get rid of vhost_net_flush_vq() and extra flush calls

From: Stefano Garzarella <sgarzare@redhat.com>
Date: 2021-11-16 14:34:51
Also in: kvm, lkml, virtualization

On Mon, Nov 15, 2021 at 06:29:59PM +0300, Andrey Ryabinin wrote:
quoted hunk ↗ jump to hunk
vhost_net_flush_vq() calls vhost_work_dev_flush() twice passing
vhost_dev pointer obtained via 'n->poll[index].dev' and
'n->vqs[index].vq.poll.dev'. This is actually the same pointer,
initialized in vhost_net_open()/vhost_dev_init()/vhost_poll_init()

Remove vhost_net_flush_vq() and call vhost_work_dev_flush() directly.
Do the flushes only once instead of several flush calls in a row
which seems rather useless.

Signed-off-by: Andrey Ryabinin <redacted>
---
drivers/vhost/net.c   | 11 ++---------
drivers/vhost/vhost.h |  1 +
2 files changed, 3 insertions(+), 9 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 11221f6d11b8..b1feb5e0571e 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1373,16 +1373,9 @@ static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
	*rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq);
}

-static void vhost_net_flush_vq(struct vhost_net *n, int index)
-{
-	vhost_work_dev_flush(n->poll[index].dev);
-	vhost_work_dev_flush(n->vqs[index].vq.poll.dev);
-}
-
static void vhost_net_flush(struct vhost_net *n)
{
-	vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
-	vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
+	vhost_work_dev_flush(&n->dev);
	if (n->vqs[VHOST_NET_VQ_TX].ubufs) {
		mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
		n->tx_flush = true;
@@ -1572,7 +1565,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
	}

	if (oldsock) {
-		vhost_net_flush_vq(n, index);
+		vhost_work_dev_flush(&n->dev);
		sockfd_put(oldsock);
	}
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 638bb640d6b4..ecbaa5c6005f 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -15,6 +15,7 @@
#include <linux/vhost_iotlb.h>
#include <linux/irqbypass.h>

+struct vhost_dev;
Is this change needed?

Stefano
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help