[RFC PATCH v1] vsock/loopback: don't disable irqs for queue access

Arseniy Krasnov posted 1 patch 2 years, 10 months ago
There is a newer version of this series
net/vmw_vsock/vsock_loopback.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
[RFC PATCH v1] vsock/loopback: don't disable irqs for queue access
Posted by Arseniy Krasnov 2 years, 10 months ago
This replaces 'skb_queue_tail()' with 'virtio_vsock_skb_queue_tail()'.
The first one uses 'spin_lock_irqsave()', second uses 'spin_lock_bh()'.
There is no need to disable interrupts in the loopback transport as
there is no access to the queue with skbs from interrupt context. Both
virtio and vhost transports work in the same way.

Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
---
 net/vmw_vsock/vsock_loopback.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index e3afc0c866f5..5c6360df1f31 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c
@@ -31,8 +31,7 @@ static int vsock_loopback_send_pkt(struct sk_buff *skb)
 	struct vsock_loopback *vsock = &the_vsock_loopback;
 	int len = skb->len;
 
-	skb_queue_tail(&vsock->pkt_queue, skb);
-
+	virtio_vsock_skb_queue_tail(&vsock->pkt_queue, skb);
 	queue_work(vsock->workqueue, &vsock->pkt_work);
 
 	return len;
-- 
2.25.1
Re: [RFC PATCH v1] vsock/loopback: don't disable irqs for queue access
Posted by Stefano Garzarella 2 years, 10 months ago
On Sun, Apr 09, 2023 at 10:17:51PM +0300, Arseniy Krasnov wrote:
>This replaces 'skb_queue_tail()' with 'virtio_vsock_skb_queue_tail()'.
>The first one uses 'spin_lock_irqsave()', second uses 'spin_lock_bh()'.
>There is no need to disable interrupts in the loopback transport as
>there is no access to the queue with skbs from interrupt context. Both
>virtio and vhost transports work in the same way.

Yep, this is a good point!

>
>Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
>---
> net/vmw_vsock/vsock_loopback.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)

LGTM! (net-next material)

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Thanks,
Stefano

>
>diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
>index e3afc0c866f5..5c6360df1f31 100644
>--- a/net/vmw_vsock/vsock_loopback.c
>+++ b/net/vmw_vsock/vsock_loopback.c
>@@ -31,8 +31,7 @@ static int vsock_loopback_send_pkt(struct sk_buff *skb)
> 	struct vsock_loopback *vsock = &the_vsock_loopback;
> 	int len = skb->len;
>
>-	skb_queue_tail(&vsock->pkt_queue, skb);
>-
>+	virtio_vsock_skb_queue_tail(&vsock->pkt_queue, skb);
> 	queue_work(vsock->workqueue, &vsock->pkt_work);
>
> 	return len;
>-- 
>2.25.1
>