From: Stefan Hajnoczi <stefanha@gmail.com>
To: Jason Wang <jasowang@redhat.com>
Cc: mst@redhat.com, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next V2 1/3] vhost: better detection of available buffers
Date: Tue, 3 Jan 2017 13:08:30 +0000 [thread overview]
Message-ID: <20170103130830.GA14707@stefanha-x1.localdomain> (raw)
In-Reply-To: <1482912571-3157-2-git-send-email-jasowang@redhat.com>
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On Wed, Dec 28, 2016 at 04:09:29PM +0800, Jason Wang wrote:
> This patch tries to do several tweaks on vhost_vq_avail_empty() for a
> better performance:
>
> - check cached avail index first which could avoid userspace memory access.
> - using unlikely() for the failure of userspace access
> - check vq->last_avail_idx instead of cached avail index as the last
> step.
>
> This patch is need for batching supports which needs to peek whether
> or not there's still available buffers in the ring.
>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> drivers/vhost/vhost.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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next prev parent reply other threads:[~2017-01-03 13:08 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-28 8:09 [PATCH net-next V2 0/3] vhost net tx batching Jason Wang
2016-12-28 8:09 ` [PATCH net-next V2 1/3] vhost: better detection of available buffers Jason Wang
2017-01-03 13:08 ` Stefan Hajnoczi [this message]
2016-12-28 8:09 ` [PATCH net-next V2 2/3] vhost_net: tx batching Jason Wang
2017-01-03 13:16 ` Stefan Hajnoczi
2016-12-28 8:09 ` [PATCH net-next V2 3/3] tun: rx batching Jason Wang
2016-12-29 16:35 ` David Miller
2016-12-30 5:14 ` Jason Wang
2017-01-03 13:33 ` Stefan Hajnoczi
2017-01-04 3:03 ` Jason Wang
2017-01-05 9:27 ` Stefan Hajnoczi
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