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References: <20240328002149.1141302-1-gshan@redhat.com> <20240328002149.1141302-4-gshan@redhat.com>
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From: Jason Wang <jasowang@redhat.com>
Date: Thu, 28 Mar 2024 11:54:56 +0800
Message-ID: <CACGkMEt5fz9mhZ4YK=Oe+n0kx0YKe4hOnGvVQwh-w4rSfs7uRg@mail.gmail.com>
Subject: Re: [PATCH v3 3/3] vhost: Improve vhost_get_avail_idx() with smp_rmb()
To: Gavin Shan <gshan@redhat.com>
Cc: virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, 
	mst@redhat.com, will@kernel.org, davem@davemloft.net, stefanha@redhat.com, 
	sgarzare@redhat.com, keirf@google.com, yihyu@redhat.com, shan.gavin@gmail.com
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On Thu, Mar 28, 2024 at 8:22=E2=80=AFAM Gavin Shan <gshan@redhat.com> wrote=
:
>
> All the callers of vhost_get_avail_idx() are concerned to the memory
> barrier, imposed by smp_rmb() to ensure the order of the available
> ring entry read and avail_idx read.
>
> Improve vhost_get_avail_idx() so that smp_rmb() is executed when
> the avail_idx is advanced. With it, the callers needn't to worry
> about the memory barrier.
>
> Suggested-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Gavin Shan <gshan@redhat.com>

Acked-by: Jason Wang <jasowang@redhat.com>

Thanks