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Date: Mon, 02 Sep 2013 14:28:37 +0800
From: Jason Wang <jasowang@redhat.com>
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To: "Michael S. Tsirkin" <mst@redhat.com>
CC: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V2 2/6] vhost_net: use vhost_add_used_and_signal_n() in
 vhost_zerocopy_signal_used()
References: <1377836962-49780-1-git-send-email-jasowang@redhat.com> <1377836962-49780-3-git-send-email-jasowang@redhat.com> <20130902055048.GA19838@redhat.com>
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On 09/02/2013 01:50 PM, Michael S. Tsirkin wrote:
> On Fri, Aug 30, 2013 at 12:29:18PM +0800, Jason Wang wrote:
>> > We tend to batch the used adding and signaling in vhost_zerocopy_callback()
>> > which may result more than 100 used buffers to be updated in
>> > vhost_zerocopy_signal_used() in some cases. So wwitch to use
> switch

Ok.
>> > vhost_add_used_and_signal_n() to avoid multiple calls to
>> > vhost_add_used_and_signal(). Which means much more less times of used index
>> > updating and memory barriers.
> pls put info on perf gain in commit log too
>

Sure.