From: Avi Kivity <avi@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
kvm@vger.kernel.org, virtualization@lists.osdl.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
David Miller <davem@davemloft.net>
Subject: Re: [PATCH] vhost-net: switch to smp barriers
Date: Sun, 07 Feb 2010 11:56:14 +0200 [thread overview]
Message-ID: <4B6E8E3E.30705@redhat.com> (raw)
In-Reply-To: <20100207094441.GA20271@redhat.com>
On 02/07/2010 11:44 AM, Michael S. Tsirkin wrote:
> On Sun, Feb 07, 2010 at 11:42:29AM +0200, Avi Kivity wrote:
>
>> On 02/01/2010 07:21 PM, Michael S. Tsirkin wrote:
>>
>>> vhost-net only uses memory barriers to control SMP effects
>>> (communication with userspace potentially running on a different CPU),
>>> so it should use SMP barriers and not mandatory barriers for memory
>>> access ordering, as suggested by Documentation/memory-barriers.txt
>>>
>>>
>>>
>> A UP guest running on an SMP host still needs those barriers.
>>
> Correct. And since vhost net is running host-side, smp_XX
> barriers will do exactly the right thing, right?
>
Right, of course. Mixed up virtio and vhost.
--
error compiling committee.c: too many arguments to function
prev parent reply other threads:[~2010-02-07 9:56 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-01 17:21 [PATCH] vhost-net: switch to smp barriers Michael S. Tsirkin
2010-02-01 17:21 ` Michael S. Tsirkin
2010-02-01 17:21 ` Michael S. Tsirkin
2010-02-07 9:07 ` Michael S. Tsirkin
2010-02-08 8:19 ` Rusty Russell
2010-02-13 17:39 ` Michael S. Tsirkin
2010-02-14 19:55 ` David Miller
2010-02-07 9:42 ` Avi Kivity
2010-02-07 9:44 ` Michael S. Tsirkin
2010-02-07 9:56 ` Avi Kivity [this message]
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