Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCHv4 2/2] vhost_net: a kernel-level virtio server | Date | Thu, 27 Aug 2009 20:40:02 +0930 |
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On Thu, 27 Aug 2009 08:15:18 pm Michael S. Tsirkin wrote: > On Tue, Aug 25, 2009 at 09:40:40PM +0930, Rusty Russell wrote: > > Also, see other fixes to the lguest launcher since then which might > > be relevant to this code: > > lguest: get more serious about wmb() in example Launcher code > > Heh, this just gets one step closer to a real wmb. I just used the > correct code from linux, so I think nothing needs to be done in vhost. > Apropos this change in lguest: why is a compiler barrier sufficient? The > comment says devices are run in separate threads (presumably from > guest?), if so don't you need to tell CPU that there's a barrier as > well?
Yep, but x86 only :) The kernel uses a real insn if XMM/XMM2, but I don't know if userspace needs that. I just use compiler barriers.
Thanks, Rusty.
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