[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers |
Date: |
Fri, 2 Sep 2011 18:57:48 +0300 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Fri, Sep 02, 2011 at 08:11:29AM +0200, Paolo Bonzini wrote:
> On 09/02/2011 02:11 AM, David Gibson wrote:
> >>>> >Why not limit the change to ppc then?
> >>>
> >>> Because the bug is masked by the x86 memory model, but it is still
> >>> there even there conceptually. It is not really true that x86 does
> >>> not need memory barriers, though it doesn't in this case:
> >>>
> >>>
> >>> http://bartoszmilewski.wordpress.com/2008/11/05/who-ordered-memory-fences-on-an-x86/
> >Not to mention that pcc is not the only non-x86 architecture. I don't
> >know all their storage models off hand, but the point is that there is
> >a required order to these writes, so there should be a memory barrier.
>
> Indeed, I interpreted Michael's question more as "why not limit the
> change to non-x86". I think we should cater to all memory models
> except perhaps the Alpha's.
>
> Paolo
Yes, x86 is pretty popular.
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, (continued)
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, Paolo Bonzini, 2011/09/06
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, David Gibson, 2011/09/06
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, Avi Kivity, 2011/09/06
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, Michael S. Tsirkin, 2011/09/06
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, Paolo Bonzini, 2011/09/06
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, Paolo Bonzini, 2011/09/05
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, Michael S. Tsirkin, 2011/09/05
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, Paolo Bonzini, 2011/09/05
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, David Gibson, 2011/09/01
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers, Paolo Bonzini, 2011/09/02
- Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers,
Michael S. Tsirkin <=