From: "Michael S. Tsirkin" <mst@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: aik@ozlabs.ru, aliguori@us.ibm.com, rusty@rustcorp.com.au,
qemu-devel@nongnu.org, agraf@suse.de
Subject: Re: [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers
Date: Fri, 2 Sep 2011 18:57:48 +0300 [thread overview]
Message-ID: <20110902155748.GB18389@redhat.com> (raw)
In-Reply-To: <4E607391.9070804@redhat.com>
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.
prev parent reply other threads:[~2011-09-02 16:01 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-01 6:09 [Qemu-devel] [PATCH] virtio: Make memory barriers be memory barriers David Gibson
2011-09-01 6:47 ` Paolo Bonzini
2011-09-02 0:08 ` David Gibson
2011-09-02 6:49 ` Paolo Bonzini
2011-09-03 11:53 ` Blue Swirl
2011-09-01 7:37 ` Sasha Levin
2011-09-01 7:38 ` Sasha Levin
2011-09-01 7:56 ` Paolo Bonzini
2011-09-02 0:09 ` David Gibson
2011-09-01 15:30 ` Michael S. Tsirkin
2011-09-01 16:14 ` Paolo Bonzini
2011-09-01 16:34 ` Michael S. Tsirkin
2011-09-01 20:31 ` Paolo Bonzini
2011-09-02 15:45 ` Michael S. Tsirkin
2011-09-03 14:46 ` David Gibson
2011-09-04 9:16 ` Michael S. Tsirkin
2011-09-05 4:43 ` David Gibson
2011-09-05 9:19 ` Michael S. Tsirkin
2011-09-06 3:12 ` David Gibson
2011-09-06 6:55 ` Paolo Bonzini
2011-09-06 9:02 ` David Gibson
2011-09-06 9:28 ` Avi Kivity
2011-09-06 9:35 ` Michael S. Tsirkin
2011-09-06 9:38 ` Paolo Bonzini
2011-09-05 7:41 ` Paolo Bonzini
2011-09-05 8:06 ` Michael S. Tsirkin
2011-09-05 9:42 ` Paolo Bonzini
2011-09-03 16:19 ` Paolo Bonzini
2011-09-04 8:47 ` Michael S. Tsirkin
2011-09-02 0:11 ` David Gibson
2011-09-02 6:11 ` Paolo Bonzini
2011-09-02 15:57 ` Michael S. Tsirkin [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110902155748.GB18389@redhat.com \
--to=mst@redhat.com \
--cc=agraf@suse.de \
--cc=aik@ozlabs.ru \
--cc=aliguori@us.ibm.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=rusty@rustcorp.com.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).