From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Rob Landley <rob@landley.net>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, Arnd Bergmann <arnd@arndb.de>,
David Howells <dhowells@redhat.com>,
Akinobu Mita <akinobu.mita@gmail.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Herbert Xu <herbert@gondor.hengli.com.au>,
Stephen Rothwell <sfr@canb.auug.org.au>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arch@vger.kernel.org, Gleb Natapov <gleb@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, Avi Kivity <avi@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH] bitops: add _local bitops
Date: Fri, 11 May 2012 09:02:34 +1000 [thread overview]
Message-ID: <1336690954.3881.66.camel@pasglop> (raw)
In-Reply-To: <4FAACF1C.2060504@zytor.com>
On Wed, 2012-05-09 at 13:10 -0700, H. Peter Anvin wrote:
> On 05/09/2012 01:07 PM, Michael S. Tsirkin wrote:
> >
> > In practice ATM any of the above will work. We probably don't even need
> > to add barrier() calls since what we do afterwards is apic access which
> > has an optimization barrier anyway. But I'm fine with adding them in
> > there just in case if that's what people want.
> >
>
> If you have the optimization barrier anyway, then I'd be fine with you
> just using __test_and_clear_bit() and add to a comment in
> arch/x86/include/asm/bitops.h that KVM needs it to be locally atomic.
>
>
What is it used for ? IE. Is this strictly a requirement of x86 KVM ?
Cheers,
Ben.
next prev parent reply other threads:[~2012-05-10 23:03 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-09 13:45 [PATCH] bitops: add _local bitops Michael S. Tsirkin
2012-05-09 13:45 ` Michael S. Tsirkin
2012-05-09 14:03 ` H. Peter Anvin
2012-05-09 14:03 ` H. Peter Anvin
2012-05-09 15:06 ` Michael S. Tsirkin
2012-05-09 15:06 ` Michael S. Tsirkin
2012-05-09 15:43 ` Michael S. Tsirkin
2012-05-09 15:43 ` Michael S. Tsirkin
2012-05-09 15:44 ` H. Peter Anvin
2012-05-09 15:44 ` H. Peter Anvin
2012-05-09 15:47 ` Michael S. Tsirkin
2012-05-09 15:47 ` Michael S. Tsirkin
2012-05-09 16:24 ` H. Peter Anvin
2012-05-09 16:24 ` H. Peter Anvin
2012-05-09 16:36 ` Michael S. Tsirkin
2012-05-09 16:45 ` H. Peter Anvin
2012-05-09 16:45 ` H. Peter Anvin
2012-05-09 16:55 ` Michael S. Tsirkin
2012-05-09 16:55 ` Michael S. Tsirkin
2012-05-09 14:06 ` Arnd Bergmann
2012-05-09 14:06 ` Arnd Bergmann
2012-05-09 14:17 ` Avi Kivity
2012-05-09 19:19 ` Andrew Morton
2012-05-09 19:23 ` H. Peter Anvin
2012-05-09 19:23 ` H. Peter Anvin
2012-05-09 20:07 ` Michael S. Tsirkin
2012-05-09 20:10 ` H. Peter Anvin
2012-05-09 20:10 ` H. Peter Anvin
2012-05-09 20:12 ` Michael S. Tsirkin
2012-05-09 20:12 ` Michael S. Tsirkin
2012-05-10 9:26 ` Avi Kivity
2012-05-10 23:02 ` Benjamin Herrenschmidt [this message]
2012-05-10 17:38 ` Rob Landley
2012-05-10 17:38 ` Rob Landley
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