From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 08/13] xen/pvticketlock: disable interrupts while blocking
Date: Wed, 07 Sep 2011 20:41:48 +0300
Message-ID: <4E67ACDC.90303@redhat.com>
References: <20110906151408.GA7459@redhat.com> <4E66615E.8070806@goop.org> <20110906182758.GR5795@redhat.com> <4E66EF86.9070200@redhat.com> <20110907134411.GV5795@redhat.com> <4E678992.5050709@redhat.com> <20110907155657.GX5795@redhat.com> <4E679AF4.50209@redhat.com> <20110907165203.GQ6838@redhat.com> <4E67A551.4000502@redhat.com> <20110907172117.GY5795@redhat.com>
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To: Don Zickus <dzickus@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>, Peter Zijlstra <peterz@infradead.org>, "H. Peter Anvin" <hpa@zytor.com>, Linus Torvalds <torvalds@linux-foundation.org>, Ingo Molnar <mingo@elte.hu>, the arch/x86 maintainers <x86@kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Nick Piggin <npiggin@kernel.dk>, Marcelo Tosatti <mtosatti@redhat.com>, KVM <kvm@vger.kernel.org>, Andi Kleen <andi@firstfloor.org>, Xen Devel <xen-devel@lists.xensource.com>, Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>
List-Id: xen-devel@lists.xenproject.org

On 09/07/2011 08:21 PM, Don Zickus wrote:
> >
> >  How about, during NMI, save %rip to a per-cpu variable.  Handle just
> >  one cause.  If, on the next NMI, we hit the same %rip, assume
> >  back-to-back NMI has occured and now handle all causes.
>
> I had a similar idea a couple of months ago while debugging a continuous
> flow of back-to-back NMIs from a stress-test perf application and I
> couldn't get it to work.  But let me try it again, because it does make
> sense as an optimization.
>
>

Great, thanks.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.