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Date: Mon, 14 Mar 2016 21:18:26 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        xen-devel <Xen-devel@lists.xen.org>,
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        Borislav Petkov <bp@alien8.de>, X86 ML <x86@kernel.org>,
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        KVM list <kvm@vger.kernel.org>, Andy Lutomirski <luto@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 2/5] x86/msr: Carry on after a non-"safe" MSR access
 fails without !panic_on_oops
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On Mon, Mar 14, 2016 at 11:10:16AM -0700, Andy Lutomirski wrote:
> A couple of the wrmsr users actually care about performance.  These
> are the ones involved in context switching and, to a lesser extent, in
> switching in and out of guest mode.

Right, this very much includes a number of perf MSRs. Some of those get
called from the context switch path, others from the NMI handler.