From: Paolo Bonzini <pbonzini@redhat.com>
To: Wang Hui <john.whui1985@gmail.com>
Cc: Gleb Natapov <gleb@redhat.com>, kvm <kvm@vger.kernel.org>
Subject: Re: [PATCH] KVM/X86: vpmu migration, make perf_event associated with vcpu thread
Date: Sat, 30 Nov 2013 12:08:49 +0100 [thread overview]
Message-ID: <5299C741.40609@redhat.com> (raw)
In-Reply-To: <5298D5FC.8030709@gmail.com>
Il 29/11/2013 18:59, Wang Hui ha scritto:
> But when I wrote a test module to make IA32_PMC1 to count the event of unhalted
> cpu-cycles, after migration the value of IA32_PMC1 never grows up again. I found
> that after migration perf_event was created exactly, but when it was created,
> "current" is qemu's main thread which won't enter no-root mode, so the count of
> perf_event will never increase.
I think the fix is to apply the MSRs in QEMU's VCPU thread, through
run_on_cpu. Interesting that I could not reproduce this when testing my
patches.
Paolo
next prev parent reply other threads:[~2013-11-30 11:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-29 17:59 [PATCH] KVM/X86: vpmu migration, make perf_event associated with vcpu thread Wang Hui
2013-11-30 10:54 ` Gleb Natapov
2013-11-30 11:42 ` Wang Hui
2013-11-30 11:08 ` Paolo Bonzini [this message]
2013-11-30 11:47 ` Wang Hui
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