Re: [GIT PULL] perf changes for v3.8
From: David Ahern
Date: Sun Dec 23 2012 - 18:17:51 EST
On 12/23/12 2:23 AM, Gleb Natapov wrote:
Your patch alone was not enough. Start here:
https://lkml.org/lkml/2012/7/12/3
I cannot reproduce this failure. I reverted 20b279ddb38c and ran "perf
record -e cycles:ppG" while guest was running. Admittedly I ran the test
for a short time, but without disabling PEBS during the guest entry this
was enough to crash a guest.
In the beginning (without any patches) VMs crashed fairly quickly. With
your patch it took longer, but I was able to consistently crash VMs. The
thread notes server info (processor, OS) and VM versions as well as load
used for the tests -- a cpu bound process (openssl), disk bound (dd) and
network (netperf).
What about forcing exclude_guest on an event that
has precise flag set without reporting error to userspace?
That's up to the perf maintainers -- Ingo, Peter, Arnaldo. Personally, I
don't like it since kernel side is changing the user request.
David
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