From: Vince Weaver <vincent.weaver@maine.edu>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: Re: perf: rdpmc bug when viewing all procs on remote cpu
Date: Thu, 10 Jan 2019 12:50:53 -0500 (EST) [thread overview]
Message-ID: <alpine.DEB.2.21.1901101246340.3358@macbook-air> (raw)
In-Reply-To: <alpine.DEB.2.21.1901101229010.3358@macbook-air>
On Thu, 10 Jan 2019, Vince Weaver wrote:
> However if you create an all-process attached to CPU event:
> perf_event_open(attr, -1, X, -1, 0);
> the mmap event index is set as if this were a valid event and so the rdpmc
> succeeds even though it shouldn't (we're trying to read an event value
> on a remote cpu with a local rdpmc).
For a test case, try the
tests/rdpmc/rdpmc_attach_other_cpu
test found in my perf_event_tests suite
git clone https://github.com/deater/perf_event_tests
I can trigger it with current git on an intel machine, but not on an AMD
machine. Possibly because it is defaulting to one of the fixed counter
slots?
Vince
next prev parent reply other threads:[~2019-01-10 17:50 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-10 17:35 Vince Weaver
2019-01-10 17:50 ` Vince Weaver [this message]
2019-01-10 20:00 ` Vince Weaver
2019-01-11 21:52 ` Vince Weaver
2019-01-18 12:01 ` Peter Zijlstra
2019-01-18 14:09 ` Vince Weaver
2019-01-18 15:58 ` Peter Zijlstra
2019-01-18 17:24 ` Vince Weaver
2019-01-18 20:10 ` Peter Zijlstra
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