From: Peter Zijlstra <peterz@infradead.org>
To: Stephane Eranian <eranian@google.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
"mingo@elte.hu" <mingo@elte.hu>,
"ak@linux.intel.com" <ak@linux.intel.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Jiri Olsa <jolsa@redhat.com>
Subject: Re: [PATCH 2/2] perf: SNB exclusive PMU access for INST_RETIRED:PREC_DIST
Date: Fri, 19 Oct 2012 18:45:52 +0200 [thread overview]
Message-ID: <1350665152.2768.41.camel@twins> (raw)
In-Reply-To: <CABPqkBQ5kCyGByFS-D62RYg2VUf_W-rJKDH=AzyrcaBPVY-eFQ@mail.gmail.com>
On Fri, 2012-10-19 at 18:31 +0200, Stephane Eranian wrote:
> On Fri, Oct 19, 2012 at 6:27 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Fri, 2012-10-19 at 16:52 +0200, Stephane Eranian wrote:
> >> +static int intel_pebs_aliases_snb(struct perf_event *event)
> >> +{
> >> + u64 cfg = event->hw.config;
> >> + /*
> >> + * for INST_RETIRED.PREC_DIST to work correctly with PEBS, it must
> >> + * be measured alone on SNB (exclusive PMU access) as per Intel SDM.
> >> + */
> >> + if ((cfg & INTEL_ARCH_EVENT_MASK) == 0x01c0 && !event->attr.exclusive) {
> >> + pr_info("perf: INST_RETIRED.PREC_DIST only works in exclusive mode\n");
> >> + return -EINVAL;
> >
> > This isn't limited to admin, right? So the above turns into a DoS on the
> > console.
> >
> Ok, so how about a WARN_ON_ONCE() instead?
That should be fine I guess ;-)
next prev parent reply other threads:[~2012-10-19 16:46 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-19 14:52 [PATCH 0/2] perf: enforce exclusive PMU access for SNB INST_RETIRED:PREC_DIST Stephane Eranian
2012-10-19 14:52 ` [PATCH 1/2] perf tools: add event modifier to request exclusive PMU access Stephane Eranian
2012-10-19 15:13 ` Peter Zijlstra
2012-10-19 15:17 ` Stephane Eranian
2012-10-19 15:23 ` Jiri Olsa
2012-10-19 15:47 ` Stephane Eranian
2012-10-19 15:53 ` Jiri Olsa
2012-10-19 15:58 ` Stephane Eranian
2012-10-19 15:46 ` Andi Kleen
2012-10-19 16:07 ` Jiri Olsa
2012-10-19 14:52 ` [PATCH 2/2] perf: SNB exclusive PMU access for INST_RETIRED:PREC_DIST Stephane Eranian
2012-10-19 15:49 ` Andi Kleen
2012-10-19 15:58 ` Stephane Eranian
2012-10-19 16:27 ` Peter Zijlstra
2012-10-19 16:31 ` Stephane Eranian
2012-10-19 16:45 ` Peter Zijlstra [this message]
2012-10-19 17:20 ` Andi Kleen
2012-10-21 16:55 ` Ingo Molnar
2012-10-21 17:54 ` Stephane Eranian
2012-10-21 18:03 ` Ingo Molnar
2012-10-22 11:31 ` Stephane Eranian
2012-10-24 8:15 ` Ingo Molnar
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