Messages in this thread | | | Date | Fri, 19 Oct 2012 18:31:12 +0200 | Subject | Re: [PATCH 2/2] perf: SNB exclusive PMU access for INST_RETIRED:PREC_DIST | From | Stephane Eranian <> |
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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?
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