Commit dc89e75a authored May 09, 2016 by Vineet Gupta Committed by Ingo Molnar Jun 03, 2016

tools/perf: Handle -EOPNOTSUPP for sampling events



This allows (with a previous change to the perf error return ABI) for
calling out in userspace the exact reason for perf record failing
when PMU doesn't support overflow interrupts.

Note that this needs to be put ahead of existing precise_ip check as
that gets hit otherwise for the sampling fail case as well.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <acme@redhat.com>
Cc: <linux-snps-arc@lists.infradead.org>
Cc: <vincent.weaver@maine.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Link: http://lkml.kernel.org/r/1462786660-2900-2-git-send-email-vgupta@synopsys.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent a1396555

tools/perf/util/evsel.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -2384,6 +2384,9 @@ int perf_evsel__open_strerror(struct perf_evsel evsel, struct target target,
		"No such device - did you specify an out-of-range profile CPU?");
		break;
		case EOPNOTSUPP:
		if (evsel->attr.sample_period != 0)
		return scnprintf(msg, size, "%s",
		"PMU Hardware doesn't support sampling/overflow-interrupts.");
		if (evsel->attr.precise_ip)
		return scnprintf(msg, size, "%s",
		"\'precise\' request may not be supported. Try removing 'p' modifier.");

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