Commit-ID: a1396555abff9ff9b74c2e4da13e27e81fd094b2 Gitweb: http://git.kernel.org/tip/a1396555abff9ff9b74c2e4da13e27e81fd094b2 Author: Vineet Gupta <Vineet.Gupta1 at synopsys.com> AuthorDate: Mon, 9 May 2016 15:07:40 +0530 Committer: Ingo Molnar <mingo at kernel.org> CommitDate: Fri, 3 Jun 2016 09:40:42 +0200 perf/abi: Change the errno for sampling event not supported in hardware Change the return code for sampling event not supported from -ENOTSUPP to -EOPNOTSUPP. This allows userspace to identify this case specifically, instead of printing the catch-all error message it did previously. Technically this is an ABI change, but we think we can get away with it. Old behavior: ------- | # perf record ls | Error: | The sys_perf_event_open() syscall returned with 524 (Unknown error 524) | for event (cycles:ppp). | /bin/dmesg may provide additional information. | No CONFIG_PERF_EVENTS=y kernel support configured? New behavior: ------- | # perf record ls | Error: | PMU Hardware doesn't support sampling/overflow-interrupts. Signed-off-by: Vineet Gupta <vgupta at synopsys.com> Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.org> Cc: <acme at redhat.com> Cc: <linux-snps-arc at lists.infradead.org> Cc: <vincent.weaver at maine.edu> Cc: Alexander Shishkin <alexander.shishkin at linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme at redhat.com> Cc: Jiri Olsa <jolsa at redhat.com> Cc: Linus Torvalds <torvalds at linux-foundation.org> Cc: Peter Zijlstra <peterz at infradead.org> Cc: Stephane Eranian <eranian at google.com> Cc: Thomas Gleixner <tglx at linutronix.de> Cc: Vince Weaver <vincent.weaver at maine.edu> Cc: Vineet Gupta <Vineet.Gupta1 at synopsys.com> Link: http://lkml.kernel.org/r/1462786660-2900-3-git-send-email-vgupta at synopsys.com Signed-off-by: Ingo Molnar <mingo at kernel.org> --- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index f94f164..5d48306 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9309,7 +9309,7 @@ SYSCALL_DEFINE5(perf_event_open, if (is_sampling_event(event)) { if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) { - err = -ENOTSUPP; + err = -EOPNOTSUPP; goto err_alloc; } }
