Commit-ID: a1396555abff9ff9b74c2e4da13e27e81fd094b2 Gitweb: http://git.kernel.org/tip/a1396555abff9ff9b74c2e4da13e27e81fd094b2 Author: Vineet Gupta <[email protected]> AuthorDate: Mon, 9 May 2016 15:07:40 +0530 Committer: Ingo Molnar <[email protected]> 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 <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vince Weaver <[email protected]> Cc: Vineet Gupta <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- 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; } }
