Em Thu, May 30, 2013 at 01:02:39PM +0200, Peter Zijlstra escreveu: > On Thu, May 30, 2013 at 11:53:06AM +0200, Jiri Olsa wrote: > > Currently the perf_events_attr::wakeup_events logic is > > checked only for regular samples.
> So something like this came up before and ISTR doing a patch similar to > what you propose but ended up not going with it because... uhm... > I have vague memories about people (possibly me) wanting wake_events to > mean samples. Like get me a wakeup every 20 samples. With your patch the > side-band events now also count towards 'events'. I think it was me, and the test case is tools/perf/pythoh/twatch.py, that just wants those side band events, the "fix" was: commit cfeb1d90a1b1db96383b48888cb7a5f10ca12e12 Author: Arnaldo Carvalho de Melo <[email protected]> Date: Mon Jan 30 14:43:21 2012 -0200 perf python: Use attr.watermark in twatch.py We want to be woken up for every PERF_RECORD_ event, attr.wakeup_events is only for PERF_RECORD_SAMPLE, so also use attr.watermark = 1 to fix that. > I think the most common use of wake_events is people setting it to 1 and > have perf generate a SIGfoo for every sample so they can do magic in > their userspace signal handler. This is popular for interpreters. > > It would be unfortunate to get SIGfoos for side-band chatter. > > > Makes sense? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
