On Mon, Jul 03, 2017 at 01:10:04PM -0300, Arnaldo Carvalho de Melo wrote: > Em Mon, Jul 03, 2017 at 05:16:54PM +0200, Jiri Olsa escreveu: > > On Mon, Jul 03, 2017 at 11:57:39AM -0300, Arnaldo Carvalho de Melo wrote: > > > Em Mon, Jul 03, 2017 at 04:50:16PM +0200, Jiri Olsa escreveu: > > > > The kernel fails to add a non sampling event event > > > > with having precise_ip set. > > > > > > > > Make sure the precise_ip is 0 when using -n option > > > > to create non sampling event in record. > > > > > > Ok, but how could that happen? What was the scenario? Which command? Can > > > you provide a command line that causes the problem? > > > > [jolsa@krava perf]$ ./perf record -e cycles:ppp -n ls > > Lowering default frequency rate to 3000. > > Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate. > > Error: > > The sys_perf_event_open() syscall returned with 22 (Invalid argument) for > > event (cycles:pppu). > > /bin/dmesg may provide additional information. > > No CONFIG_PERF_EVENTS=y kernel support configured? > > > > v2 attached, thanks > > Ok, so the user asks for --no-samples but at the same time asks for > precision equal to :ppp, we should stop right there and warn the user > that that is not possible, instead of silently dropping off what the > user explicitely asked.
well I take this option more like debug/devel one.. you have failing command line and want to investigate the kernel state without having samples generated under your fingers can't see why would normal user need it > > I'm cooking a few patches to allow that, then we can apply your patch, > that, with the current set of users will never kick in :-) ok jirka
