On Mon, Jul 03, 2017 at 01:40:01PM -0300, Arnaldo Carvalho de Melo wrote: > Em Mon, Jul 03, 2017 at 06:22:28PM +0200, Jiri Olsa escreveu: > > 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 :-) > > Take a look at: > > https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/commit/?h=perf/core&id=9f6e7e8bbb99feb6d721be7ccefb8c9139fa5abb > > and: > > https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/commit/?h=perf/core&id=f9a4297945a99b47f92b111b5b1802a3b295a1a7 > > Its in my perf/core branch now.
I think I'd just go for simple warning once we detect -n and :p but if you think error is necessary I'll live ;-) jirka
