Messages in this thread | | | Date | Tue, 26 Apr 2016 13:33:21 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH/RFC v3] perf core: Allow setting up max frame stack depth via sysctl |
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Em Mon, Apr 25, 2016 at 05:49:38PM -0700, Brendan Gregg escreveu: > On Mon, Apr 25, 2016 at 5:47 PM, Arnaldo Carvalho de Melo > <arnaldo.melo@gmail.com> wrote: > > Em Mon, Apr 25, 2016 at 05:44:00PM -0700, Alexei Starovoitov escreveu: > >> On Mon, Apr 25, 2016 at 09:29:28PM -0300, Arnaldo Carvalho de Melo wrote: > >> > Because we only allocate the callchain percpu data structures when there > >> > is a user, which allows for changing the max easily, its just a matter > >> > of having no callchain users at that point. > >> > > >> > Reported-and-Tested-by: Brendan Gregg <brendan.d.gregg@gmail.com> > >> > Acked-by: Alexei Starovoitov <ast@kernel.org> > >> > >> yep :) > >> hopefully Brendan can give it another spin. > > > > Agreed, and I'm calling it a day anyway, Brendan, please consider > > retesting, thanks,
> Will do, thanks!
> Brendan
So, for completeness, further testing it to see how far it goes on a 8GB machine I got:
[root@emilia ~]# echo 131100 > /proc/sys/kernel/perf_event_max_stack [root@emilia ~]# perf record -g ls Error: The sys_perf_event_open() syscall returned with 12 (Cannot allocate memory) for event (cycles). /bin/dmesg may provide additional information. No CONFIG_PERF_EVENTS=y kernel support configured?
[root@emilia ~]#
[root@emilia ~]# echo 131000 > /proc/sys/kernel/perf_event_max_stack [root@emilia ~]# perf record -g usleep [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.013 MB perf.data (9 samples) ] [root@emilia ~]# ls -la perf.data -rw-------. 1 root root 15736 Apr 26 13:33 perf.data [root@emilia ~]#
- Arnaldo
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