On Thu, Aug 13, 2020 at 4:00 PM Eric Dumazet <eduma...@google.com> wrote: > > On Thu, Aug 13, 2020 at 1:27 AM Sedat Dilek <sedat.di...@gmail.com> wrote: > > > > I run a perf session looks like this in my KDE/Plasma desktop-environment: > > > > [ PERF SESSION ] > > > > 1016 2020-08-13 09:57:24 echo 1 > /proc/sys/kernel/sched_schedstats > > 1017 2020-08-13 09:57:24 echo prandom_u32 >> > > /sys/kernel/debug/tracing/set_event > > 1018 2020-08-13 09:57:24 echo traceon > > > /sys/kernel/debug/tracing/events/random/prandom_u32/trigger > > 1019 2020-08-13 09:57:25 echo 1 > /sys/kernel/debug/tracing/events/enable > > > > 1020 2020-08-13 09:57:32 sysctl -n kernel.sched_schedstats > > 1021 2020-08-13 09:57:32 cat /sys/kernel/debug/tracing/events/enable > > 1022 2020-08-13 09:57:32 grep prandom_u32 > > /sys/kernel/debug/tracing/set_event > > 1023 2020-08-13 09:57:33 cat > > /sys/kernel/debug/tracing/events/random/prandom_u32/trigger > > > > root# /home/dileks/bin/perf record -a -g -e random:prandom_u32 sleep 5 > > > > To be clear : This "perf record -a -g -e random:prandom_u32 sleep 5" > is self sufficient. > > You have nothing to do before (as reported in your email), this is > simply not needed. > > I am not sure why you added all this irrelevant stuff, this is distracting.
Initially I followed these Links: Link: https://www.kernel.org/doc/html/v5.8/trace/events.html Link: https://www.kernel.org/doc/html/v5.8/trace/events.html#boot-option Link: http://www.brendangregg.com/perf.html Link: http://www.brendangregg.com/perf.html#DynamicTracing You are right, it's not needed to set and check all these variables as perf says: root# /home/dileks/bin/perf list | grep prandom_u32 random:prandom_u32 [Tracepoint event] So these two steps are indeed enough: root# /home/dileks/bin/perf record -a -g -e random:prandom_u32 sleep 5 root# /home/dileks/bin/perf report --no-children --stdio Lessons learned. - Sedat -
