Hi Stephane, On Wed, Sep 23, 2020 at 6:52 AM Stephane Eranian <eran...@google.com> wrote: > > Hi, > > On Mon, Sep 21, 2020 at 2:46 AM Namhyung Kim <namhy...@kernel.org> wrote: > > > > The --for-each-cgroup option is a syntax sugar to monitor large number > > of cgroups easily. Current command line requires to list all the > > events and cgroups even if users want to monitor same events for each > > cgroup. This patch addresses that usage by copying given events for > > each cgroup on user's behalf. > > > > For instance, if they want to monitor 6 events for 200 cgroups each > > they should write 1200 event names (with -e) AND 1200 cgroup names > > (with -G) on the command line. But with this change, they can just > > specify 6 events and 200 cgroups with a new option. > > > > A simpler example below: It wants to measure 3 events for 2 cgroups > > ('A' and 'B'). The result is that total 6 events are counted like > > below. > > > > $ ./perf stat -a -e cpu-clock,cycles,instructions --for-each-cgroup A,B > > sleep 1 > > > You could also do it by keeping the -G option and providing > --for-each-cgroup as a modifier > of the behavior of -G: > > $ ./perf stat -a -e cpu-clock,cycles,instructions --for-each-cgroup -G > A,B sleep 1 > > That way, you do not have to handle the case where both are used. > And it makes transitioning to the new style simpler, i.e., the -G > option remains, just need > to trim the number of cgroups to 200 in your example. > > Just a suggestion.
Thanks for the suggestion. Actually that's the approach I took in my v1 submission. And Jiri suggested the current way. Personally I'm fine with either. Thanks Namhyung