On Tue, Sep 08, 2020 at 01:42:24PM +0900, Namhyung Kim wrote: > Hello, > > When we profile cgroup events with perf stat, it's very annoying to > specify events and cgroups on the command line as it requires the > mapping between events and cgroups. (Note that perf record can use > cgroup sampling but it's not usable for perf stat). > > I guess most cases we just want to use a same set of events (N) for > all cgroups (M), but we need to specify NxM events and NxM cgroups. > This is not good especially when profiling large number of cgroups: > say M=200. > > So I added --multiply-cgroup option to make it easy for that case. It > will create NxM events from N events and M cgroups. One more upside > is that it can handle metrics too.
agreed that it's PITA to use -G option ;-) > > For example, the following example measures IPC metric for 3 cgroups > > $ cat perf-multi-cgrp.sh > #!/bin/sh > > METRIC=${1:-IPC} > CGROUP_DIR=/sys/fs/cgroup/perf_event > > sudo mkdir $CGROUP_DIR/A $CGROUP_DIR/B $CGROUP_DIR/C > > # add backgroupd workload for each cgroup > echo $$ | sudo tee $CGROUP_DIR/A/cgroup.procs > /dev/null > yes > /dev/null & > echo $$ | sudo tee $CGROUP_DIR/B/cgroup.procs > /dev/null > yes > /dev/null & > echo $$ | sudo tee $CGROUP_DIR/C/cgroup.procs > /dev/null > yes > /dev/null & > > # run 'perf stat' in the root cgroup > echo $$ | sudo tee $CGROUP_DIR/cgroup.procs > /dev/null > perf stat -a -M $METRIC --multiply-cgroup -G A,B,C sleep 1 would it be easier to have new option for this? like: perf stat -a -M $METRIC --for-cgroup A,B,C perf stat -a -M $METRIC --for-each-cgroup A,B,C perf stat -a -M $METRIC --attach-cgroup A,B,C perf stat -a -M $METRIC --attach-to-cgroup A,B,C I'm still not sure how the --multiply-cgroup deals with empty cgroup A,,C but looks like we don't need this behaviour now? thanks, jirka