Messages in this thread | | | From | Namhyung Kim <> | Date | Fri, 13 Oct 2023 15:57:27 -0700 | Subject | Re: [PATCH] perf bench sched pipe: Add -G/--cgroups option |
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Hi Arnaldo,
On Fri, Oct 13, 2023 at 3:41 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > Em Wed, Oct 04, 2023 at 01:47:41PM -0700, Namhyung Kim escreveu: > > The -G/--cgroups option is to put sender and receiver in different > > cgroups in order to measure cgroup context switch overheads. > > > > Users need to make sure the cgroups exist and accessible. > > > > # perf stat -e context-switches,cgroup-switches \ > > > taskset -c 0 perf bench sched pipe -l 10000 > /dev/null > > > > Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000': > > > > 20,001 context-switches > > 2 cgroup-switches > > > > 0.053449651 seconds time elapsed > > > > 0.011286000 seconds user > > 0.041869000 seconds sys > > > > # perf stat -e context-switches,cgroup-switches \ > > > taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB > /dev/null > > > > Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 10000 -G AAA,BBB': > > > > 20,001 context-switches > > 20,001 cgroup-switches > > > > 0.052768627 seconds time elapsed > > So I tried with: > > [root@quaco ~]# perf bench sched pipe -G system.slice,user.slice > # Running 'sched/pipe' benchmark: > cannot enter to cgroup: system.slice > cannot enter to cgroup: user.slice > # Executed 1000000 pipe operations between two processes > > Total time: 6.301 [sec] > > 6.301478 usecs/op > 158692 ops/sec > [root@quaco ~]# > > Should't it bail out when not managing to enter the cgroups?
Hmm.. right. Will fix.
> > Also: > > [root@quaco ~]# mkdir /sys/fs/cgroup/AAA > [root@quaco ~]# mkdir /sys/fs/cgroup/BBB > [root@quaco ~]# > [root@quaco ~]# perf bench sched pipe -G AAA,BBB > # Running 'sched/pipe' benchmark: > cannot enter to cgroup: AAA > cannot enter to cgroup: BBB > # Executed 1000000 pipe operations between two processes > > Total time: 6.397 [sec] > > 6.397830 usecs/op > 156302 ops/sec > [root@quaco ~]# > > -rw-r--r--. 1 root root 0 Oct 13 19:22 /sys/fs/cgroup/AAA/cgroup.procs > [root@quaco ~]# ls -la /sys/fs/cgroup/AAA/cgroup.threads > -rw-r--r--. 1 root root 0 Oct 13 19:22 /sys/fs/cgroup/AAA/cgroup.threads > [root@quaco ~]# ls -la /sys/fs/cgroup/BBB/cgroup.threads > -rw-r--r--. 1 root root 0 Oct 13 19:22 /sys/fs/cgroup/BBB/cgroup.threads > [root@quaco ~]# ls -la /sys/fs/cgroup/BBB/cgroup.procs > -rw-r--r--. 1 root root 0 Oct 13 19:22 /sys/fs/cgroup/BBB/cgroup.procs > [root@quaco ~]# > > [root@quaco ~]# perf bench sched pipe -G AAA,BBB > # Running 'sched/pipe' benchmark: > cannot enter to cgroup: AAA (written=-1, len=6, errno=Operation not supported) > cannot enter to cgroup: BBB (written=-1, len=6, errno=Operation not supported) > # Executed 1000000 pipe operations between two processes > > Total time: 6.303 [sec] > > 6.303221 usecs/op > 158649 ops/sec > [root@quaco ~]# > > I'm certainly missing something here :-\
Try to enable some cgroup controllers first. Like
# echo +cpu > /sys/fs/cgroup/AAA/cgroup.subtree_control # echo +cpu > /sys/fs/cgroup/BBB/cgroup.subtree_control
Thanks, Namhyung
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