On Wed, Dec 17, 2014 at 3:20 AM, Zefan Li <lize...@huawei.com> wrote: > On 2014/12/17 1:17, Vince Weaver wrote: >> On Mon, 15 Dec 2014, Stephane Eranian wrote: >>> On Mon, Dec 15, 2014 at 11:01 PM, Arnaldo Carvalho de Melo >>> <arnaldo.m...@gmail.com> wrote: >> >>> fs is visible. The cgroup file system type is not there anymore. They are >>> using >>> tmpfs which is not ideal to detect just cgroup. Looks like now, we have to >>> look >>> at the mount point which is flaky. >> >> The trivial fix is to just always assume things will be under >> /sys/fs/cgroup >> which looks like to be the new official mount point. >> >> This will break on older systems though, or systems that mount cgroupfs in >> multiple locations. >> >> Another alternative is to change the interface to require the full >> cgroupfs pathname as an argument to -G >> > > What's the problem here? > > none /sys/fs/cgroup tmpfs rw,relatime,size=4k,mode=755 0 0 > systemd /sys/fs/cgroup/systemd cgroup > rw,nosuid,nodev,noexec,relatime,perf_event,name=systemd 0 0 > > cgroup is mounted in /sys/fs/cgroup/systemd, so you should pass '/' to the -G > argument: > Is that the only mountpoint possible? The tool needs to detect a valid mount point to locate the named cgroup. That's assuming that if I create cgroup foo, then it appears under //sys/fs/cgroup/systemd/foo
> sudo perf stat -a -e cycles:u,cycles:u,cycles:u -G / -- sleep 1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/