On 2014/12/17 10:29, Stephane Eranian wrote: > 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 >
There can be only one cgroupfs mountpoint which has perf_event subsystem attached to it. So for this setup: mount -t tmpfs /sys/fs/cgroup mkdir /sys/fs/cgroup/memory mkdir /sys/fs/cgroup/perf mount -t cgroup -o memory memcg /sys/fs/cgroup/memory mount -t cgroup -o perf_event perf /sys/fs/cgroup/perf The perf tool will locate the mountpoint as /sys/fs/cgroup/perf. -- 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/
