On Fri, 2010-10-22 at 16:09 +0800, Li Zefan wrote: > Stephane posted a patchset to add perf_cgroup subsystem, so perf can > be used to monitor all threads belonging to a cgroup. > > But if you already mounted a cgroup hierarchy but without perf_cgroup > and the hierarchy has sub-cgroups, you can't bind perf_cgroup to it, > and thus you're not able to use per-cgroup perf feature. > > This patchset alleviates the pain, and then a subsytem can be > bound/unbound to/from a hierarchy which has sub-cgroups in it. > > Some subsystems still can't take advantage of this patchset, memcgroup > and cpuset in specific. > > For cpuset, if a hierarchy has a sub-cgroup and the cgroup has tasks, > we can't decide sub-cgroup's cpuset.mems and cpuset.cpus automatically > if we try to bind cpuset to this hierarchy. > > For memcgroup, memcgroup uses css_get/put(), and due to some complexity, > for now bindable subsystems should not use css_get/put(). > > Usage: > > # mount -t cgroup -o cpuset xxx /mnt > # mkdir /mnt/tmp > # echo $$ > /mnt/tmp/tasks > > (add cpuacct to the hierarchy) > # mount -o remount,cpuset,cpuacct xxx /mnt > > (remove it from the hierarchy) > # mount -o remount,cpuset xxx /mnt > > There's another limitation, cpuacct should not be bound to any mounted > hierarchy before the above operation. But that's not a problem, as you > can remove it from a hierarchy and bind it to another one.
Right, so the only remaining problem I see with this approach is that you cannot profile two different hierarchies at the same time, but I can't really think of a solution to that problem (nor do I care very much). Seems like a nice approach, Thanks Li! _______________________________________________ Containers mailing list contain...@lists.linux-foundation.org https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list Devel@openvz.org https://openvz.org/mailman/listinfo/devel
