On Wed 09-08-17 15:06:34, wang Yu wrote: > Hello Johannes ,Michal,and Tejun: > > i using memcg v1, but some reason i want to context to memcg v2, > but i can't, here is my step: > #cat /proc/cgroups > #subsys_name hierarchy num_cgroups enabled > memory 5 1 1 > #cd /sys/fs/cgroup/memory > #mkdir a > #echo 0 > a/cgroup.procs > #sleep 1 > #echo 0 > cgroup.procs This doesn't do what you think. It will try to add a non-existant pid 0 to the root cgroup. You need to remove cgroup a. Moreover it is possible that the `sleep' command will fault some page cache and that will stay in memcg `a' until there is a memory pressure. cgroup v1 had force_empty knob which you can use to drain the cgroup before removal. Then you should be able to umount the v1 cgroup and mount v2. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
