(2012/11/01 4:44), Tejun Heo wrote: > CGRP_WAIT_ON_RMDIR is another kludge which was added to make cgroup > destruction rollback somewhat working. cgroup_rmdir() used to drain > CSS references and CGRP_WAIT_ON_RMDIR and the associated waitqueue and > helpers were used to allow the task performing rmdir to wait for the > next relevant event. > > Unfortunately, the wait is visible to controllers too and the > mechanism got exposed to memcg by 887032670d ("cgroup avoid permanent > sleep at rmdir"). > > Now that the draining and retries are gone, CGRP_WAIT_ON_RMDIR is > unnecessary. Remove it and all the mechanisms supporting it. Note > that memcontrol.c changes are essentially revert of 887032670d > ("cgroup avoid permanent sleep at rmdir"). > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> > Reviewed-by: Michal Hocko <mhocko@xxxxxxx> > Cc: Balbir Singh <bsingharora@xxxxxxxxx> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> plz forget my comments on v1...But... If swap-in makes a charge before css is deactivated, pre_destroy()->force_empty() will cause infinite loop until it finds a newly charged page in LRU. I think force_empty() will find it by lru_drain() and can make res_coutnter to be 0. I think we need some test with swap-in handling..Anyway, Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html