On Thu, Apr 12, 2012 at 4:17 AM, KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > In recent discussion, Tejun Heo, cgroup maintainer, has a plan to remove > ->pre_destroy(). And now, in cgroup tree, pre_destroy() failure cause WARNING. > > By pre_destroy(), rmdir of cgroup can return -EBUSY or some error. > It makes cgroup complicated and unstable. I said O.K. to remove it and > this patch is modification for memcg. > > One of problem in current implementation is that memcg moves all charges to > parent in pre_destroy(). At doing so, if use_hierarchy=0, pre_destroy() may > hit parent's limit and may return -EBUSY. To fix this problem, this patch > changes behavior of rmdir() as > > - if use_hierarchy=0, all remaining charges will go to root cgroup. > - if use_hierarchy=1, all remaining charges will go to the parent. We need to update the "4.3 Removing a cgroup" session in Documentation. --Ying > By this, rmdir failure will not be caused by parent's limitation. And > I think this meets meaning of use_hierarchy. > > This series does > - add above change of behavior > - use workqueue to move all pages to parent > - remove unnecessary codes. > > I'm sorry if my reply is delayed, I'm not sure I can have enough time in > this weekend. Any comments are welcomed. > > Thanks, > -Kame > > > -- > 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/ . > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href