On Wed, Dec 21, 2011 at 07:29:34PM +0900, KAMEZAWA Hiroyuki wrote: > Thank you for review. > I'm sorry if my response is delayed. > == > >From 1e8c917c64b3947d2e54c6e5073d53d80bd97c30 Mon Sep 17 00:00:00 2001 > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > Date: Wed, 21 Dec 2011 16:27:25 +0900 > Subject: [PATCH] memcg: return -EINTR at bypassing try_charge(). > > This patch is a fix for memcg-simplify-lru-handling-by-new-rule.patch > When running testprogram and stop it by Ctrl-C, add_lru/del_lru > will find pc->mem_cgroup is NULL and get panic. The reason > is bypass code in try_charge(). > > At try_charge(), it checks the thread is fatal or not as.. > fatal_signal_pending() or TIF_MEMDIE. In this case, __try_charge() > returns 0(success) with setting *ptr as NULL. > > Now, lruvec are deteremined by pc->mem_cgroup. So, it's better > to reset pc->mem_cgroup as root_mem_cgroup. This patch does > following change in try_charge() > 1. return -EINTR at bypassing. > 2. set *ptr = root_mem_cgroup at bypassing. > > By this change, in page fault / radix-tree-insert path, > the page will be charged against root_mem_cgroup and the thread's > operations will go ahead without trouble. In other path, > migration or move_account etc..., -EINTR will stop the operation. > (may need some cleanup later..) > > After this change, pc->mem_cgroup will have valid pointer if > the page is used. > > Changelog: v2 -> v3 > - handle !mm case in another way. > - removed redundant commments > - fixed move_parent bug of uninitialized pointer > Changelog: v1 -> v2 > - returns -EINTR at bypassing. > - change error code handling at callers. > - changed the name of patch. > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Looks good now, thanks. Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> -- 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>