On Thu, Dec 15, 2011 at 03:05:22PM +0900, KAMEZAWA Hiroyuki wrote: > >From 528f5f2667da17c26e40d271b24691412e1cbe81 Mon Sep 17 00:00:00 2001 > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > Date: Thu, 15 Dec 2011 11:41:18 +0900 > Subject: [PATCH 1/5] memcg: simplify account moving check > > Now, percpu variable MEM_CGROUP_ON_MOVE is used for indicating that > a memcg is under move_account() and pc->mem_cgroup under it may be > overwritten. > > But this value is almost read only and not worth to be percpu. > Using atomic_t instread. I like this, but I think you can go one further. The only place I see where the per-cpu counter is actually read is to avoid taking the lock, but if you make that counter an atomic anyway - why bother? Couldn't you remove the counter completely and just take move_lock unconditionally in the page stat updating? -- 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>