On Mon, 13 Feb 2012 23:21:34 -0800 Greg Thelen <gthelen@xxxxxxxxxx> wrote: > On Mon, Feb 13, 2012 at 7:07 PM, KAMEZAWA Hiroyuki > <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > > From 9cdb3b63dc8d08cc2220c54c80438c13433a0d12 Mon Sep 17 00:00:00 2001 > > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > > Date: Thu, 2 Feb 2012 10:02:39 +0900 > > Subject: [PATCH 2/6] memcg: simplify move_account() check. > > > > In memcg, for avoiding take-lock-irq-off at accessing page_cgroup, > > a logic, flag + rcu_read_lock(), is used. This works as following > > > > CPU-A CPU-B > > rcu_read_lock() > > set flag > > if(flag is set) > > take heavy lock > > do job. > > synchronize_rcu() rcu_read_unlock() > > I assume that CPU-A will take heavy lock after synchronize_rcu() when > updating variables read by CPU-B. > Ah, yes. I should wrote that. > > memcontrol.c | 65 ++++++++++++++++++++++------------------------------------- > > 1 file changed, 25 insertions(+), 40 deletions(-) > > > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > > Acked-by: Greg Thelen <gthelen@xxxxxxxxxx> > Thank you!. -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>