From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kamezawa Hiroyuki Subject: Re: [PATCH 08/11] memcg: disable kmem code when not in use. Date: Tue, 26 Jun 2012 14:51:15 +0900 Message-ID: <4FE94DD3.5060404@jp.fujitsu.com> References: <1340633728-12785-1-git-send-email-glommer@parallels.com> <1340633728-12785-9-git-send-email-glommer@parallels.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1340633728-12785-9-git-send-email-glommer@parallels.com> Sender: owner-linux-mm@kvack.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Glauber Costa Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, Frederic Weisbecker , David Rientjes , Pekka Enberg , Michal Hocko , Johannes Weiner , Christoph Lameter , devel@openvz.org, Tejun Heo , Pekka Enberg , Suleiman Souhlal (2012/06/25 23:15), Glauber Costa wrote: > We can use jump labels to patch the code in or out > when not used. > > Because the assignment: memcg->kmem_accounted = true > is done after the jump labels increment, we guarantee > that the root memcg will always be selected until > all call sites are patched (see mem_cgroup_kmem_enabled). > This guarantees that no mischarges are applied. > > Jump label decrement happens when the last reference > count from the memcg dies. This will only happen when > the caches are all dead. > > Signed-off-by: Glauber Costa > CC: Christoph Lameter > CC: Pekka Enberg > CC: Michal Hocko > CC: Kamezawa Hiroyuki > CC: Johannes Weiner > CC: Suleiman Souhlal Acked-by: KAMEZAWA Hiroyuki -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org