From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx102.postini.com [74.125.245.102]) by kanga.kvack.org (Postfix) with SMTP id 2805F6B004D for ; Thu, 5 Jan 2012 00:56:52 -0500 (EST) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 4C8323EE0C1 for ; Thu, 5 Jan 2012 14:56:50 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 2EB1A45DE50 for ; Thu, 5 Jan 2012 14:56:50 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 1605E45DE4F for ; Thu, 5 Jan 2012 14:56:50 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 0801D1DB802F for ; Thu, 5 Jan 2012 14:56:50 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id B08F71DB803E for ; Thu, 5 Jan 2012 14:56:49 +0900 (JST) Date: Thu, 5 Jan 2012 14:55:35 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 1/4] memcg: fix split_huge_page_refcounts Message-Id: <20120105145535.56c8c7fe.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Andrea Arcangeli , Shaohua Li , David Rientjes , linux-mm@kvack.org On Wed, 28 Dec 2011 16:20:25 -0800 (PST) Hugh Dickins wrote: > This patch started off as a cleanup: __split_huge_page_refcounts() has to > cope with two scenarios, when the hugepage being split is already on LRU, > and when it is not; but why does it have to split that accounting across > three different sites? Consolidate it in lru_add_page_tail(), handling > evictable and unevictable alike, and use standard add_page_to_lru_list() > when accounting is needed (when the head is not yet on LRU). > > But a recent regression in -next, I guess the removal of PageCgroupAcctLRU > test from mem_cgroup_split_huge_fixup(), makes this now a necessary fix: > under load, the MEM_CGROUP_ZSTAT count was wrapping to a huge number, > messing up reclaim calculations and causing a freeze at rmdir of cgroup. > > Add a VM_BUG_ON to mem_cgroup_lru_del_list() when we're about to wrap > that count - this has not been the only such incident. Document that > lru_add_page_tail() is for Transparent HugePages by #ifdef around it. > > Signed-off-by: Hugh Dickins seems saner. Acked-by: KAMEZAWA Hiroyuki Thank you. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org