From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx119.postini.com [74.125.245.119]) by kanga.kvack.org (Postfix) with SMTP id 8934F6B007E for ; Thu, 22 Mar 2012 20:26:45 -0400 (EDT) Date: Thu, 22 Mar 2012 17:30:00 -0700 From: Andrew Morton Subject: Re: [PATCH] memcg: change behavior of moving charges at task move Message-Id: <20120322173000.f078a43f.akpm@linux-foundation.org> In-Reply-To: <4F6BC166.80407@jp.fujitsu.com> References: <4F69A4C4.4080602@jp.fujitsu.com> <20120322143610.e4df49c9.akpm@linux-foundation.org> <4F6BC166.80407@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , Linux Kernel , "cgroups@vger.kernel.org" , Hugh Dickins , "n-horiguchi@ah.jp.nec.com" , Johannes Weiner , Michal Hocko , Glauber Costa On Fri, 23 Mar 2012 09:18:46 +0900 KAMEZAWA Hiroyuki wrote: > >> +#ifdef CONFIG_SWAP > >> + /* > >> + * Avoid lookup_swap_cache() not to update statistics. > >> + */ > > > > I don't understand this comment - what is it trying to tell us? > > > > > High Dickins advised me to use find_get_page() rather than lookup_swap_cache() > because lookup_swap_cache() has some statistics with swap. ah. --- a/mm/memcontrol.c~memcg-change-behavior-of-moving-charges-at-task-move-fix +++ a/mm/memcontrol.c @@ -5137,7 +5137,8 @@ static struct page *mc_handle_swap_pte(s return NULL; #ifdef CONFIG_SWAP /* - * Avoid lookup_swap_cache() not to update statistics. + * Use find_get_page() rather than lookup_swap_cache() because the + * latter alters statistics. */ page = find_get_page(&swapper_space, ent.val); #endif > >> + page = find_get_page(&swapper_space, ent.val); > > > > The code won't even compile if CONFIG_SWAP=n? > > > > mm/built-in.o: In function `mc_handle_swap_pte': > /home/kamezawa/Kernel/next/linux/mm/memcontrol.c:5172: undefined reference to `swapper_space' > make: *** [.tmp_vmlinux1] Error 1 > > Ah...but I think this function (mc_handle_swap_pte) itself should be under CONFIG_SWAP. > I'll post v2. Confused. The new reference to swapper_space is already inside #ifdef CONFIG_SWAP. -- 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