From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sd0109e.au.ibm.com (d23rh905.au.ibm.com [202.81.18.225]) by e23smtp06.au.ibm.com (8.13.1/8.13.1) with ESMTP id mAD1KxBH022171 for ; Thu, 13 Nov 2008 12:20:59 +1100 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by sd0109e.au.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id mAD1KjTA292748 for ; Thu, 13 Nov 2008 12:20:45 +1100 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id mAD1Kjuq003454 for ; Thu, 13 Nov 2008 12:20:45 +1100 Message-ID: <491B80E8.4090107@linux.vnet.ibm.com> Date: Thu, 13 Nov 2008 06:50:40 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com MIME-Version: 1.0 Subject: Re: [RFC][PATCH 1/6] memcg: free all at rmdir References: <20081112122606.76051530.kamezawa.hiroyu@jp.fujitsu.com> <20081112122656.c6e56248.kamezawa.hiroyu@jp.fujitsu.com> <20081112160758.3dca0b22.akpm@linux-foundation.org> <20081113101344.6882c209.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20081113101344.6882c209.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, nishimura@mxp.nes.nec.co.jp, menage@google.com List-ID: KAMEZAWA Hiroyuki wrote: > On Wed, 12 Nov 2008 16:07:58 -0800 > Andrew Morton wrote: > >> On Wed, 12 Nov 2008 12:26:56 +0900 >> KAMEZAWA Hiroyuki wrote: >> >>> +5.1 on_rmdir >>> +set behavior of memcg at rmdir (Removing cgroup) default is "drop". >>> + >>> +5.1.1 drop >>> + #echo on_rmdir drop > memory.attribute >>> + This is default. All pages on the memcg will be freed. >>> + If pages are locked or too busy, they will be moved up to the parent. >>> + Useful when you want to drop (large) page caches used in this memcg. >>> + But some of in-use page cache can be dropped by this. >>> + >>> +5.1.2 keep >>> + #echo on_rmdir keep > memory.attribute >>> + All pages on the memcg will be moved to its parent. >>> + Useful when you don't want to drop page caches used in this memcg. >>> + You can keep page caches from some library or DB accessed by this >>> + memcg on memory. >> Would it not be more useful to implement a per-memcg version of >> /proc/sys/vm/drop_caches? (One without drop_caches' locking bug, >> hopefully). >> >> If we do this then we can make the above "keep" behaviour non-optional, >> and the operator gets to choose whether or not to drop the caches >> before doing the rmdir. >> >> Plus, we get a new per-memcg drop_caches capability. And it's a nicer >> interface, and it doesn't have the obvious races which on_rmdir has, >> etc. >> >> hm? >> > In my plan, I'll add > > memory.shrink_usage interface to do and allows > > #echo 0M > memory.shrink_memory_usage > (you may swap tasks out if there is task..) > > to drop pages. > So, shrink_memory_usage is just for dropping caches? I don't understand the part about swap tasks out. > Balbir, how do you think ? I've already removed "force_empty". Have you? Won't that go against API/ABI compatibility guidelines. I would recommend cc'ing linux-api as well. Sorry, I missed the patch that removes force_empty. Me culpa. -- Balbir -- 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