From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 9 Sep 2008 17:11:54 +0900 From: Daisuke Nishimura Subject: Re: [RFC][PATCH 6/14] memcg: lockless page cgroup Message-Id: <20080909171154.f3cfdfd6.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20080909165608.878d7182.kamezawa.hiroyu@jp.fujitsu.com> References: <20080822202720.b7977aab.kamezawa.hiroyu@jp.fujitsu.com> <20080822203551.598a263c.kamezawa.hiroyu@jp.fujitsu.com> <20080909144007.48e6633a.nishimura@mxp.nes.nec.co.jp> <20080909165608.878d7182.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: nishimura@mxp.nes.nec.co.jp, "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" List-ID: On Tue, 9 Sep 2008 16:56:08 +0900, KAMEZAWA Hiroyuki wrote: > On Tue, 9 Sep 2008 14:40:07 +0900 > Daisuke Nishimura wrote: > > > > + /* Double counting race condition ? */ > > > + VM_BUG_ON(page_get_page_cgroup(page)); > > > + > > > page_assign_page_cgroup(page, pc); > > > > > > mz = page_cgroup_zoneinfo(pc); > > > > I got this VM_BUG_ON at swapoff. > > > > Trying to shmem_unuse_inode a page which has been moved > > to swapcache by shmem_writepage causes this BUG, because > > the page has not been uncharged(with all the patches applied). > > > > I made a patch which changes shmem_unuse_inode to charge with > > GFP_NOWAIT first and shrink usage on failure, as shmem_getpage does. > > > > But I don't stick to my patch if you handle this case :) > > > Thank you for testing and sorry for no progress in these days. > > I'm sorry to say that I'll have to postpone this to remove > page->page_cgroup pointer. I need some more performance-improvement > effort to remove page->page_cgroup pointer without significant overhead. > No problem. I know about that :) And, I've started reviewing the radix tree patch and trying to test it. Thanks, Daisuke Nishimura. -- 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