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 e23smtp03.au.ibm.com (8.13.1/8.13.1) with ESMTP id m89E3ZnP028050 for ; Wed, 10 Sep 2008 00:03:35 +1000 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 v9.0) with ESMTP id m89E4gYf242360 for ; Wed, 10 Sep 2008 00:04:44 +1000 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 m89E4f4m003651 for ; Wed, 10 Sep 2008 00:04:42 +1000 Message-ID: <48C6826B.9000202@linux.vnet.ibm.com> Date: Tue, 09 Sep 2008 07:04:27 -0700 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com MIME-Version: 1.0 Subject: Re: [RFC][PATCH 6/14] memcg: lockless page cgroup 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> In-Reply-To: <20080909165608.878d7182.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: Daisuke Nishimura , "linux-mm@kvack.org" List-ID: 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. > I don't think this should take long to do. It's really easy to do (I've tried two approaches and it look me a day to get them working). I am trying some other approach based on early_init and alloc_bootmem*. > So please be patient for a while. -- 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