From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 23 Nov 2008 10:31:16 +0900 From: Daisuke Nishimura Subject: Re: [BUGFIX][PATCH mmotm] memcg: fix for hierarchical reclaim Message-Id: <20081123103116.5dffa39a.d-nishimura@mtf.biglobe.ne.jp> In-Reply-To: <4928113B.8090504@linux.vnet.ibm.com> References: <20081122114446.42ddca46.d-nishimura@mtf.biglobe.ne.jp> <4928113B.8090504@linux.vnet.ibm.com> Reply-To: nishimura@mxp.nes.nec.co.jp Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: balbir@linux.vnet.ibm.com Cc: Andrew Morton , linux-mm@kvack.org, KAMEZAWA Hiroyuki , YAMAMOTO Takashi , Paul Menage , Li Zefan , David Rientjes , Pavel Emelianov , Dhaval Giani , d-nishimura@mtf.biglobe.ne.jp, nishimura@mxp.nes.nec.co.jp List-ID: On Sat, 22 Nov 2008 19:33:39 +0530 Balbir Singh wrote: > Daisuke Nishimura wrote: > > mem_cgroup_from_res_counter should handle both mem->res and mem->memsw. > > This bug leads to NULL pointer dereference BUG at mem_cgroup_calc_reclaim. > > > > Signed-off-by: Daisuke Nishimura > > Thanks for catching this, could you please point me to the steps to reproduce > the problem > You can see this BUG when you are exceeding memory.memsw.limit_in_bytes and trying to free pages. When exceeding memory.memsw.limit_in_bytes, fail_res points to mem_cgroup.memsw, not to mem_cgroup.res. So, mem_cgroup_hierarchical_reclaim() would be called with invalid mem_cgroup. 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