From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id A41F77F37 for ; Mon, 21 Sep 2015 16:53:20 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay3.corp.sgi.com (Postfix) with ESMTP id 4F52AAC001 for ; Mon, 21 Sep 2015 14:53:20 -0700 (PDT) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id yqWxvy17o3xBBVxE for ; Mon, 21 Sep 2015 14:53:17 -0700 (PDT) Date: Tue, 22 Sep 2015 07:52:41 +1000 From: Dave Chinner Subject: Re: [PATCH] mm, vmscan: Warn about possible deadlock at shirink_inactive_list Message-ID: <20150921215241.GA19114@dastard> References: <1442833794-23117-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1442833794-23117-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Tetsuo Handa Cc: linux-mm@kvack.org, xfs@oss.sgi.com On Mon, Sep 21, 2015 at 08:09:54PM +0900, Tetsuo Handa wrote: > This is a difficult-to-trigger silent hang up bug. > > The kswapd is allowed to bypass too_many_isolated() check in > shrink_inactive_list(). But the kswapd can be blocked by locks in > shrink_page_list() in shrink_inactive_list(). If the task which is > blocking the kswapd is trying to allocate memory with the locks held, > it forms memory reclaim deadlock. It's a known problem in XFS and I'm currently working on patches to fix it by hoisting the memory allocations outside of the CIL context lock. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs