From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f43.google.com (mail-pa0-f43.google.com [209.85.220.43]) by kanga.kvack.org (Postfix) with ESMTP id 862956B0038 for ; Mon, 21 Sep 2015 17:53:19 -0400 (EDT) Received: by padbj2 with SMTP id bj2so2656248pad.3 for ; Mon, 21 Sep 2015 14:53:19 -0700 (PDT) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net. [150.101.137.141]) by mx.google.com with ESMTP id aa9si40757890pbd.56.2015.09.21.14.53.17 for ; Mon, 21 Sep 2015 14:53:18 -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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1442833794-23117-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> Sender: owner-linux-mm@kvack.org List-ID: To: Tetsuo Handa Cc: xfs@oss.sgi.com, linux-mm@kvack.org 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 -- 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