From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756625AbbJ2DIa (ORCPT ); Wed, 28 Oct 2015 23:08:30 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:33347 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751301AbbJ2DI2 (ORCPT ); Wed, 28 Oct 2015 23:08:28 -0400 Date: Thu, 29 Oct 2015 12:08:22 +0900 From: Tejun Heo To: Tetsuo Handa Cc: cl@linux.com, akpm@linux-foundation.org, mhocko@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, hannes@cmpxchg.org, mgorman@suse.de Subject: Re: [patch 3/3] vmstat: Create our own workqueue Message-ID: <20151029030822.GD27115@mtj.duckdns.org> References: <20151028024114.370693277@linux.com> <20151028024131.719968999@linux.com> <20151028024350.GA10448@mtj.duckdns.org> <201510282057.JHI87536.OMOFFFLJOHQtVS@I-love.SAKURA.ne.jp> <20151029022447.GB27115@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151029022447.GB27115@mtj.duckdns.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 29, 2015 at 11:24:47AM +0900, Tejun Heo wrote: > Hello, > > That's weird. > > On Wed, Oct 28, 2015 at 08:57:28PM +0900, Tetsuo Handa wrote: > > [ 272.851035] Showing busy workqueues and worker pools: > > [ 272.852583] workqueue events: flags=0x0 > > [ 272.853942] pwq 6: cpus=3 node=0 flags=0x0 nice=0 active=1/256 > > [ 272.855781] pending: vmw_fb_dirty_flush [vmwgfx] > > [ 272.857500] pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 > > [ 272.859359] pending: vmpressure_work_fn > > [ 272.860840] workqueue events_freezable_power_: flags=0x84 > > [ 272.862461] pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 > > [ 272.864479] in-flight: 11286:disk_events_workfn > > What's this guy doing? Can you get stack dump on 11286 (or whatever > is in flight in the next lockup)? Wait, this series doesn't include Tetsuo's change. Of course it won't fix the deadlock problem. What's necessary is Tetsuo's patch + WQ_MEM_RECLAIM. Thanks. -- tejun