From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [patch 1/3] raid5: offload stripe handle to workqueue Date: Wed, 31 Jul 2013 06:33:32 -0400 Message-ID: <20130731103332.GE2810@htj.dyndns.org> References: <20130730055207.698660010@kernel.org> <20130730055257.527231772@kernel.org> <20130730125306.GC2599@htj.dyndns.org> <20130730130708.GA30352@kernel.org> <20130730135751.GD12016@htj.dyndns.org> <20130731012434.GA1504@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20130731012434.GA1504@kernel.org> Sender: linux-raid-owner@vger.kernel.org To: Shaohua Li Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, neilb@suse.de, djbw@fb.com List-Id: linux-raid.ids Hello, On Wed, Jul 31, 2013 at 09:24:34AM +0800, Shaohua Li wrote: > stripe is the work unit actually. As I said, if I queue a work for each stripe, > just queue_work() will make the system blast because of the pwq->pool->lock > contention. dispatching one work has another side effect that I can't add block Hmmm.... I see. I'm not familiar with the code base and could be missing something but how does the custom stripe dispatch queue synchronize? Doesn't that make use of a lock anyway? If so, how would scheduling separate work items be worse? Also, can you please elaborate the block plug part? Thanks. -- tejun