From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751389AbaDUB3z (ORCPT ); Sun, 20 Apr 2014 21:29:55 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:46478 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751217AbaDUB3x (ORCPT ); Sun, 20 Apr 2014 21:29:53 -0400 X-IronPort-AV: E=Sophos;i="4.97,894,1389715200"; d="scan'208";a="29499096" Message-ID: <53547574.4090207@cn.fujitsu.com> Date: Mon, 21 Apr 2014 09:33:40 +0800 From: Lai Jiangshan User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc14 Thunderbird/3.1.4 MIME-Version: 1.0 To: Lai Jiangshan CC: Tejun Heo , LKML Subject: Re: [PATCH 0/6] workqueue: simpler&better workers management synchronization References: <1397299543-12012-1-git-send-email-laijs@cn.fujitsu.com> <53491A85.70004@cn.fujitsu.com> In-Reply-To: <53491A85.70004@cn.fujitsu.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.226.103] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/12/2014 06:50 PM, Lai Jiangshan wrote: > Sorry, > the cover letter was forgotten to send to LKML. Hi, Tejun Any comments about the patchset. (general comments, high level comments) Thanks. Lai > > On 04/12/2014 06:45 PM, Lai Jiangshan wrote: >> Each patches remove codes! >> >> Patch1&2 are the basic patches. They add a *united* mechanism for managing >> percpu pools' workers' & unbound pools' workers' & rescuers' CPUMASK. >> >> Patch1&4 make workers-concurrency-enabling atomically when cpu_online() >> and create_worker(). after this, workers-concurrency-enabling-disabling >> are all atomically. >> >> Old manager_mutex protects: >> 1) workers creation&destruction >> 2) workers cpumask managing when cpu_online()/workers-creation >> 3) workers concurrency enabling&disabling. >> >> Now, the above three things' synchronization are separated. >> 1) We don't need manager_mutex protects workers creation&destruction >> 1.1) creation is only happened when the cpu is first online, the unbound pool >> is just created, and manage_workers(). they have their one synchronization. >> 1.2) destruction only happens on idle-timeout handler, protected by pool->lock. >> 1.3) put_unbound_pool() uses manager_arb&workers_leave(new) to synchronize >> with workers creation&destruction. >> >> 2) bind_mutex and bind_list handle all the workers'(percpu,unbound, >> normal,rescuer) cpumask when cpu_online()/workers-creation/worker-destrution. >> we don't need manager_mutex. >> >> 3) pool->lock and worker_idr handle workers concurrency enabling&disabling. >> >> Note, bind_list is always a super set of worker_idr, and when cpu-online or >> workers-creation, cpumask is set at first and then concurrency-enabling. >> concurrency-management depends on local-wakeup which depends on cpumask >> is properly set for all the workers. >> >> This patchset depends on previous patch: >> "workqueue: fix possible race condition when rescuer VS pwq-release" >> >> Thanks, >> Lai >> >> >> Lai Jiangshan (6): >> workqueue: generic routine to restore percpu/unbound pools' workers' >> cpumask >> workqueue: generic framework to manage normal&rescuer workers' >> cpumask >> workqueue: make destroy_worker() atomically >> workqueue: commit worker to pool's concurrency setting atomically. >> workqueue: remove manager_mutex >> workqueue: destroy worker directly in idle timeout handler >> >> kernel/workqueue.c | 366 ++++++++++++------------------------------ >> kernel/workqueue_internal.h | 1 + >> 2 files changed, 106 insertions(+), 261 deletions(-) >> > > . >