Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751799AbXAOEdP (ORCPT ); Sun, 14 Jan 2007 23:33:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751804AbXAOEdP (ORCPT ); Sun, 14 Jan 2007 23:33:15 -0500 Received: from e35.co.us.ibm.com ([32.97.110.153]:44282 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751799AbXAOEdO (ORCPT ); Sun, 14 Jan 2007 23:33:14 -0500 Date: Mon, 15 Jan 2007 10:03:04 +0530 From: Srivatsa Vaddagiri To: Oleg Nesterov Cc: Andrew Morton , David Howells , Christoph Hellwig , Ingo Molnar , Linus Torvalds , linux-kernel@vger.kernel.org, Gautham shenoy , "Pallipadi, Venkatesh" Subject: Re: [PATCH] flush_cpu_workqueue: don't flush an empty ->worklist Message-ID: <20070115043304.GA16435@in.ibm.com> Reply-To: vatsa@in.ibm.com References: <20070107210139.GA2332@tv-sign.ru> <20070108155428.d76f3b73.akpm@osdl.org> <20070109050417.GC589@in.ibm.com> <20070108212656.ca77a3ba.akpm@osdl.org> <20070109150755.GB89@tv-sign.ru> <20070109155908.GD22080@in.ibm.com> <20070109163815.GA208@tv-sign.ru> <20070109164604.GA17915@in.ibm.com> <20070109165655.GA215@tv-sign.ru> <20070114235410.GA6165@tv-sign.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070114235410.GA6165@tv-sign.ru> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 863 Lines: 25 On Mon, Jan 15, 2007 at 02:54:10AM +0300, Oleg Nesterov wrote: > How about the pseudo-code below? Some quick comments: - singlethread_cpu needs to be hotplug safe (broken currently) - Any reason why cpu_populated_map is not modified on CPU_DEAD? - I feel more comfortable if workqueue_cpu_callback were to take workqueue_mutex in LOCK_ACQ and release it in LOCK_RELEASE notifications. This will provide stable access to cpu_populated_map to functions like __create_workqueue. Finally, I wonder if these changes will be unnecessary if we move to process freezer based hotplug locking ... -- Regards, vatsa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/