Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751414AbXAFPZh (ORCPT ); Sat, 6 Jan 2007 10:25:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751411AbXAFPZh (ORCPT ); Sat, 6 Jan 2007 10:25:37 -0500 Received: from e2.ny.us.ibm.com ([32.97.182.142]:36096 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751414AbXAFPZg (ORCPT ); Sat, 6 Jan 2007 10:25:36 -0500 Date: Sat, 6 Jan 2007 20:54:14 +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 Subject: Re: [PATCH, RFC] reimplement flush_workqueue() Message-ID: <20070106152413.GB24274@in.ibm.com> Reply-To: vatsa@in.ibm.com References: <20061217223416.GA6872@tv-sign.ru> <20061218162701.a3b5bfda.akpm@osdl.org> <20061219004319.GA821@tv-sign.ru> <20070104113214.GA30377@in.ibm.com> <20070104142936.GA179@tv-sign.ru> <20070104091850.c1feee76.akpm@osdl.org> <20070104180901.GA344@tv-sign.ru> <20070104103107.e33768d7.akpm@osdl.org> <20070105090347.GC18088@in.ibm.com> <20070105140717.GA81@tv-sign.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070105140717.GA81@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: 1136 Lines: 29 On Fri, Jan 05, 2007 at 05:07:17PM +0300, Oleg Nesterov wrote: > How about block_cpu_down() ? Maybe ..not sure If we do introduce such a function, we may need to convert several preempt_disable() that are there already (with intent of blocking cpu_down) to block_cpu_down() .. > These cpu-hotplug races delayed the last workqueue patch I have in my queue. > flush_workqueue() misses an important optimization: we don't need to insert > a barrier and have an extra wake_up + wait_for_completion when cwq has no > pending works. But we need ->current_work (introduced in the next patch) to > implement this correctly. > > I'll re-send the patch below later, when we finish with the bug you pointed > out, but it would be nice if you can take a look now. The patch seems fine to me, though I dont see any cpu hotplug related problem being exposed/solved in this patch. -- 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/