Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758544Ab2BNCgi (ORCPT ); Mon, 13 Feb 2012 21:36:38 -0500 Received: from mail-qy0-f174.google.com ([209.85.216.174]:48352 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750757Ab2BNCgh convert rfc822-to-8bit (ORCPT ); Mon, 13 Feb 2012 21:36:37 -0500 MIME-Version: 1.0 In-Reply-To: <20120213204937.GF12117@google.com> References: <20120208162925.GA19392@google.com> <20120209175948.GE19392@google.com> <20120209192431.GF19392@google.com> <20120209234844.GG19392@google.com> <20120211021724.GO19392@google.com> <20120213204937.GF12117@google.com> Date: Tue, 14 Feb 2012 10:36:36 +0800 X-Google-Sender-Auth: EblF7AfI5P5Zm0SJFdZV7zFKeRo Message-ID: Subject: Re: [PATCH] block: strip out locking optimization in put_io_context() From: Shaohua Li To: Tejun Heo Cc: Jens Axboe , Vivek Goyal , lkml , Knut Petersen , mroos@linux.ee, Linus Torvalds Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1052 Lines: 21 2012/2/14 Tejun Heo : > Hello, Shaohua. > > Can you please test the following patch? ?It's combination of three > patches which invokes elevator icq exit from exit_io_context(). ?This > unfortunately ends up adding another reverse locking loop and using > RCU could be better; unfortunately, the change isn't trivial due to > q->queue_lock modification during blk_cleanup_queue() and ioc cleanup > being called after that from blk_release_queue() - IOW, while holding > RCU, we might end up grabbing the wrong q lock (I don't think this is > a new problem). > > Now that we have proper request draining on queue exit, we can > probably move ioc clearing and other operations to blk_cleanup_queue() > and then apply RCU, but that's for another merge window. This fixed the regression. Thanks! -- 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/