From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81014C433E1 for ; Tue, 23 Jun 2020 11:50:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64FE420706 for ; Tue, 23 Jun 2020 11:50:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732596AbgFWLu4 (ORCPT ); Tue, 23 Jun 2020 07:50:56 -0400 Received: from mx2.suse.de ([195.135.220.15]:57060 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732225AbgFWLuy (ORCPT ); Tue, 23 Jun 2020 07:50:54 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 8372EAFB1; Tue, 23 Jun 2020 11:50:52 +0000 (UTC) Date: Tue, 23 Jun 2020 13:50:52 +0200 From: Daniel Wagner To: John Ogness Cc: Jens Axboe , Sebastian Andrzej Siewior , Thomas Gleixner , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] block: remove unnecessary ioc nested locking Message-ID: <20200623115052.comb37q22kjgzyen@beryllium.lan> References: <20200619151718.22338-1-john.ogness@linutronix.de> <20200619151718.22338-2-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200619151718.22338-2-john.ogness@linutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 19, 2020 at 05:23:17PM +0206, John Ogness wrote: > The legacy CFQ IO scheduler could call put_io_context() in its exit_icq() > elevator callback. This led to a lockdep warning, which was fixed in > commit d8c66c5d5924 ("block: fix lockdep warning on io_context release > put_io_context()") by using a nested subclass for the ioc spinlock. > However, with commit f382fb0bcef4 ("block: remove legacy IO schedulers") > the CFQ IO scheduler no longer exists. > > The BFQ IO scheduler also implements the exit_icq() elevator callback but > does not call put_io_context(). > > The nested subclass for the ioc spinlock is no longer needed. Since it > existed as an exception and no longer applies, remove the nested subclass > usage. > > Signed-off-by: John Ogness As far I can tell, looks good. Reviewed-by: Daniel Wagner