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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA4C0C004D4 for ; Wed, 18 Jan 2023 10:15:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230024AbjARKPg (ORCPT ); Wed, 18 Jan 2023 05:15:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46202 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230218AbjARKNX (ORCPT ); Wed, 18 Jan 2023 05:13:23 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BD905955F; Wed, 18 Jan 2023 01:22:03 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8EE18616ED; Wed, 18 Jan 2023 09:22:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6099C433F2; Wed, 18 Jan 2023 09:22:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674033723; bh=DZS895Z+3sptXir0tPzxTsJKKkNp6DzwiYVTcI+Nxas=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kQ7ipcJnCrbNJpn/1LWq84GZ6TR5qt3+KUz1dTKkr0XakM13mE2CdJADXrQLKwcR6 /Y3Z9lMY/yyTr/h9ZUnaD8+HXWyOE5ECHRk5Ms4N/Ok8HHvwCpTGqhjRA0VIalsHhM Me7LShijNUwJaJ0wWn8jIkIIhcRWdLmHJ1kRfvMXLLv6X71hv3leQfEbYu6u3h9QRe CgT19EWFPvSX+s3slPUT+xSyveq5YOLXegUVs4z8Ti9TPBsI0yH1Rys/JCC1QfWt8t ughKXZz3GlLkly1qj6aT0KSqaw88dFUiVD4evJ91gGUyuExYpTAmMoCAcYMW+RlnUq AdP1+leZLv+ng== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1pI4eI-0001cJ-FS; Wed, 18 Jan 2023 10:22:27 +0100 Date: Wed, 18 Jan 2023 10:22:26 +0100 From: Johan Hovold To: Thomas Gleixner Cc: Johan Hovold , Marc Zyngier , x86@kernel.org, platform-driver-x86@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, Hsin-Yi Wang , Mark-PK Tsai Subject: Re: [PATCH v4 06/19] irqdomain: Drop revmap mutex Message-ID: References: <20230116135044.14998-1-johan+linaro@kernel.org> <20230116135044.14998-7-johan+linaro@kernel.org> <871qnslut3.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871qnslut3.ffs@tglx> Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org On Tue, Jan 17, 2023 at 10:23:20PM +0100, Thomas Gleixner wrote: > On Mon, Jan 16 2023 at 14:50, Johan Hovold wrote: > > The global irq_domain_mutex is now held in all paths that update the > > revmap structures so there is no longer any need for the revmap mutex. > > This can also go after the 3rd race fix, but ... > > > static void irq_domain_clear_mapping(struct irq_domain *domain, > > irq_hw_number_t hwirq) > > { > > + lockdep_assert_held(&irq_domain_mutex); > > these lockdep asserts want to be part of the [dis]association race > fixes. They are completely unrelated to the removal of the revmap_mutex. No, they are very much related to the removal of the revmap_mutex. These functions deal with the revmap structures which before this patch were clearly only modified with the revmap_mutex held. The lockdep assert is here to guarantee that my claim that all current (and future) paths that end up modifying these structures do so under the irq_domain_mutex instead. > Your race fixes change the locking and you want to ensure that all > callers comply right there, no? I want to make sure that all callers of these function comply, yes. That's why the asserts belong in this patch. Johan