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=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 D5633C433E3 for ; Mon, 29 Mar 2021 14:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4A7661970 for ; Mon, 29 Mar 2021 14:51:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231441AbhC2Ovb (ORCPT ); Mon, 29 Mar 2021 10:51:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:42326 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231434AbhC2OvB (ORCPT ); Mon, 29 Mar 2021 10:51:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B7B2C61932; Mon, 29 Mar 2021 14:50:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617029460; bh=CNpOXw8lVzu5h03kCKJA5hVce5TYus6KlINeK8XkzRQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EyXqJgLhA585RYY/VmTB96DvW+AVS6g5pjyW/s0kPWCtxGKRNKNzPagUvTi3WJmwh BAae2KXVXBvVN977z+WjNtKN7+w1NmySHFUKNq9TzTupDUr/sQMbo2n+JVmPx2KNJ5 1XxxT+Amj0AhNkWtyk8CTDAisij00HrdUMLcP1941mAd798wr5m/kEQQAZ7GU9Fawy ++R/GGmeJa1RSgmQ6qWzLm7RhwBpV9beSwiw1meQT5Fk7ohoLHHKc5I7RWnvHEWt/2 JMMS5R8GngzNs5e/c04Czy+pLpd9aOQ+DwZmAi5BswVOvvLfgOcPYk5rxmude980tZ xipUAAKUybe0g== Date: Mon, 29 Mar 2021 15:50:56 +0100 From: Will Deacon To: Nikitas Angelinas Cc: Peter Zijlstra , Ingo Molnar , Waiman Long , Boqun Feng , linux-kernel@vger.kernel.org Subject: Re: [PATCH] locking/mutex: initialize osq lock in __MUTEX_INITIALIZER() Message-ID: <20210329145055.GC4203@willie-the-truck> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 29, 2021 at 12:15:16AM -0700, Nikitas Angelinas wrote: > Since __MUTEX_INITIALIZER() is used on memory that is initialized to 0 > anyway this change should not have an effect, but it seems better to > initialize osq explicitly for completeness, as done in other macros and > functions that initialize mutex and rwsem. > > Signed-off-by: Nikitas Angelinas > --- > include/linux/mutex.h | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/include/linux/mutex.h b/include/linux/mutex.h > index 515cff7..bff47f8 100644 > --- a/include/linux/mutex.h > +++ b/include/linux/mutex.h > @@ -129,10 +129,18 @@ do { \ > # define __DEP_MAP_MUTEX_INITIALIZER(lockname) > #endif > > +#ifdef CONFIG_MUTEX_SPIN_ON_OWNER > +# define __OSQ_MUTEX_INITIALIZER(lockname) \ > + , .osq = OSQ_LOCK_UNLOCKED > +#else > +# define __OSQ_MUTEX_INITIALIZER(lockname) > +#endif > + > #define __MUTEX_INITIALIZER(lockname) \ > { .owner = ATOMIC_LONG_INIT(0) \ > , .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \ > , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \ > + __OSQ_MUTEX_INITIALIZER(lockname) \ You don't need the lockname parameter for this macro. Will