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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 D518FC433DB for ; Wed, 17 Mar 2021 17:41:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0F0364EF2 for ; Wed, 17 Mar 2021 17:41:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231604AbhCQRlJ (ORCPT ); Wed, 17 Mar 2021 13:41:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229939AbhCQRkn (ORCPT ); Wed, 17 Mar 2021 13:40:43 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A69FCC06174A; Wed, 17 Mar 2021 10:40:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=vg/NxtC+FUWyuBFjfo8bGAaIZSPPvuY3LqUFygsfcDE=; b=A0j/Kt3/HS2x+KWi+tgYY6jnch +WDTvjgl453QexQhUj+zzxY8jQhBsFkJSf5Odo/lPac85gj5psiHbhEdu3gzWIIg5BDel+/0zVtSe YxInHQX5cJBo27QmABY5DE2IwUQeGdeN6jEvzD7abwpkJeGNrr1DUYuUUk+pezquYMOR8aXWw7dRG pXyJV0mRQkEZjAyWWbdwDB+jzC+7dB6UzV1iiic/FEVw62iS0gN/UIpfmxq1iOoPqnng/2R2gmNmU e6FA4SKVUKXukgD4LrmS4TDrm78yf0gGTCMBwomUlzRgD2CdkSPbfES5wjrSCkaS/pzT+2GlpHhxC e8vbjvog==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lMa9j-001vaQ-RG; Wed, 17 Mar 2021 17:40:33 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 82A1E305C10; Wed, 17 Mar 2021 18:40:27 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7160F2C051CD8; Wed, 17 Mar 2021 18:40:27 +0100 (CET) Date: Wed, 17 Mar 2021 18:40:27 +0100 From: Peter Zijlstra To: Waiman Long Cc: linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org, Ingo Molnar , x86@kernel.org Subject: Re: [tip: locking/urgent] locking/ww_mutex: Treat ww_mutex_lock() like a trylock Message-ID: References: <20210316153119.13802-4-longman@redhat.com> <161598470197.398.8903908266426306140.tip-bot2@tip-bot2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 17, 2021 at 05:48:48PM +0100, Peter Zijlstra wrote: > I think you'll find that if you use ww_mutex_init() it'll all work. Let > me go and zap this patch, and then I'll try and figure out why > DEFINE_WW_MUTEX() is buggered. Moo, I can't get the compiler to do as I want :/ The below is so close but doesn't actually compile.. Maybe we should just give up on DEFINE_WW_MUTEX and simply remove it. --- diff --git a/include/linux/mutex.h b/include/linux/mutex.h index 0cd631a19727..85f50538f26a 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -129,12 +129,15 @@ do { \ # define __DEP_MAP_MUTEX_INITIALIZER(lockname) #endif -#define __MUTEX_INITIALIZER(lockname) \ +#define ___MUTEX_INITIALIZER(lockname, depmap) \ { .owner = ATOMIC_LONG_INIT(0) \ , .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \ , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \ __DEBUG_MUTEX_INITIALIZER(lockname) \ - __DEP_MAP_MUTEX_INITIALIZER(lockname) } + depmap } + +#define __MUTEX_INITIALIZER(lockname) \ + ___MUTEX_INITIALIZER(lockname, __DEP_MAP_MUTEX_INITIALIZER(lockname)) #define DEFINE_MUTEX(mutexname) \ struct mutex mutexname = __MUTEX_INITIALIZER(mutexname) diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h index 6ecf2a0220db..c62a030652b4 100644 --- a/include/linux/ww_mutex.h +++ b/include/linux/ww_mutex.h @@ -50,9 +50,17 @@ struct ww_acquire_ctx { #ifdef CONFIG_DEBUG_LOCK_ALLOC # define __WW_CLASS_MUTEX_INITIALIZER(lockname, class) \ - , .ww_class = class + , .ww_class = &(class) + +# define __DEP_MAP_WW_MUTEX_INITIALIZER(lockname, class) \ + , .dep_map = { \ + .key = &(class).mutex_key, \ + .name = (class).mutex_name, \ + .wait_type_inner = LD_WAIT_SLEEP, \ + } #else # define __WW_CLASS_MUTEX_INITIALIZER(lockname, class) +# define __DEP_MAP_WW_MUTEX_INITIALIZER(lockname, class) #endif #define __WW_CLASS_INITIALIZER(ww_class, _is_wait_die) \ @@ -62,7 +70,8 @@ struct ww_acquire_ctx { , .is_wait_die = _is_wait_die } #define __WW_MUTEX_INITIALIZER(lockname, class) \ - { .base = __MUTEX_INITIALIZER(lockname.base) \ + { .base = ___MUTEX_INITIALIZER(lockname.base, \ + __DEP_MAP_WW_MUTEX_INITIALIZER(lockname.base, class)) \ __WW_CLASS_MUTEX_INITIALIZER(lockname, class) } #define DEFINE_WD_CLASS(classname) \ diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 0ab94e1f1276..e8305233eb0b 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -358,9 +358,9 @@ static struct lock_torture_ops mutex_lock_ops = { #include static DEFINE_WD_CLASS(torture_ww_class); -static DEFINE_WW_MUTEX(torture_ww_mutex_0, &torture_ww_class); -static DEFINE_WW_MUTEX(torture_ww_mutex_1, &torture_ww_class); -static DEFINE_WW_MUTEX(torture_ww_mutex_2, &torture_ww_class); +static DEFINE_WW_MUTEX(torture_ww_mutex_0, torture_ww_class); +static DEFINE_WW_MUTEX(torture_ww_mutex_1, torture_ww_class); +static DEFINE_WW_MUTEX(torture_ww_mutex_2, torture_ww_class); static int torture_ww_mutex_lock(void) __acquires(torture_ww_mutex_0)