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_CR_TRAILER, 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 1093FC11F65 for ; Wed, 30 Jun 2021 14:03:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E766261437 for ; Wed, 30 Jun 2021 14:03:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235412AbhF3OGN (ORCPT ); Wed, 30 Jun 2021 10:06:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235417AbhF3OFl (ORCPT ); Wed, 30 Jun 2021 10:05:41 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6257C061766 for ; Wed, 30 Jun 2021 06:57:35 -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=L1x+KUBDu+pQNQroM2CacolCsjEtk/jUpjV5NXpjLGM=; b=rIVW6WGlDCGlZcjjtomWTCJK58 kszRhsKEgikdaav4vC6m134gi2Ww/ZbLIqwR8R3KZKooEUSOsHxDwd5IcfxFQPRmC2spEfLizgpii KD/qZbMrTQZ9ppQ+9uQs5k3phiCSud1lCjpGUt151AechVCG3y3HIAkSIncwkyU8wstEpbdeXFfY2 gwBVSMPUaIMOgfWOsz6rK3+l8I46bMbZcrQ6+l+wATDNdqVchYq5NiJ3H4i30j1bOP/E5/PjnA6jQ k1trot4ua0lEnhn4xfgvULGDy1JeElvJVl360527rokC6xmG9xnDHrHNEzxv4d/PYptxOZBvopl5k b/thshHQ==; 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 #2 (Red Hat Linux)) id 1lyahu-005Q5f-V0; Wed, 30 Jun 2021 13:56:58 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 2BBB8300091; Wed, 30 Jun 2021 15:56:50 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 0980D2C59D783; Wed, 30 Jun 2021 15:56:50 +0200 (CEST) Date: Wed, 30 Jun 2021 15:56:49 +0200 From: Peter Zijlstra To: Waiman Long Cc: Ingo Molnar , Will Deacon , Boqun Feng , linux-kernel@vger.kernel.org, "Xu, Yanfei" Subject: Re: [PATCH] locking/mutex: Reduce chance of setting HANDOFF bit on unlocked mutex Message-ID: References: <20210629201138.31507-1-longman@redhat.com> 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, Jun 30, 2021 at 09:50:11AM -0400, Waiman Long wrote: > The code looks good to me. It is an even better approach to make sure that > the HANDOFF will never be set on an unlocked mutex. > > Reviewed-by: Waiman Long Thanks, what about that XXX? Should we not check sigpending before doing the optimistic spinning thing?