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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 6A2A2C11F68 for ; Wed, 30 Jun 2021 14:46:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54D236147E for ; Wed, 30 Jun 2021 14:46:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235467AbhF3OtX (ORCPT ); Wed, 30 Jun 2021 10:49:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235345AbhF3OtR (ORCPT ); Wed, 30 Jun 2021 10:49:17 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B423C061756 for ; Wed, 30 Jun 2021 07:46:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=KjwCOuTmi8CUrJtJez24s7BgJwdIjA4AHyQ1AizC1g0=; b=bu77fQHkWnZaJr0mkBXBX68giI D/V3h+n3SyDxYmUopA2l5oTQSPdSXI9qHKlXtKiTJE9CGFKgBxidojmEbUfIgXrpOdrs6UQX/UbOU ELhSfGuLi9YPoFZw7qnR7Hdebl4lm0ng7Q/Sg+rbeMJM2BPQfFrGnEcwlp0n+/RtSmwe/Zhd0oGQ4 G0Gn0VUkoDzCO5/vddm3SV5Q+k9/3Pi7ze6zgaZHLprKKNUsRLrdSLBbRW9FZZ6+WJMjgEhNFFIPm FZXbWiFgi2PBmBHB12RwdrzIpggXa6ud8y/um3ABaveHKMibrFg4VCa53sbLv2LvyqoFFE48D0www w+vZDeIg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1lybU8-00DCF2-Lm; Wed, 30 Jun 2021 14:46:40 +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) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 47A1D300091; Wed, 30 Jun 2021 16:46:39 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 3651B2C59D783; Wed, 30 Jun 2021 16:46:39 +0200 (CEST) Date: Wed, 30 Jun 2021 16:46:39 +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> <139a3dc2-1693-5e33-3d2d-77a5651d92e1@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <139a3dc2-1693-5e33-3d2d-77a5651d92e1@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 30, 2021 at 10:13:06AM -0400, Waiman Long wrote: > Sorry, I missed the XXX comment:-) > > This is a generic problem as other waiters that go into the spinning loop > also don't check for sigpending. On the other hand, I am fine with doing the > pending signal check before doing the optimistic spinning. True.. OK, lemme write changelogs for the 4 patches I've ended up with and post them. Then we can look at that whole sigpending crud.