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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 6D072C433E1 for ; Thu, 13 Aug 2020 11:42:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DEAF20771 for ; Thu, 13 Aug 2020 11:42:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="M1f7WYXv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726533AbgHMLmA (ORCPT ); Thu, 13 Aug 2020 07:42:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726100AbgHMLk6 (ORCPT ); Thu, 13 Aug 2020 07:40:58 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B250BC061757; Thu, 13 Aug 2020 04:40:57 -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=2DtpeNiIF6S/B3g+Kt5wUDgMBKVuFkosm757FNhgE1A=; b=M1f7WYXvppktqa9ZEJqZQXmJpI nWu1Csk9GhX1CtV5cvYEJLOo8ChGp77nDsOHCcJKT0Jh5QV34M25cdhhxaAKdnDr7mAr480EC43XI 9u+QgduTuSIMLKuOyYrOoCoVdhDH0KTAaHewOHXoutZ6kvy56QTN4C6jAOSOt2LTckyPQLq+CDnJY rrHz6/AKg7/tmBA9F/t1npfuFaFSPiMHfz4cJUo+mGvFvZ0SSw1A0cx2dmuCcPeXU45rdCpYnY4Qp 3jHOwqPVNaFlnM2/UWdAQa/Y6/SCW7lY7U4/WBfNG/HCNY6vrJ+jCgk85/e0Er05EkZWyuWVuFZCx Kn0V7eew==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k6BbH-0002Qu-QI; Thu, 13 Aug 2020 11:40:52 +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 A20343003E5; Thu, 13 Aug 2020 13:40:50 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 8E30F2C217FE7; Thu, 13 Aug 2020 13:40:50 +0200 (CEST) Date: Thu, 13 Aug 2020 13:40:50 +0200 From: peterz@infradead.org To: Christoph Hellwig Cc: Jacob Wen , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] block: insert a general SMP memory barrier before wake_up_bit() Message-ID: <20200813114050.GW2674@hirez.programming.kicks-ass.net> References: <20200813024438.13170-1-jian.w.wen@oracle.com> <20200813073115.GA15436@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200813073115.GA15436@infradead.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 13, 2020 at 08:31:15AM +0100, Christoph Hellwig wrote: > On Thu, Aug 13, 2020 at 10:44:38AM +0800, Jacob Wen wrote: > > wake_up_bit() uses waitqueue_active() that needs the explicit smp_mb(). > > Sounds like the barrier should go into wake_up_bit then.. Oh, thanks for reminding me.. https://lkml.kernel.org/r/20190624165012.GH3436@hirez.programming.kicks-ass.net I'll try and get back to that.