Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp2531942imu; Mon, 17 Dec 2018 03:40:33 -0800 (PST) X-Google-Smtp-Source: AFSGD/U1Oug84t7I6xtbes+ZwKqVnid5kFAY0jSFcA4NIFGb/Kg7pvqlHkhRg6wr/j+uAN/5xdP4 X-Received: by 2002:a63:160d:: with SMTP id w13mr12135534pgl.43.1545046833683; Mon, 17 Dec 2018 03:40:33 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1545046833; cv=none; d=google.com; s=arc-20160816; b=LQtg89fmg4A8uBISBFEJ5TLcfw0B7fQaCKn7xJMamRFbxAuX6eofv7ZywtlBefUPf9 ibVht3T9lE4YIKzaAQbZtbRqixPlze27IT/2ZpLEOQc/r09QtgI1sswYTyRCez4YSBaH 06KwfAxAKuKB6zRLIYWkkoz5PtkAlArf7FR+WB+FnDWQrRgDluuqq7e4yuIFALnHcW0o TUcAsT3ZIi2Z3nb0jlBbZFcoqESdpF3v/BBha9kI/X/x+Ud5P1EGJ5wsKGtYao7Cp3pw 0uPS8KT3kjtoiioSTpHeEvMOya5vggNEftEzc0HSSSaTcv++yYrExUIAldhnLksWc+ny 6z4A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature; bh=Ypto5pGNyOfQlEOm+YoX2DZmroFPlTLVGI1R7JIUX/0=; b=YAy/kwvbgDKA71rWNP7s1zrKLMAEbmgcxxq8RWdKMxLzJd+DMU2x+tHQyl8cWvmbeP wqi3syj0+2PzQsbVDom2nxI21q460hkn9IQFKqGvdGBT5Z3H3UCi39vQO9P3ihXZ0H4v v2xwlWSSWhZxTKDEE82U5ONbwNJz9vozBI8cUhKch3113xCz2nKYtY8PSEN60CHNAZg4 zlmNmOwXBRM3ZiFliiDZatoOc9VXXCgXHib8dv3btUC4Vfc7u8Yoz/00JJby/59evN6l Ru/xiX2m2IFcPZ42BMNfttukPMNFHvJfX3sGTxsZdWmUk39IFuHJ5BuvPHCqcD17Ji9y 6b4g== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@infradead.org header.s=merlin.20170209 header.b="G/iAKWlp"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id g33si11105777pgm.426.2018.12.17.03.40.18; Mon, 17 Dec 2018 03:40:33 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=merlin.20170209 header.b="G/iAKWlp"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731780AbeLQLhk (ORCPT + 99 others); Mon, 17 Dec 2018 06:37:40 -0500 Received: from merlin.infradead.org ([205.233.59.134]:52640 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726965AbeLQLhk (ORCPT ); Mon, 17 Dec 2018 06:37:40 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Ypto5pGNyOfQlEOm+YoX2DZmroFPlTLVGI1R7JIUX/0=; b=G/iAKWlpOg1A87j0TS05WwRCM JQRP2MPW0FlGK5N4lJrudIH1rajpTK2YtwkuoW0B7OxfLHjui5eOkhwNZtCn4rRcJ2LIsuP6ZrSpw 0NdLlXHtpRmjLaWBVdxjvjYb3ZUgBthYukDT4gJQarTJZX98X/6za8vQf1Smt/0SGQnizPhuwOg+n 2/neZnzCVG8kbj4FApFbs+QH1dWaL7Qw8Uvgs7SIsr4icyw/do61uAo3Lnb7GxXU2+6Eonw5XDVy7 EBod6cE8oQ3+RK1rMatNwk5hyF89smB9YvhpHzdaebxack0gEP9I/DLgvhvOX6ozhvs2pPBRra4Hm Uf2s8DKZA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gYrD9-0008Uo-81; Mon, 17 Dec 2018 11:37:23 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id EA9E7984437; Mon, 17 Dec 2018 12:37:18 +0100 (CET) Date: Mon, 17 Dec 2018 12:37:18 +0100 From: Peter Zijlstra To: Yongji Xie Cc: dave@stgolabs.net, mingo@redhat.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, Xie Yongji , zhangyu31@baidu.com, liuqi16@baidu.com, yuanlinsi01@baidu.com, nixun@baidu.com, lilin24@baidu.com, longman@redhat.com, andrea.parri@amarulasolutions.com Subject: Re: [RFC] locking/rwsem: Avoid issuing wakeup before setting the reader waiter to nil Message-ID: <20181217113718.GB4900@worktop.programming.kicks-ass.net> References: <5598cd71-c3c8-d6ef-eb30-777cf901a2ef@redhat.com> <20181129160627.GU2131@hirez.programming.kicks-ass.net> <8cc45695-b325-a219-8b46-d5da6ddfdd63@redhat.com> <20181129172700.GA11632@hirez.programming.kicks-ass.net> <20181129180828.GA11650@hirez.programming.kicks-ass.net> <729ceddb-dd9a-ec2a-f74e-03fa4d7e65e8@redhat.com> <20181129213017.v3eljor54lfpoug2@linux-r8p5> <20181129213421.wwvhsjql3m3lvtv4@linux-r8p5> <20181129221714.GF11632@hirez.programming.kicks-ass.net> 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) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 10, 2018 at 11:12:52PM +0800, Yongji Xie wrote: > Hi Peter, > > Please let me know If there is any progress on this issue. Thank you! Right, sorry, my brain was filled with snot and didn't want to make sense of things. I've put some patches here: git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git locking/core Could you have a look?