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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 CFE19C10F0E for ; Fri, 12 Apr 2019 07:05:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9CE0020850 for ; Fri, 12 Apr 2019 07:05:58 +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="t7yIURud" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727002AbfDLHF5 (ORCPT ); Fri, 12 Apr 2019 03:05:57 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:48198 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726101AbfDLHF4 (ORCPT ); Fri, 12 Apr 2019 03:05:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=ohqIoUyux3kWJtgiMUdgYQWefkSRkqRwL0vAokJo07s=; b=t7yIURudTYVwdtwvmqeydntx1 I6K9q0gOYRDpZU5U+xZjP6YpsB2v6Ou6Km90AmNd+r+kdfyMdebnvVaTVKSstUYcmihSErWUJM74O 8823ctd/18o2spwU2FOh8txEF6bJa0PqgucQYvtGgU4gLo89PcdrGrbgpTjPWHiL0tpyag8TwbZzH CWPObDEGQu96PzJGbEAXT1wiKcaX3rx+apnQQDEI+lG8N0B4IW7kuxHOF+Zso/3+c1x63oVfW/PMf mCji21D++SZ9hWpRBCG+mqtRF4P0vM1mzdmk+D8Pilaj4gE9GNL4SyARjcnUD/krVgXkcBpjuqlq8 B9RuAjLMQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEqFv-0000tm-R5; Fri, 12 Apr 2019 07:05:47 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9BD6E203C087C; Fri, 12 Apr 2019 09:05:45 +0200 (CEST) Date: Fri, 12 Apr 2019 09:05:45 +0200 From: Peter Zijlstra To: Ingo Molnar Cc: Waiman Long , Ingo Molnar , Will Deacon , Thomas Gleixner , linux-kernel@vger.kernel.org, x86@kernel.org, Davidlohr Bueso , Linus Torvalds , Tim Chen , huang ying Subject: Re: [PATCH-tip v3 02/14] locking/rwsem: Make owner available even if !CONFIG_RWSEM_SPIN_ON_OWNER Message-ID: <20190412070545.GF11158@hirez.programming.kicks-ass.net> References: <20190410184231.6748-1-longman@redhat.com> <20190410184231.6748-3-longman@redhat.com> <20190411081224.GB4038@hirez.programming.kicks-ass.net> <29aca54a-536e-6e46-7e18-658914c34548@redhat.com> <20190412070209.GC129493@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190412070209.GC129493@gmail.com> 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 Fri, Apr 12, 2019 at 09:02:09AM +0200, Ingo Molnar wrote: > > * Waiman Long wrote: > > > On 04/11/2019 04:12 AM, Peter Zijlstra wrote: > > > On Wed, Apr 10, 2019 at 02:42:19PM -0400, Waiman Long wrote: > > >> The owner field in the rw_semaphore structure is used primarily for > > >> optimistic spinning. However, identifying the rwsem owner can also be > > >> helpful in debugging as well as tracing locking related issues when > > >> analyzing crash dump. The owner field may also store state information > > >> that can be important to the operation of the rwsem. > > >> > > >> So the owner field is now made a permanent member of the rw_semaphore > > >> structure irrespective of CONFIG_RWSEM_SPIN_ON_OWNER. > > > sem->owner is still initialized under CONFIG_RWSEM_SPIN_ON_OWNER. > > > > Oh, you are right. I missed that part. I will fix it in the next version. > > Could you please post the next series against tip:WIP.locking/core, which > is already being dogfood-ed in -tip and which I'm running on my desktop? > I'll backmerge any fixes as needed/requested. Urgh, please no, that's going to be hell to review :/