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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 84D91EAD79C for ; Thu, 12 Jul 2018 18:11:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D871213A2 for ; Thu, 12 Jul 2018 18:11:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="GwrwK7C3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D871213A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726728AbeGLSVu (ORCPT ); Thu, 12 Jul 2018 14:21:50 -0400 Received: from mail-it0-f66.google.com ([209.85.214.66]:52481 "EHLO mail-it0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726444AbeGLSVu (ORCPT ); Thu, 12 Jul 2018 14:21:50 -0400 Received: by mail-it0-f66.google.com with SMTP id p4-v6so8103126itf.2 for ; Thu, 12 Jul 2018 11:11:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=7Kc8gvEjY/sJDU3kniCAuWeH+ScBR3Ojts/E3OM9Yiw=; b=GwrwK7C3wFKpHftBRBUZvzwbSEiAvg51YB+gASFes8YGTVvgT9RQdV4deD8e44MB4z vUtoYluX/+vkPYQC6v/73NK6h10vhCZkFsyauQnBgxw8hHYPtaaMGmlQeYHRT2j3EJNi kkznZfZMZu47ex5u1BJULUQIdlBNzIp4lmzjM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=7Kc8gvEjY/sJDU3kniCAuWeH+ScBR3Ojts/E3OM9Yiw=; b=FNg6qdlldxxz5y66MuRpRco4KTg4LsVCzQmGDg6NY9fgJf8jBIaC0WMyj+H3UrD6ok A9b8yB7aLfl4W7u1Ewj/W41ZBu9ZQBHrgFfSt9Ov7sodAGisB/qwZOMUMcbNBeh5nhkX hYzhUDIXyA1M2ngwiy7lwbyyKc47zYsWFAYfQ3W5aaUvs+ZjaKA5tX1CUx3X4CVwgJEc x/H56KwMHZ8fLHgiIACZEbJEfZz/avf3JrVeKp4iaNeNRGbx0908s0RFgjv7g06y91ac R4gTmJp2cjDCqgPTTvJpGeFlQvPaJ0l2S6WkX/5Q7D/nbj1WZBzSjNXwGyYmLB2s2iZg O9+g== X-Gm-Message-State: AOUpUlFs+dROjkHRt6rh9xDaDzpYJZDnCfPU49vQubDp/CRUxQVi9/cs qO+pueBVpNHW0zM5frDQWbZLnXFonysQIiHMGP0= X-Google-Smtp-Source: AAOMgpeuXBebW8pEKkAxP7n3b3WfS8USgW2HviUWWzAF3sQrVKiqSq3yLaSPbDCwZ1z6v/DTCYVN24fRONpLsIA/LCg= X-Received: by 2002:a02:1bdc:: with SMTP id 89-v6mr2481671jas.72.1531419069410; Thu, 12 Jul 2018 11:11:09 -0700 (PDT) MIME-Version: 1.0 References: <20180712134821.GT2494@hirez.programming.kicks-ass.net> <20180712172838.GU3593@linux.vnet.ibm.com> <20180712180511.GP2476@hirez.programming.kicks-ass.net> In-Reply-To: <20180712180511.GP2476@hirez.programming.kicks-ass.net> From: Linus Torvalds Date: Thu, 12 Jul 2018 11:10:58 -0700 Message-ID: Subject: Re: [PATCH v2] tools/memory-model: Add extra ordering for locks and remove it for ordinary release/acquire To: Peter Zijlstra Cc: Paul McKenney , Alan Stern , andrea.parri@amarulasolutions.com, Will Deacon , Akira Yokosawa , Boqun Feng , Daniel Lustig , David Howells , Jade Alglave , Luc Maranget , Nick Piggin , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 12, 2018 at 11:05 AM Peter Zijlstra wrote: > > The locking pattern is fairly simple and shows where RCpc comes apart > from expectation real nice. So who does RCpc right now for the unlock-lock sequence? Somebody mentioned powerpc. Anybody else? How nasty would be be to make powerpc conform? I will always advocate tighter locking and ordering rules over looser ones.. Linus