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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, 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 34955ECDFB3 for ; Mon, 16 Jul 2018 19:02:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D937C208E8 for ; Mon, 16 Jul 2018 19:02:14 +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="uA/z4DbK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D937C208E8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.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 S1729854AbeGPTa5 (ORCPT ); Mon, 16 Jul 2018 15:30:57 -0400 Received: from merlin.infradead.org ([205.233.59.134]:56648 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728787AbeGPTa5 (ORCPT ); Mon, 16 Jul 2018 15:30:57 -0400 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=czifFcJx/CQBYKZTBidg5tH9DBcaKhBxu6yQ6nWtT88=; b=uA/z4DbKEHQbd0pbkGS15Nadi dTp/sfq2dREuRFKz9Je5/uc/QGkwAhHwpKdp2A/KwvKf24QVlJXHUcrPcrJb93UeRT9ucpAwIxf/C RykpdO77+FAl9swhWUSMK0lEgDET5RI7nnuNS/BcTIU64IUA7YsiYzfIBrJxqb9SaCJTeK/Zwx/Lu xDrzkphPP4ciA6u+fTvmh9BuE9Urldx69nj9Gy8PAlVqzFgbM0LmOsmRa4HGKSfOCLNFhNTo4fBhu mmnWfrxILfG2xF4bwixHVEruQIsFdA8sK7ELr+VJtGXSqU/tYYptuBel62Mg1FxmmVK58JzXIvaCh GfJ6vmwDw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1ff8ki-00048C-8R; Mon, 16 Jul 2018 19:01:44 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9091920289330; Mon, 16 Jul 2018 21:01:39 +0200 (CEST) Date: Mon, 16 Jul 2018 21:01:39 +0200 From: Peter Zijlstra To: Michael Ellerman Cc: Linus Torvalds , 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 Subject: Re: [PATCH v2] tools/memory-model: Add extra ordering for locks and remove it for ordinary release/acquire Message-ID: <20180716190139.GR2476@hirez.programming.kicks-ass.net> References: <20180712134821.GT2494@hirez.programming.kicks-ass.net> <20180712172838.GU3593@linux.vnet.ibm.com> <20180712180511.GP2476@hirez.programming.kicks-ass.net> <20180713110851.GY2494@hirez.programming.kicks-ass.net> <87tvp3xonl.fsf@concordia.ellerman.id.au> <20180713164239.GZ2494@hirez.programming.kicks-ass.net> <87601fz1kc.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87601fz1kc.fsf@concordia.ellerman.id.au> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 17, 2018 at 12:40:19AM +1000, Michael Ellerman wrote: > > I guess arguably it's not a very macro benchmark, but we have a > context_switch benchmark in the tree[1] which we often use to tune > things, and it degrades badly. It just spins up two threads and has them > ping-pong using yield. The one advantage you'd get from putting it in lock() is that you could do away with smp_mb__after_spinlock(). But yes, I completely forgot about your IO thingy.. those bench results make me sad :/ a well.