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 763DDC433E0 for ; Mon, 13 Jul 2020 09:21:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 506E2206D9 for ; Mon, 13 Jul 2020 09:21:58 +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="Zwj5RIHx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728382AbgGMJV5 (ORCPT ); Mon, 13 Jul 2020 05:21:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726360AbgGMJV4 (ORCPT ); Mon, 13 Jul 2020 05:21:56 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C4B5C061755; Mon, 13 Jul 2020 02:21:56 -0700 (PDT) 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; bh=P/bW5/nprUcxPT3l7Gpx8eG76PtPDRhEsmWS6Xfaf74=; b=Zwj5RIHxYYDF0P/F8xkgcDLK/R vHSnMafKuEB7KReKLmzAE/RZ76JPXiM/CTH4Q/dgMswpIW13wpAyUP5vGqzlkUmk2ma1k4HZunRh9 S2zo/UXptc3oKvzwkKEUAAt/yQcCCD93dsd0a0v2GDXWGlvbzj6dMOX3AuvvD1jppbF+un5yi5qXf kidPV315rMgO86C0AyYnOJv96BsgORXu0UyFlME+mPjOcytvrU8nSGRpFqrLFBCilPHWYzlNugrAX z0hP8GpK1z6JwliCORWDsYhDbIWdGQti/oEqVg6jmICjGIV/gVduKO5eB9XZOIBNsG+AxoAAkQI9v WNHinH7Q==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1juuea-0006nD-Aj; Mon, 13 Jul 2020 09:21:40 +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 934E03007CD; Mon, 13 Jul 2020 11:21:35 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 8213720D27AA0; Mon, 13 Jul 2020 11:21:35 +0200 (CEST) Date: Mon, 13 Jul 2020 11:21:35 +0200 From: Peter Zijlstra To: Waiman Long Cc: Ingo Molnar , Will Deacon , Thomas Gleixner , Borislav Petkov , Arnd Bergmann , linux-kernel@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org, Nicholas Piggin , Davidlohr Bueso Subject: Re: [PATCH 2/2] locking/pvqspinlock: Optionally store lock holder cpu into lock Message-ID: <20200713092135.GC10769@hirez.programming.kicks-ass.net> References: <20200711182128.29130-1-longman@redhat.com> <20200711182128.29130-3-longman@redhat.com> <20200712173452.GB10769@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jul 12, 2020 at 07:05:36PM -0400, Waiman Long wrote: > On 7/12/20 1:34 PM, Peter Zijlstra wrote: > > And this kills it,.. if it doesn't make unconditional sense, we're not > > going to do this. It's just too ugly. > > > You mean it has to be unconditional, no option config if we want to do it. > Right? Yeah, the very last thing we need in this code is spurious complexity.