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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 C0400C00449 for ; Wed, 3 Oct 2018 13:13:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 770392089F for ; Wed, 3 Oct 2018 13:13:32 +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="uqwI6ycQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 770392089F 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 S1726834AbeJCUBv (ORCPT ); Wed, 3 Oct 2018 16:01:51 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:36428 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726630AbeJCUBv (ORCPT ); Wed, 3 Oct 2018 16:01:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Subject:Cc:To:From:Date:Message-ID: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=WkfQxyOWBTJo0qlNDlWmD3Jz8rOqJPy8U0ahFjOFfbs=; b=uqwI6ycQmYFxg+oqyo3U/isDq VUG2AxVAvC0D+M1ck2XY3RZMCIi/urunbPNyo4qayc8yzGqAk1cFeW2qrXS1c2/d6cyYu0Fy3tBdW T386vEid90+6PUA08K7YLUzv0/K8u2yXNFBhz3LVt1n6h6GZuvGecvx/z/CEY/h6Kp7i92hVPy3TH P+EDG/eQkZjucEBQqGzyX/Ubhdk5SprxufVbTg91G7AQ1I1dgx3W4DIdJTpHDFS4n6mJWK0LDgYRA 69s+Xx90GNkVjvcBcu6lxyd57ATdg0fw9P9OE5lt3iDVIdNBm+2UgfPFiGZJejc1DgrEVyU+d3HNV xllfnX1cQ==; 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 1g7gxu-0003Aq-J1; Wed, 03 Oct 2018 13:13:23 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 12FEA202C1A14; Wed, 3 Oct 2018 15:13:15 +0200 (CEST) Message-ID: <20181003130257.156322446@infradead.org> User-Agent: quilt/0.65 Date: Wed, 03 Oct 2018 15:02:57 +0200 From: Peter Zijlstra To: will.deacon@arm.com, mingo@kernel.org Cc: linux-kernel@vger.kernel.org, longman@redhat.com, andrea.parri@amarulasolutions.com, tglx@linutronix.de, bigeasy@linutronix.de, Peter Zijlstra Subject: [PATCH v2 0/4] locking/qspinlock, x86: Improve determinism for x86 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Back when Will did his qspinlock determinism patches, we were left with one cmpxchg loop on x86 due to the use of atomic_fetch_or(). Will proposed a nifty trick: http://lkml.kernel.org/r/20180409145409.GA9661@arm.com While that didn't quite work, this series implements that basic idea. Changes since v1: - Adjusted comments in #2, wildea01 - 'Simplified' GEN_*_RMWcc, peterz - Rewrote _the_ patch to use BTS, wildea01