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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 5F9C3C2D0DB for ; Sat, 25 Jan 2020 20:29:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 208A320708 for ; Sat, 25 Jan 2020 20:29:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="a9eF+DOz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727409AbgAYU3y (ORCPT ); Sat, 25 Jan 2020 15:29:54 -0500 Received: from mail.skyhub.de ([5.9.137.197]:39104 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726454AbgAYU3x (ORCPT ); Sat, 25 Jan 2020 15:29:53 -0500 Received: from zn.tnic (p200300EC2F1CE900698071F6EB5AEF0D.dip0.t-ipconnect.de [IPv6:2003:ec:2f1c:e900:6980:71f6:eb5a:ef0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id ED1DD1EC0AA0; Sat, 25 Jan 2020 21:29:51 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1579984192; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=UGB09dF/Gks2th5CmJckVsOZrAsgXGHQ//Z+awLH+4A=; b=a9eF+DOz+IwZjF0FdxjplFQzHXpS5MEEa5GMPZOGmSEQOxH3Kfbs8wZOstD29OKm814GF+ uDHBHw5HCGwnN9qfT5uTcQynbax8fS/mKdkg/Z9SRswH7mIkeMHo1b9aKl6QBY6+uT9TEM HuiEQqCeM+dOUf+/i33QtEQP0LZsUNg= Date: Sat, 25 Jan 2020 21:29:51 +0100 From: Borislav Petkov To: "Luck, Tony" Cc: Thomas Gleixner , Arvind Sankar , "Christopherson, Sean J" , Peter Zijlstra , Ingo Molnar , "Yu, Fenghua" , Ingo Molnar , H Peter Anvin , "Raj, Ashok" , "Shankar, Ravi V" , linux-kernel , x86 Subject: Re: [PATCH v15] x86/split_lock: Enable split lock detection by kernel Message-ID: <20200125202951.GD4369@zn.tnic> References: <20200122224245.GA2331824@rani.riverdale.lan> <3908561D78D1C84285E8C5FCA982C28F7F54887A@ORSMSX114.amr.corp.intel.com> <20200123004507.GA2403906@rani.riverdale.lan> <20200123035359.GA23659@agluck-desk2.amr.corp.intel.com> <20200123044514.GA2453000@rani.riverdale.lan> <20200123231652.GA4457@agluck-desk2.amr.corp.intel.com> <87h80kmta4.fsf@nanos.tec.linutronix.de> <20200125024727.GA32483@agluck-desk2.amr.corp.intel.com> <20200125104419.GA16136@zn.tnic> <20200125195513.GA15834@agluck-desk2.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200125195513.GA15834@agluck-desk2.amr.corp.intel.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 Sat, Jan 25, 2020 at 11:55:13AM -0800, Luck, Tony wrote: > I don't have a good abbreviation. It would become the joint 2nd longest > flag name ... top ten lengths look like this on my test machine. So while > long, not unprecedented. Yah, I guess we lost that battle long ago. > Thomas explained how to fix it so we only call the function if TIF_SLD > is set in either the previous or next process (but not both). So the > overhead is just extra XOR/AND in the caller. Yeah. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette