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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 98A9BC32767 for ; Mon, 6 Jan 2020 04:11:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66A5521734 for ; Mon, 6 Jan 2020 04:11:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578283889; bh=B7LdXSi/JWjxK6Dm4iNqV5LXa5Xz3Zef96dIAiZ9mAQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=vN1F+x0/bkgPi9W9QOlO/yrGZlbQ9mAc86V07KeUEYihJ4hTxb+sHun//UzrUtCU/ Yppn7LcF/wxxoLf7aD+GJQ3UfGV9SCYBCFR8Z+2tZa09PgAw1elV8/x+hWzd9s8ouP 6jy5HCDLtELlwcqfR+OO+DTTDzv4p5aL1Jt+jVsM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727501AbgAFEL2 (ORCPT ); Sun, 5 Jan 2020 23:11:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:54602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727432AbgAFEL2 (ORCPT ); Sun, 5 Jan 2020 23:11:28 -0500 Received: from localhost (lfbn-ncy-1-150-155.w83-194.abo.wanadoo.fr [83.194.232.155]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 17FED21582; Mon, 6 Jan 2020 04:11:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578283887; bh=B7LdXSi/JWjxK6Dm4iNqV5LXa5Xz3Zef96dIAiZ9mAQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uuWXR9ITds1qYZMkEPs2chZJ3MZX82/ziVIIMlEk0mvXOpLJlDW7XQpmSofwFBHH7 JZugrGnzEeMErDq+kCEbmphUKE8XGGr19kPQSjhgePQzUZTus3xs9Z8SpZDaJcYsyC eQv32KzvZ5D1tJNrJwjWv1dYcE6DPmZK/HhR/i3c= Date: Mon, 6 Jan 2020 05:11:25 +0100 From: Frederic Weisbecker To: Thomas Gleixner Cc: LKML , x86@kernel.org, Peter Zijlstra , Andy Lutomirski , Will Deacon , Paolo Bonzini , kvm@vger.kernel.org, linux-arch@vger.kernel.org, Mike Rapoport , Josh Poimboeuf , Miroslav Benes Subject: Re: [patch V2 09/17] x86/entry: Remove _TIF_NOHZ from _TIF_WORK_SYSCALL_ENTRY Message-ID: <20200106041124.GA26097@lenoir> References: <20191023122705.198339581@linutronix.de> <20191023123118.491328859@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191023123118.491328859@linutronix.de> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 23, 2019 at 02:27:14PM +0200, Thomas Gleixner wrote: > From: Thomas Gleixner > > Evaluating _TIF_NOHZ to decide whether to use the slow syscall entry path > is not only pointless, it's actually counterproductive: > > 1) Context tracking code is invoked unconditionally before that flag is > evaluated. > > 2) If the flag is set the slow path is invoked for nothing due to #1 > > Remove it. > > Signed-off-by: Thomas Gleixner I'm borrowing this patch for a series of mine. But if you apply it in the meantime, that would be even better :-) Thanks!