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_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 3AAD3C433E0 for ; Thu, 14 May 2020 15:11:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 051F5205CB for ; Thu, 14 May 2020 15:11:48 +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="q6Aij/a0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727926AbgENPLr (ORCPT ); Thu, 14 May 2020 11:11:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726550AbgENPLq (ORCPT ); Thu, 14 May 2020 11:11:46 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C2F1C061A0C for ; Thu, 14 May 2020 08:11:46 -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-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=NBNcKq7QYzrg1uKWtIz2EqtZTFuMJnDm85WUYzbR/G8=; b=q6Aij/a08HABfbtl8iagxjFNDq Yjp5v2qGISczJfPFEfDeeD0zYujKyHomxE3TQO5JrYt8DP4WInPuDXaqT6gvruxFSu14xmYGvTKd3 CwvzFGHPbVXINCLJ6PsUbbTFvnBE1I6gqxTbwBsRwGYfzrn1HHwI3my9wyEscLmCqPZieV9PIDm+a CMDzuOQc4B4W6zXaNerKnnqj+Y19hVSy7KisMOo54KoW1Fsw4t56Iic1p8LK3VAvJMYyvgEnrwy9V FIExz9saX8LEPOBnxxF7WtmBsVzLEIuuifI/RSQFyNUeMtMe+gs4YicW9HTDBhJmPs7euzFtlwOjY rW59wlBw==; 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 1jZFVW-0002QI-Fv; Thu, 14 May 2020 15:10:46 +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 236653062BA; Thu, 14 May 2020 17:10:43 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 156262B870EB1; Thu, 14 May 2020 17:10:43 +0200 (CEST) Date: Thu, 14 May 2020 17:10:43 +0200 From: Peter Zijlstra To: Andy Lutomirski Cc: Thomas Gleixner , Andy Lutomirski , LKML , X86 ML , "Paul E. McKenney" , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon Subject: Re: [patch V4 part 4 02/24] x86/int3: Avoid atomic instrumentation Message-ID: <20200514151043.GD2978@hirez.programming.kicks-ass.net> References: <878shuzhcx.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 14, 2020 at 08:08:46AM -0700, Andy Lutomirski wrote: > Alternatives should be valid regardless. Isn’t the world essentially stopped while we apply them? Yes, we do that before we go SMP.