Received: by 2002:a25:868d:0:0:0:0:0 with SMTP id z13csp1407800ybk; Thu, 14 May 2020 08:15:49 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwr/jR2fD6u/GcGzdcJSvVsVQmRL4L3aZR6J7Ey65stVcItCK8u5egEuO3DIzvgKkQutiRj X-Received: by 2002:a50:8d57:: with SMTP id t23mr4503164edt.168.1589469348837; Thu, 14 May 2020 08:15:48 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1589469348; cv=none; d=google.com; s=arc-20160816; b=K0wLJlF6BUgcIv/d28szitsEjIH8NyuBOknHutXhErlWAqNnwtesbLj/UPBiUpFrpu Fxa57znJSW7IHZzrkEOUqNhQxD1e5x4nzmxgQq8dCZElNp5XiGFglfV3Gz+vGKu5PBdI H7NGorB94pfzWPDFfaS2pZE6Uj9RyQygut5OgO6w3BvchI0dXj7E2gLtqq5IQlL89NR2 lDm8qLkhsjbaXolFup7hTCI+Rr8d0BAB3VdncFSnxZXCMqCQRPfyjUIFbjoPD4mfEyBM d0tcf8bKrvhdmGM6z9t76K9erlAr4hFzg7nU48/+CHD2paek2jotGrwxZlIsvkyaTL4g qvCA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:in-reply-to:content-transfer-encoding :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature; bh=NBNcKq7QYzrg1uKWtIz2EqtZTFuMJnDm85WUYzbR/G8=; b=wJ47Jgzw7egAoRDL6PvCMKJlsh8pvK80CoT4eFLW2gWbFPCL9T5zIK95DnUE/fAXRl pM0TQHf+LgvbKLn2cCDt85HxUj1bCj/q9w4L0pk85HJ/qoFOCy1WXxLlRDKDy0wKD1qN l9DdOJNkLjcWLY0bAkDCjptRCpG7ynhN+Gs4FSLcPFjz3l7MmL7ldYbFR95kQd08hsEg N0oy35t4BKI+enL2UO8HmTPpYjV1CDUluVKfENQ0LRPBEdgrloSj2FlFmullZruzRocF yuFxtgQKkO5tnQqiAf4aCygT37Cs8TpkvQxDDSady343yXI+iFDYw6uKOskVoZotz2Yf aXxw== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@infradead.org header.s=merlin.20170209 header.b="q6Aij/a0"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id q23si1760120edg.593.2020.05.14.08.15.24; Thu, 14 May 2020 08:15:48 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=merlin.20170209 header.b="q6Aij/a0"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727899AbgENPLr (ORCPT + 99 others); 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.