Received: by 2002:ac0:a594:0:0:0:0:0 with SMTP id m20-v6csp680096imm; Wed, 23 May 2018 03:56:16 -0700 (PDT) X-Google-Smtp-Source: AB8JxZomwJIioGjWluqhuAon9LGyh3sx38dQ0uI0ruO39nZc3eyBPUzBdY+4fKH+/rtXbYX5iSKY X-Received: by 2002:a63:a411:: with SMTP id c17-v6mr1915627pgf.110.1527072976444; Wed, 23 May 2018 03:56:16 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1527072976; cv=none; d=google.com; s=arc-20160816; b=Hmm2HNmFS1wevOcKugtEingepsOn26KsM4COY7e721wZP8yNc/2DuhECoC2JW3J5cF MQnqNxJR8uEyOkAfqyWET34bpFLWlOIlTXCBGDoES1DOUDnwNDTJNxFWJ4q4BlIYo2rB g8v/p7/JN0/YFEmfVzadmd4q0PVHztTbkOL5QzSewgi3cL/sRnwQe/62thoET4vqcZ4y NElhpnobbYK1BWAhpvq5yBBHNbMrfwFynuNLHgv0l1HcHfIh2oSBr9TRR+vFWSZND3pW Q4vi9nM6PriPxX1WO13RfxcX6qS9KIk1eVV5SD4u1YO7DqcfkBCONIgY8+tprM4hMDyt Rn3w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=AHWCEv94kyRzuURyxSLtPmrYt3oiwCEZnYQt/jkGGYY=; b=dpsmKTIMyesKNXd8HUtt7hMJ6X2nK4A9IAM33IMQ2dh4iNP7TwL8yuMcpNnQF70dYT Bx7uF7pqohHAPDhbyVeQJ5x9ZjnRQw7Gnd+L1SaloKvgv7zCyEJl7kbEe/K2Vn/kiIky SYbdSHLyHF2j4EPchBFfXxi7q1Bx0B34OsyaPVGRg4Alzt0lY9R2ixo6hONltuXroepz 4kHivzOZUg4+W/cb1mUAP/5GrGSWEJ3TvuBoja3PakPxEZ1AavcM8i88W4gBgbejJQw6 0/kiZdS0A0J71hvbyM02kAbouxx7Set5UWZ5buI7Jlg5b1Bjn6wEk5ltMNFtwHYDOCp9 y2tA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id o7-v6si14311801pgp.525.2018.05.23.03.56.01; Wed, 23 May 2018 03:56:16 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932532AbeEWKxJ (ORCPT + 99 others); Wed, 23 May 2018 06:53:09 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:37782 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932391AbeEWKxE (ORCPT ); Wed, 23 May 2018 06:53:04 -0400 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id 1F53280549; Wed, 23 May 2018 12:53:03 +0200 (CEST) Date: Wed, 23 May 2018 12:53:02 +0200 From: Pavel Machek To: Christian =?iso-8859-1?Q?Kr=FCger?= Cc: linux-kernel@vger.kernel.org Subject: Re: Suggestion: =?utf-8?B?4oCec3BlY3RyZV92?= =?utf-8?B?Mj1vZmbigJwgYW5kIOKAnm5vcHRp?= =?utf-8?B?4oCc?= per default in "Intel Atom N270" case? Message-ID: <20180523105302.GE15312@amd> References: <72a7122d-0020-f307-a76d-bb80a2c19842@web.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="M/SuVGWktc5uNpra" Content-Disposition: inline In-Reply-To: <72a7122d-0020-f307-a76d-bb80a2c19842@web.de> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --M/SuVGWktc5uNpra Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat 2018-05-19 21:53:02, Christian Kr=FCger wrote: > Hi, >=20 > Since the old "in-order-execution" Intel CPUs like the Intel Atom N270 > (known for being installed in many Netbooks and Nettops) are not sensitive > for "Meltdown" & "Spectre" , wouldn't it be a good idea to exclude these > anyway "weak" CPUs from the costly patches by default? >=20 > Browsing the web, I can "feel the difference" if the matching kernel opti= ons > are applied on such a device. Can you also measure the difference? Placebo effect is hard to avoid. But yes, we do not need to do workarounds on non-buggy machines... Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --M/SuVGWktc5uNpra Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlsFSA4ACgkQMOfwapXb+vJCPACgjUfIt4MrQuWRA1SL/d72GEby YGsAnjDf0q57pK4WO8YDjYiikKjcyxXf =Ivix -----END PGP SIGNATURE----- --M/SuVGWktc5uNpra--