Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757120Ab2ENQQM (ORCPT ); Mon, 14 May 2012 12:16:12 -0400 Received: from mga03.intel.com ([143.182.124.21]:30895 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757097Ab2ENQQH (ORCPT ); Mon, 14 May 2012 12:16:07 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="99899007" From: "Luck, Tony" To: Borislav Petkov CC: "linux-kernel@vger.kernel.org" , Ingo Molnar , Chen Gong , "Huang, Ying" , Hidetoshi Seto Subject: RE: [PATCH 1/2] x86/mce: Only restart instruction after machine check recovery if it is safe Thread-Topic: [PATCH 1/2] x86/mce: Only restart instruction after machine check recovery if it is safe Thread-Index: AQHNMO8MV8VH9kbX5E+oEyS4j60vMJbJdKrg Date: Mon, 14 May 2012 16:16:05 +0000 Message-ID: <3908561D78D1C84285E8C5FCA982C28F192EED2B@ORSMSX104.amr.corp.intel.com> References: <20120513095913.GB28863@aftab.osrc.amd.com> In-Reply-To: <20120513095913.GB28863@aftab.osrc.amd.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.22.254.139] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id q4EGGP38004398 Content-Length: 880 Lines: 20 >> + int restartable; > > Is it me or does this look like a flag, or a bitfield? Instead of > wasting a whole integer for a single bit of information. I could make it "int flags;" and "#define MCE_INFO_RESTARTABLE 1" to make it clear that we have lots more bits available for special cases? > It will probably end up the same size though due to compiler padding > since this struct is currently 4 + 2*8 byte without the ->restartable > thing. Yup - we can't save any memory (unless we introduce more complexity to the code ... low PAGE_SHIFT bits of the "paddr" field are simply thrown away ... so we could allocate a bit there ... but I don't think that the resulting ugliness is worth the memory savings). -Tony ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?