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 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8DBACC433F5 for ; Thu, 16 Dec 2021 16:47:25 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.248105.427932 (Exim 4.92) (envelope-from ) id 1mxtuS-0006pR-AJ; Thu, 16 Dec 2021 16:47:12 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 248105.427932; Thu, 16 Dec 2021 16:47:12 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mxtuS-0006pK-6r; Thu, 16 Dec 2021 16:47:12 +0000 Received: by outflank-mailman (input) for mailman id 248105; Thu, 16 Dec 2021 16:47:11 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mxtuQ-0006RG-Vr for xen-devel@lists.xenproject.org; Thu, 16 Dec 2021 16:47:10 +0000 Received: from ppsw-43.csi.cam.ac.uk (ppsw-43.csi.cam.ac.uk [131.111.8.143]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id cef113d7-5e8f-11ec-85d3-df6b77346a89; Thu, 16 Dec 2021 17:47:09 +0100 (CET) Received: from hades.srcf.societies.cam.ac.uk ([131.111.179.67]:47092) by ppsw-43.csi.cam.ac.uk (ppsw.cam.ac.uk [131.111.8.139]:25) with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) id 1mxtuO-000sSc-ne (Exim 4.95) (return-path ); Thu, 16 Dec 2021 16:47:08 +0000 Received: from [192.168.1.10] (host-92-12-61-86.as13285.net [92.12.61.86]) (Authenticated sender: amc96) by hades.srcf.societies.cam.ac.uk (Postfix) with ESMTPSA id 21BBA1FA9B; Thu, 16 Dec 2021 16:47:08 +0000 (GMT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: cef113d7-5e8f-11ec-85d3-df6b77346a89 X-Cam-AntiVirus: no malware found X-Cam-ScannerInfo: https://help.uis.cam.ac.uk/email-scanner-virus Message-ID: <430620c8-2181-296f-6fe6-bc83d86114c8@srcf.net> Date: Thu, 16 Dec 2021 16:47:07 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.4.0 Subject: Re: [PATCH v2 2/4] x86/cpuid: Factor common parsing out of parse_xen_cpuid() Content-Language: en-GB To: Jan Beulich , Andrew Cooper Cc: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Wei Liu , Xen-devel References: <20211215222115.6829-1-andrew.cooper3@citrix.com> <20211215222115.6829-3-andrew.cooper3@citrix.com> <49a6035e-9291-7a67-ad78-be6ebde79def@suse.com> From: Andrew Cooper In-Reply-To: <49a6035e-9291-7a67-ad78-be6ebde79def@suse.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 16/12/2021 16:41, Jan Beulich wrote: > On 15.12.2021 23:21, Andrew Cooper wrote: >> dom0-cpuid= is going to want to reuse the common parsing loop, so factor it >> out into parse_cpuid(). >> >> Irritatingly, despite being static const, the features[] array gets duplicated >> each time parse_cpuid() is inlined. As it is a large (and ever growing with >> new CPU features) datastructure, move it to being file scope so all inlines >> use the same single object. >> >> No functional change. >> >> Signed-off-by: Andrew Cooper > Reviewed-by: Jan Beulich Thanks. > >> We probably want to be wary of fallout from this pattern elsewhere. I only >> noticed it by chance. > While that sounds at least close to a bug, there might by some subtle reason > for why they have to do it that way. Now I've thought about this more, probably C's "every object has a unique address" rule. ~Andrew