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=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 3A5D9C433E0 for ; Thu, 14 May 2020 16:51:43 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 00EBD2065F for ; Thu, 14 May 2020 16:51:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="Sm8Nuuy8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 00EBD2065F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jZH4t-0000nr-GT; Thu, 14 May 2020 16:51:23 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jZH4s-0000nm-JA for xen-devel@lists.xenproject.org; Thu, 14 May 2020 16:51:22 +0000 X-Inumbo-ID: 23861656-9603-11ea-ae69-bc764e2007e4 Received: from esa1.hc3370-68.iphmx.com (unknown [216.71.145.142]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 23861656-9603-11ea-ae69-bc764e2007e4; Thu, 14 May 2020 16:51:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1589475082; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=Pp8JbQ9QRaQeKFHCajjGtu3O0dsndqmSPyyTnO6uZcM=; b=Sm8Nuuy8tsaZjklU/2xL1TWnbIJVQ+BM6rAevG3p4OkJi1+2bL1u7crn /W05vWopFGlIPoBu+gMjhLhhbmMn4h2mmZcTB3oN2gRMDIBsotqpC65SE 2iyzlUK3aVwIbwdddWnld8aWZl7NkiS468953g7m07XTcBs3acY3ftKLz o=; Received-SPF: None (esa1.hc3370-68.iphmx.com: no sender authenticity information available from domain of roger.pau@citrix.com) identity=pra; client-ip=162.221.158.21; receiver=esa1.hc3370-68.iphmx.com; envelope-from="roger.pau@citrix.com"; x-sender="roger.pau@citrix.com"; x-conformance=sidf_compatible Received-SPF: Pass (esa1.hc3370-68.iphmx.com: domain of roger.pau@citrix.com designates 162.221.158.21 as permitted sender) identity=mailfrom; client-ip=162.221.158.21; receiver=esa1.hc3370-68.iphmx.com; envelope-from="roger.pau@citrix.com"; x-sender="roger.pau@citrix.com"; x-conformance=sidf_compatible; x-record-type="v=spf1"; x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133 ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4 ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88 ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83 ip4:168.245.78.127 ~all" Received-SPF: None (esa1.hc3370-68.iphmx.com: no sender authenticity information available from domain of postmaster@mail.citrix.com) identity=helo; client-ip=162.221.158.21; receiver=esa1.hc3370-68.iphmx.com; envelope-from="roger.pau@citrix.com"; x-sender="postmaster@mail.citrix.com"; x-conformance=sidf_compatible Authentication-Results: esa1.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none; spf=None smtp.pra=roger.pau@citrix.com; spf=Pass smtp.mailfrom=roger.pau@citrix.com; spf=None smtp.helo=postmaster@mail.citrix.com; dmarc=pass (p=none dis=none) d=citrix.com IronPort-SDR: FxyjoXYK6n85q4eEjwyYYn3JqDvM/CftwFVJoxjN67Wex22QrFtaduzZOaRxi91vu2/29fQLKX QAvlxjSB/fM+B+zElyLuzixJVjZt7qeJ+IH0+UhkTQdR2AAyGxkyJVmYsKvoah99pc7e0t0yB2 vY05jaDjOFkFACsA2R7dTsE+gxSOidJ7/y7aA8u6afRcvew8VyV2WoU6YIhlYneqMGj19X+HWh IqpHYTR2ZLOllCh2WeorrreQngHio+zDA2QX/cmupdkErBOt+UPjD5MbIkHyQqfVyiOfl8RQAs 4fU= X-SBRS: 2.7 X-MesageID: 17818899 X-Ironport-Server: esa1.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.73,392,1583211600"; d="scan'208";a="17818899" Date: Thu, 14 May 2020 18:51:12 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Jan Beulich Subject: Re: [PATCH] x86: retrieve and log CPU frequency information Message-ID: <20200514165112.GL54375@Air-de-Roger> References: <1fd091d2-30e2-0691-0485-3f5142bd457f@suse.com> <20200514131021.GB54375@Air-de-Roger> <2e9c7c05-e42c-52d4-f48c-9ecc8b14a1a7@suse.com> <20200514153252.GE54375@Air-de-Roger> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: AMSPEX02CAS01.citrite.net (10.69.22.112) To AMSPEX02CL02.citrite.net (10.69.22.126) X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: "xen-devel@lists.xenproject.org" , Wei Liu , Andrew Cooper Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On Thu, May 14, 2020 at 05:50:29PM +0200, Jan Beulich wrote: > [CAUTION - EXTERNAL EMAIL] DO NOT reply, click links, or open attachments unless you have verified the sender and know the content is safe. > > On 14.05.2020 17:32, Roger Pau Monné wrote: > > On Thu, May 14, 2020 at 03:38:18PM +0200, Jan Beulich wrote: > >> On 14.05.2020 15:10, Roger Pau Monné wrote: > >>> On Wed, Apr 15, 2020 at 01:55:24PM +0200, Jan Beulich wrote: > >>>> While from just a single Skylake system it is already clear that we > >>>> can't base any of our logic on CPUID leaf 15 [1] (leaf 16 is > >>>> documented to be used for display purposes only anyway), logging this > >>>> information may still give us some reference in case of problems as well > >>>> as for future work. Additionally on the AMD side it is unclear whether > >>>> the deviation between reported and measured frequencies is because of us > >>>> not doing well, or because of nominal and actual frequencies being quite > >>>> far apart. > >>> > >>> Can you add some reference to the AMD implementation? I've looked at > >>> the PMs and haven't been able to find a description of some of the > >>> MSRs, like 0xC0010064. > >> > >> Take a look at > >> > >> https://developer.amd.com/resources/developer-guides-manuals/ > >> > >> I'm unconvinced a reference needs adding here. > > > > Do you think it would be sensible to introduce some defines for at > > least 0xC0010064? (ie: MSR_AMD_PSTATE_DEF_BASE) > > > > I think it would make it easier to find on the manuals. > > I did consider doing so at the time, but dropped the idea as we have > a few more examples where we use bare MSR numbers when they're used > just once or very rarely. What I'm not sure about is whether the > name would help finding the doc - the doc is organized by MSR number > after all. I would prefer if we add names as much as possible, as I think it makes the code easier to understand, but I can also see the point of that being more churn as you have to end up looking at the manual to see exactly what each MSR contains anyway. FTR, I wasn't finding the MSR in the AMD docs because I was searching as C0010064 when I should be instead using C001_0064. Thanks, Roger.