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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7837FC433B4 for ; Sun, 2 May 2021 18:37:59 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 24AC5611CB for ; Sun, 2 May 2021 18:37:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24AC5611CB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47464 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ldGyc-0003DU-7A for qemu-devel@archiver.kernel.org; Sun, 02 May 2021 14:37:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53826) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ldGi3-0004t7-V9 for qemu-devel@nongnu.org; Sun, 02 May 2021 14:20:51 -0400 Received: from indium.canonical.com ([91.189.90.7]:44734) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ldGhz-0006A0-Lr for qemu-devel@nongnu.org; Sun, 02 May 2021 14:20:51 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1ldGhx-0000Ph-RU for ; Sun, 02 May 2021 18:20:45 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id CDCAD2E815D for ; Sun, 2 May 2021 18:20:45 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Sun, 02 May 2021 18:14:11 -0000 From: Thomas Huth <1856335@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Incomplete; importance=Undecided; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: babumoger djdatte h-sieger janklos sanjaybmd th-huth X-Launchpad-Bug-Reporter: Damir (djdatte) X-Launchpad-Bug-Modifier: Thomas Huth (th-huth) References: <157625616239.22064.10423897892496347105.malonedeb@gac.canonical.com> Message-Id: <161997925140.9976.6807814210753165762.malone@gac.canonical.com> Subject: [Bug 1856335] Re: Cache Layout wrong on many Zen Arch CPUs X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="02afa4875ac52c169f5cddf0d1bcdd6e149a3754"; Instance="production" X-Launchpad-Hash: e854279281bcc416b78855bbbb94ff5d4e066c42 Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -66 X-Spam_score: -6.7 X-Spam_bar: ------ X-Spam_report: (-6.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1856335 <1856335@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The QEMU project is currently considering to move its bug tracking to another system. For this we need to know which bugs are still valid and which could be closed already. Thus we are setting older bugs to "Incomplete" now. If you still think this bug report here is valid, then please switch the state back to "New" within the next 60 days, otherwise this report will be marked as "Expired". Or please mark it as "Fix Released" if the problem has been solved with a newer version of QEMU already. Thank you and sorry for the inconvenience. ** Changed in: qemu Status: New =3D> Incomplete -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1856335 Title: Cache Layout wrong on many Zen Arch CPUs Status in QEMU: Incomplete Bug description: AMD CPUs have L3 cache per 2, 3 or 4 cores. Currently, TOPOEXT seems to always map Cache ass if it was an 4-Core per CCX CPU, which is incorrect, and costs upwards 30% performance (more realistically 10%) in L3 Cache Layout aware applications. Example on a 4-CCX CPU (1950X /w 8 Cores and no SMT): =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0EPYC-IBPB =C2=A0=C2=A0=C2=A0=C2=A0AMD =C2=A0=C2=A0=C2=A0=C2=A0 In windows, coreinfo reports correctly: ****---- Unified Cache 1, Level 3, 8 MB, Assoc 16, LineSize 64 ----**** Unified Cache 6, Level 3, 8 MB, Assoc 16, LineSize 64 On a 3-CCX CPU (3960X /w 6 cores and no SMT): =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0EPYC-IBPB =C2=A0=C2=A0=C2=A0=C2=A0AMD =C2=A0=C2=A0=C2=A0=C2=A0 in windows, coreinfo reports incorrectly: ****-- Unified Cache 1, Level 3, 8 MB, Assoc 16, LineSize 64 ----** Unified Cache 6, Level 3, 8 MB, Assoc 16, LineSize 64 Validated against 3.0, 3.1, 4.1 and 4.2 versions of qemu-kvm. With newer Qemu there is a fix (that does behave correctly) in using the = dies parameter: =C2=A0 The problem is that the dies are exposed differently than how AMD does it natively, they are exposed to Windows as sockets, which means, that if you are nto a business user, you can't ever have a machine with more than two CCX (6 cores) as consumer versions of Windows only supports two sockets. (Should this be reported as a separate bug?) To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1856335/+subscriptions