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=-6.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 0E4C0C388F9 for ; Wed, 11 Nov 2020 21:10:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8253F208B3 for ; Wed, 11 Nov 2020 21:10:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="w+W2Yhg8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726299AbgKKVKl (ORCPT ); Wed, 11 Nov 2020 16:10:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725933AbgKKVKk (ORCPT ); Wed, 11 Nov 2020 16:10:40 -0500 Received: from mail-qt1-x842.google.com (mail-qt1-x842.google.com [IPv6:2607:f8b0:4864:20::842]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9902BC0613D1 for ; Wed, 11 Nov 2020 13:10:40 -0800 (PST) Received: by mail-qt1-x842.google.com with SMTP id 3so2428061qtx.3 for ; Wed, 11 Nov 2020 13:10:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=DwowmHeOF5hB8SgYxSfDIWmDR6goWK654K10ZP4Xiw0=; b=w+W2Yhg8OjZUUrqe7AlCDU6t7QJJRytmKewAlGJCJCXZs1zV5UXCfTAvjpY4bKxswm K4KBoy+Uelnxh14Dv8DOvsTsWhK97XfKECHmUIz7oOO6tQCFLVYNMyZx+l1xpPZVb8Hg TxZXSBk/jSOczSRxBiHH5dKJZ2NuTVepCwzmg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=DwowmHeOF5hB8SgYxSfDIWmDR6goWK654K10ZP4Xiw0=; b=eB+wkYzoVFBIp58tCI2vsiIGyW5MZf++dNHhtnfQqj8Bcx4uGoUGiLwHs9p71RVWjU MdpH74K45oD4al3ieaolTc1JNIuNkBLPXPqVQyr8XkGWEfSeMMaiy9MmV6E4xvTJkd18 Ic2g3JMdKTFCeRO2ZHbk2JY7F6W/Xdfz8Nhg377vciY3cIytbWhFDHnOU6xJDYvE+7By +R8tRVCZNj9UME+H3ffYyoiDWXUoBut7BK2Lo1vgG6KWQbWlDrj1Q340J5dtm2ToVjBh p8CkXNpdyOz7vMsNwUNRp6PMDkFxojuKHsPuYRm8oSq5ZD6JO4nG8BIpV0dzV+0a9dOh 0VDw== X-Gm-Message-State: AOAM530CAvrJeu8tIrylAMuye+P/ZUU/LflijsVYMrsVbVh/t3AKGK/c PAPgA/t0QO89paotmpGXgf0MeQ== X-Google-Smtp-Source: ABdhPJzUmqR7UaXA+izOB79g+2RYT1W1/HkLbohcVWdJ8v1xStGJsQKzBWVm1aSoAtA6Af09oJf8yA== X-Received: by 2002:ac8:5557:: with SMTP id o23mr24766068qtr.252.1605129039714; Wed, 11 Nov 2020 13:10:39 -0800 (PST) Received: from joelaf.cam.corp.google.com ([2620:15c:6:411:cad3:ffff:feb3:bd59]) by smtp.gmail.com with ESMTPSA id d66sm2112389qke.132.2020.11.11.13.10.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Nov 2020 13:10:39 -0800 (PST) From: "Joel Fernandes (Google)" To: Nishanth Aravamudan , Julien Desfossez , Peter Zijlstra , Tim Chen , Vineeth Pillai , Aaron Lu , Aubrey Li , tglx@linutronix.de, linux-kernel@vger.kernel.org Cc: mingo@kernel.org, torvalds@linux-foundation.org, fweisbec@gmail.com, keescook@chromium.org, kerrnel@google.com, Phil Auld , Valentin Schneider , Mel Gorman , Pawan Gupta , Paolo Bonzini , joel@joelfernandes.org, vineeth@bitbyteword.org, Chen Yu , Christian Brauner , Agata Gruza , Antonio Gomez Iglesias , graf@amazon.com, konrad.wilk@oracle.com, dfaggioli@suse.com, pjt@google.com, rostedt@goodmis.org, derkling@google.com, benbjiang@tencent.com, Alexandre Chartre , James.Bottomley@hansenpartnership.com, OWeisse@umich.edu, Dhaval Giani , Junaid Shahid , jsbarnes@google.com, chris.hyser@oracle.com, Ben Segall , Josh Don , Hao Luo , amistry@google.com, Borislav Petkov , Daniel Bristot de Oliveira , Dietmar Eggemann , "H. Peter Anvin" , Ingo Molnar , Juri Lelli , Mel Gorman , Mike Rapoport , thomas.lendacky@amd.com, Tony Luck , Vincent Guittot , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)) Subject: [RFC 0/2] Do not slow down some AMD devices with coresched Date: Wed, 11 Nov 2020 16:10:09 -0500 Message-Id: <20201111211011.1381848-1-joel@joelfernandes.org> X-Mailer: git-send-email 2.29.2.222.g5d2a92d10f8-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Here are 2 patches I am thinking of sending with next coresched series. Let me know what you think. These are for not slowing down certain AMD devices if they don't have vulnerabilities that require coresched. 1/2 - keep coresched disabled if device doesn't have vulnerability. 2/2 - add debug information. In the future, if needed we could add more options to make it possible to force-enable coresched. But right now I don't see a need for that, till a usecase arises. Joel Fernandes (Google) (2): x86/bugs: Disable coresched on hardware that does not need it sched/debug: Add debug information about whether coresched is enabled arch/x86/kernel/cpu/bugs.c | 8 ++++++++ kernel/sched/core.c | 7 +++++++ kernel/sched/debug.c | 4 ++++ kernel/sched/sched.h | 5 +++++ 4 files changed, 24 insertions(+) -- 2.29.2.222.g5d2a92d10f8-goog