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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7360C433F5 for ; Mon, 14 Mar 2022 17:52:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243485AbiCNRxZ (ORCPT ); Mon, 14 Mar 2022 13:53:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232787AbiCNRxW (ORCPT ); Mon, 14 Mar 2022 13:53:22 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 99ED513F2C for ; Mon, 14 Mar 2022 10:52:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647280331; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7PoYm4c24Q3JJh2lpWhFWRFLRzas/0vml62uEAb2M70=; b=QTBDcmY+laqqzEB8NMsN7E/TkbVMeP4ZZwkDx5g/m7b+tjyOe9io8N15v3rj4Y8FUPAPLC gnMtDcQSpt+Bnt0ZiQrB9AaMesJHzp2L9yFIcciTIYgtdpYcYplJlpLsjMRpy6hkNC9yKP oxHdzPan6omJtmVrnrAK4U8jz7Y1b/0= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-90-1EdAwJXiNVG2oqTBldw8_Q-1; Mon, 14 Mar 2022 13:52:10 -0400 X-MC-Unique: 1EdAwJXiNVG2oqTBldw8_Q-1 Received: by mail-wr1-f70.google.com with SMTP id y13-20020adfee0d000000b001f1fa450a3dso4686033wrn.11 for ; Mon, 14 Mar 2022 10:52:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=7PoYm4c24Q3JJh2lpWhFWRFLRzas/0vml62uEAb2M70=; b=Vmalxmt+DtF6NYe3pav/fucCeOi8RQpJBgv3ljc+Fh8AvSaHilb9h+kRfGS35AVRhC 9YXjPDB/EApvvTUHeMz8/5IJfa2gUOjCs6ozZw1pYwjEfANOHnDDVoNsNPRwj9y6Gfm3 7IJbQ9ZBCH8F3ibcjpeCsT6a+yHsZrJzit91s9y1Oj8XW7qpw7bpGEQ8Inr8XARvIgd+ JIJq/l8dYcoo0lEaQMJcul7grydEx5LL3c7Lon/vCR1ZGt0+SGOrvCiKHGTRwpJYldB/ jBrx3o84Uly58+FMWAgX3T14FLql7Vw3G+rg2SNZhksKg6QqNqvCUjf+e+B01Btrl2O9 0TfA== X-Gm-Message-State: AOAM532pcePrfPUNMoJ9vM5jp7H7DhSxc2CPmX3r+l3EYWSVVaHe4jD+ xc1JVSj286uRsU4CwRuh8k7lF/QqMmcAzRQPa1tvyZvgzyHMoBoMw93HmQWOgy6EIDQDU6Bz86R T6nOu2ntQlObMZkQuEgeLHU4P X-Received: by 2002:a05:6000:1448:b0:1f0:6620:968f with SMTP id v8-20020a056000144800b001f06620968fmr17876447wrx.714.1647280329106; Mon, 14 Mar 2022 10:52:09 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzO7a/vR6ZwBhjanEnZfZRofoAb4xNg0ErWA+say3xs9Cyy4NfYJHlDuNQt8RwO/jauBt0CRw== X-Received: by 2002:a05:6000:1448:b0:1f0:6620:968f with SMTP id v8-20020a056000144800b001f06620968fmr17876423wrx.714.1647280328797; Mon, 14 Mar 2022 10:52:08 -0700 (PDT) Received: from vian.redhat.com ([2a0c:5a80:3506:3400:69b5:c807:1d52:ff67]) by smtp.gmail.com with ESMTPSA id l13-20020a5d4bcd000000b001f0620ecb3csm13678781wrt.40.2022.03.14.10.52.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Mar 2022 10:52:08 -0700 (PDT) From: Nicolas Saenz Julienne To: feng.tang@intel.com, tglx@linutronix.de Cc: andi.kleen@intel.com, bp@alien8.de, dave.hansen@intel.com, hpa@zytor.com, len.brown@intel.com, linux-kernel@vger.kernel.org, mingo@redhat.com, paulmck@kernel.org, peterz@infradead.org, rui.zhang@intel.com, tim.c.chen@intel.com, x86@kernel.org, mtosatti@redhat.com, nsaenzju@redhat.com, frederic@kernel.org Subject: Re: [PATCH v3 1/2] x86/tsc: add a timer to make sure tsc_adjust is always checked Date: Mon, 14 Mar 2022 18:52:07 +0100 Message-Id: <20220314175207.274870-1-nsaenzju@redhat.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20211117023751.24190-1-feng.tang@intel.com> References: <20211117023751.24190-1-feng.tang@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Feng, Thomas, > On Wed, Nov 17, 2021 at 10:37:51AM +0800, Feng Tang wrote: > Normally the tsc_sync will get checked every time system enters idle state, > but Thomas Gleixner mentioned there is still a caveat that a system won't > enter idle [1], either because it's too busy or configured purposely to not > enter idle. Setup a periodic timer (every 10 minitues) to make sure the > check is always on. > > [1]. https://lore.kernel.org/lkml/875z286xtk.fsf@nanos.tec.linutronix.de/ > Signed-off-by: Feng Tang I can see this timer interrupting my system's nohz_full CPUs. It'd be nice to be able to avoid the noise. A solution is using 'tsc=reliable', but IIUC this is not what the flag was created for. Any ideas/suggestions? Regards, Nicolas