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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 99868C43331 for ; Wed, 25 Mar 2020 14:28:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65C2120A8B for ; Wed, 25 Mar 2020 14:28:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DwAtTY5F" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727650AbgCYO2w (ORCPT ); Wed, 25 Mar 2020 10:28:52 -0400 Received: from us-smtp-delivery-74.mimecast.com ([216.205.24.74]:27994 "EHLO us-smtp-delivery-74.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727580AbgCYO2v (ORCPT ); Wed, 25 Mar 2020 10:28:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585146530; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=JqpwltFL/SwS1UhlcIi0MOoODF8Cpbq1cMt7ik4CiTE=; b=DwAtTY5FeL0l8g+pWuXvopKrrWYucGwQwduc1nrTtQ7hq6MspeALe2jGt6nVSw8qaYyb9K ynUd0CYmDS2h3vCjpFRhJeOex/BfNvmOWD6bkl/6GbbKsREAF1yXrgHu0AK2BRWP1/GPvY QPCJc3XcoxB2PUzEq+tApe7GKI40wDE= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-153-f2Yi36SIPoqF5IrmnpfLjw-1; Wed, 25 Mar 2020 10:28:49 -0400 X-MC-Unique: f2Yi36SIPoqF5IrmnpfLjw-1 Received: by mail-wm1-f70.google.com with SMTP id 2so957631wmf.1 for ; Wed, 25 Mar 2020 07:28:48 -0700 (PDT) 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:in-reply-to:references:date :message-id:mime-version; bh=JqpwltFL/SwS1UhlcIi0MOoODF8Cpbq1cMt7ik4CiTE=; b=Pz48DXrEngjv439YH0xo7Ys+f/9C+gBzipQ2aS5nkWp+dKoKInyWrU90zwTEnaa3TD qGOEp7eusHaF7eNALpXkfhob5RzhCguKDcpK6lkvAiiaDAwpko87shPj+tXoq41CB9R6 3ufazYU1NVyLg0O/41Xzhl24C543Fxqj9SPEl+4orWgssNWt9ngSftZsOsSsSfDJU5Mm CKgXzNEkw5PCasVCbbdJyValT8JMoJYKhnUmU9j9eCSIoKkKz+4Oowk2AZ7Wa40x+BQV yIJDt5lmDpYX7Wfx8WoNoTDIdqQJf4MIUMuc7yE+86XpaUggN3RQ3R4DQzvIy5g0r2kT v4Jg== X-Gm-Message-State: ANhLgQ0cSkVYnaTdDh5YTkWg0tfTCgxG5xrekgPMs4JzlQs1WgudZ/f+ bX06YrCAW+HyZ6t+e4amC85uw/YNxuq9Ec9LOTW5QYAp8is04CCTrytUgI+d7W6nA3ArFhjGk4G 7LG75R02njwneHxwctHN8Zo7g X-Received: by 2002:a7b:c050:: with SMTP id u16mr4024616wmc.68.1585146527996; Wed, 25 Mar 2020 07:28:47 -0700 (PDT) X-Google-Smtp-Source: ADFU+vtps1lqlEjeVqhmoxqx06a7QnIYlVTNWJazZkk/ssQW3dTzHNkG7M+s2wksPvvsb7XCMHkt2A== X-Received: by 2002:a7b:c050:: with SMTP id u16mr4024590wmc.68.1585146527811; Wed, 25 Mar 2020 07:28:47 -0700 (PDT) Received: from vitty.brq.redhat.com (g-server-2.ign.cz. [91.219.240.2]) by smtp.gmail.com with ESMTPSA id v7sm9590018wml.18.2020.03.25.07.28.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Mar 2020 07:28:47 -0700 (PDT) From: Vitaly Kuznetsov To: Tianyu Lan Cc: Yubo Xie , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Tianyu Lan , kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, liuwe@microsoft.com, daniel.lezcano@linaro.org, tglx@linutronix.de, michael.h.kelley@microsoft.com Subject: Re: [PATCH] x86/Hyper-V: Fix hv sched clock function return wrong time unit In-Reply-To: <039e126f-f00d-d7e1-aa92-c049c9e3333b@gmail.com> References: <20200324151935.15814-1-yuboxie@microsoft.com> <87ftdx7nxv.fsf@vitty.brq.redhat.com> <039e126f-f00d-d7e1-aa92-c049c9e3333b@gmail.com> Date: Wed, 25 Mar 2020 15:28:45 +0100 Message-ID: <87lfno5x0i.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-hyperv-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org Tianyu Lan writes: >>> @@ -398,7 +399,8 @@ static u64 notrace read_hv_clock_msr_cs(struct clocksource *arg) >>> >>> static u64 read_hv_sched_clock_msr(void) >>> { >>> - return read_hv_clock_msr() - hv_sched_clock_offset; >>> + return (read_hv_clock_msr() - hv_sched_clock_offset) >>> + * (NSEC_PER_SEC / HV_CLOCK_HZ); >>> } >> >> kvmclock seems to have the same (pre-patch) code ... > > > kvm sched clock gets time from pvclock_clocksource_read() and > the time unit is nanosecond. So there is such issue in KVM code. > Ah, true, kvmclock is always 1Ghz so it's reading 'naturally' converts to ns. -- Vitaly