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=-0.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 B0358C433DB for ; Sun, 3 Jan 2021 21:22:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C21A2078D for ; Sun, 3 Jan 2021 21:22:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727655AbhACVWe (ORCPT ); Sun, 3 Jan 2021 16:22:34 -0500 Received: from mout.gmx.net ([212.227.15.18]:33321 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727414AbhACVWe (ORCPT ); Sun, 3 Jan 2021 16:22:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1609708839; bh=tyVCmIkoSkb6PtUj+JJ7qDitC2PSZFcvd9lmlSEV0is=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date; b=Z1Sk60CAPcnahBDZaxju+NP0wx7ogablHOH1s0JgFl0aQ4cdIkdZaEaQsLWZvPlBe Z58eBve6SYP1temTD7lrojEE5gv8KKvrYAZQsDfj2VcqH4dAVnStmAScTeofoJunGR 1PFTV+s229jrLDUT60p+x1zifZAiIyW/12CGS8Wo= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from chef ([212.114.250.16]) by mail.gmx.com (mrgmx004 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MbRk3-1kPb0Y1hrF-00bp1x; Sun, 03 Jan 2021 22:20:39 +0100 From: Julian Sax To: LKML Cc: x86@kernel.org, Thomas Gleixner , Alexandre Chartre , Peter Zijlstra , Paolo Bonzini , Julian Sax Subject: Bisected regression: /proc/stat reports 0 steal time after commit x86/kvm: Move context tracking where it belongs Date: Sun, 03 Jan 2021 22:20:25 +0100 Message-ID: <87a6tp3eg6.fsf@chef> MIME-Version: 1.0 Content-Type: text/plain X-Provags-ID: V03:K1:C7vWOWsmN4/4NbRjZl1+nH+GMFxBhdSMSP7tIJOWXJ4ulfL3bLy mVgcWMU0VvrGCDnyHdiJpt+FX0CdKYs+Kt5NtMWEXtfeh4koAg3efDQboDVtwP8FyZXkVIr MlLjH37256WpXxFPBr1EPwFaywOwVuLGsUmiJHECQQpy7wwmHiZg9QY2L+s2q+mv2E7Sb+3 8VQDlqmFT4TyobsAwE3tw== X-UI-Out-Filterresults: notjunk:1;V03:K0:eY/VC6+7ZaA=:Az4rvUmu7ncw4XQIseVZtB utC8mB2elgSP5Xn6I62Bw1LoPfyRxXKmYDHQH7pZetIUD/5P+d2811sghHvsRHz92CwBQ3ag7 1RICmWjFG+wwbAROSn1lh6aFqyFUs4GxjNzXuor1QJjQ389T2mr3BJmLYvd+UjinNQzKT6z2f fiYP7tazfj+fJGzpNaRxzaG+8YeQgGImRTSVVe605ovnuBmnz9UlO47l9FF/X3OBddVKMz34B q0GMJaxrS3CJBj3w4Mx47ex1h/xZTFek8Oz3fg+N24rcXILspUqEWBE+cDko426QPkovDCRCB 46h5SD5BwixKX/5mRwDCeEqh38naBNZpFS8lKYQOJUnJGd2G/h7v39MQxN7bHDiS+sIv7JnKo Tbf4j23Pts/OEW+kZaicGd7EeCa+jjr+VmO2qZzcEsa+Uyq6pd50uP5l8t77TQh9QP5/rXs1A lTWr3qkue7P2rNUsMoXBIq8bcjGfX1iio9OjcG/pmLQmdZtNVRFVPYRCvEoX599ps5k3zWCys yWlZThJF6NlDpKe9en+I1qgook0HbsNcE1qmG6mggi+D8frTKOp90JpTC4OY7lUs1VDggAO9p xkgUN8YLYD5l9anMMs3B5N56kdz1tXbY8TSpshx2YqzZVsX6JXDT9OoxLz0YIWM75wZPc/nb7 IiHaHOb07DiIvM3m5hYAoi7kRZxB+HJvghvMyYJdZGvT85+xpD0iFabtl724+HhWL29V9pDdT YYQgLV+guBXlakAzSI3x/HWCDFkNGsE1V48ClF4YVrEGN1KyC4yy9MUw/rut/fcF4Hp3Pxi4b 1+3zyaAuawDgaPwBq/c1nZ4VetLdSeVfdzHwjNz+9sqH0xiQ7WcYFaMNTk+XRgg24xcr6c+lC 1mqw234NiPb7UcO3c5BQ== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, I know I am kind of late with this report, but I recently upgraded from Kernel 5.8 to 5.10 and noticed that all my steal cpu time in htop was gone, instead the time seems to be added to the sys counter. The same thing happened in my own scripts, which source from /proc/stat. After execution of "qemu-system-x86_64 -enable-kvm -m 1G" right after bootup with no kvm used before this happens: 5.8, good julian@chef:~$ cat /proc/stat | grep "cpu " cpu 11235 3 7928 1309820 1360 0 64 0 508 0 # ^ steal 5.10, bad julian@chef:~$ cat /proc/stat | grep "cpu " cpu 420 0 1869 37801 746 0 7 0 0 0 # ^ steal I did bisect the problem and ended up at commit 87fa7f3e98a1310ef1ac1900e7ee7f9610a038bc Author: Thomas Gleixner Date: Wed Jul 8 21:51:54 2020 +0200 x86/kvm: Move context tracking where it belongs This however does not revert at all on top of the current HEAD and I am not familiar enough with the area to possibly guess what side effect could have caused this. This functionality was pretty nice, because it enabled me to see how the guest was scheduling etc. It would be nice if that could be brought back. Or am I doing the wrong thing to begin with? But then again, htop breaks in the same way. Thanks! Regards, Julian