From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754927Ab1KUVkh (ORCPT ); Mon, 21 Nov 2011 16:40:37 -0500 Received: from fmmailgate07.web.de ([217.72.192.248]:58472 "EHLO fmmailgate07.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752645Ab1KUVkg convert rfc822-to-8bit (ORCPT ); Mon, 21 Nov 2011 16:40:36 -0500 Date: Mon, 21 Nov 2011 22:40:34 +0100 (CET) From: "Nicolas Kalkhof" To: maciej.rutecki@gmail.com Cc: "linux-kernel@vger.kernel.org" Message-ID: <615350841.1406384.1321911635013.JavaMail.fmail@mwmweb021> Subject: Re: [REGRESSION] sudden cpu hogging in kernel 3.2 rc-series MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Priority: 3 Importance: normal Sensitivity: Normal X-Provags-ID: V01U2FsdGVkX1/eT2i3B54JlSBqDmTfk0u4CkV2lbnJIi7V5BUzgWtxIKoSCLfL0gnG BYCB8mfP63RXX8Ew3xkAtw== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This happens on my machine after some minutes, too when running X and the trinity desktop. the cpu continuously uses up additional ~10 watts comparing to older 3.1 kernels. The issue remains high even after I kill X. A closer investigation shows that poll_idle uses up the cpu (see dump below). Is it normal for poll_idle to use up all ressources? CPU: Intel Sandy Bridge microarchitecture, speed 2.701e+06 MHz (estimated) Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (No unit mask) count 100000 samples  %        app name                 symbol name 524625   96.8279  vmlinux                  poll_idle 7807      1.4409  cfbimgblt                /cfbimgblt 813       0.1501  vmlinux                  rb_get_reader_page 806       0.1488  vmlinux                  fbcon_redraw.clone.30 616       0.1137  vmlinux                  i8042_interrupt 454       0.0838  vmlinux                  bit_putcs 414       0.0764  vmlinux                  ring_buffer_consume 373       0.0688  vmlinux                  _cond_resched 301       0.0556  cfbcopyarea              /cfbcopyarea 277       0.0511  libstdc++.so.6.0.14      /usr/lib64/gcc/x86_64-pc-linux-gnu/4.5.3/libstdc++.so.6.0.14 239       0.0441  cfbfillrect              /cfbfillrect .... Regards Nic -----Ursprüngliche Nachricht----- Von: "Maciej Rutecki" Gesendet: Nov 21, 2011 10:11:17 PM An: "Nicolas Kalkhof" Betreff: Re: [REGRESSION] sudden cpu hogging in kernel 3.2 rc-series >On piątek, 18 listopada 2011 o 21:33:15 Nicolas Kalkhof wrote: >> Hello, >> >> since the merges for kernel 3.2 came in late october, my mobile i7 2620M >> sandybridge cpu/gpu seems to run hotter (approx 10 °C) when idling and >> after some minutes according to top the cpu load goes up on all cores but >> the cpu frequency stays low (800 MHz) as well as the gpu (650MHz) and the >> system is responding well. Yet still additional 5-8 watts are continously >> drained from the power supply. Something is throttling up :(. Oprofile >> shows that the kernel hogs the cpu (see dump below). This happens with >> every kernel since the 3.2 merge window closed up to latest linux-next. I >> wasn't able to track the bad commit down yet. >> >> Could someone please confirm the issue? >> > >I observed similar behaviour, few minutes after boot, when KDE is working >plasma-desktop process (sometimes another) uses 20-50% cpu. System and kernel >works without any kernel, but cpu usage is greater than in 3.1 (and older). > >Hardware: old hp/compaq nx6310 > >Add this mail to regression list. > >Regards >-- >Maciej Rutecki >http://www.mrutecki.pl ___________________________________________________________ SMS schreiben mit WEB.DE FreeMail - einfach, schnell und kostenguenstig. Jetzt gleich testen! http://f.web.de/?mc=021192