Messages in this thread | | | Date | Mon, 21 Nov 2011 22:40:34 +0100 (CET) | From | "Nicolas Kalkhof" <> | Subject | Re: [REGRESSION] sudden cpu hogging in kernel 3.2 rc-series |
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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" <maciej.rutecki@gmail.com> Gesendet: Nov 21, 2011 10:11:17 PM An: "Nicolas Kalkhof" <nkalkhof@web.de> 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
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