RE: [2.6.25-stable PATCH] regression: powertop says 120K wakeups/sec

From: Pallipadi, Venkatesh
Date: Mon Apr 28 2008 - 17:10:51 EST




>-----Original Message-----
>From: Daniel Klaffenbach [mailto:danielklaffenbach@xxxxxxxxx]
>Sent: Monday, April 28, 2008 11:01 AM
>To: Pallipadi, Venkatesh
>Cc: Len Brown; Linux Kernel Mailing List
>Subject: Re: [2.6.25-stable PATCH] regression: powertop says
>120K wakeups/sec
>
>Pallipadi, Venkatesh wrote:
>> Did C1, C2 work fine with 2.6.24?
>> Can you send me the full dmesg when it is failing to enter
>C1, C2 with
>> latest git + patch.
>> Output of
>> #grep . /sys/devices/system/cpu/cpu*/cpuidle/*/*
>> And also attach the acpidump output (pmtools package here
>> http://www.lesswatts.org/projects/acpi/utilities.php)
>No, C1/C2 did not seem to work with 2.6.24 - at least powertop
>reported 99,9%
>C0 usage. It was the same behavior as after applying the wakeup patch.
>However in 2.6.25 and 2.6.25-git11 C1/C2 worked correctly and
>C2 showed up in
>pt. But after applying your patch to 2.6.25-git11 they did not:
>
>git11:
>PowerTOP version 1.9 (C) 2007 Intel Corporation
>Cn Avg residency P-states (frequencies)
>C0 (cpu running) ( 9,4%) 1,80 Ghz 100,0%
>C1 0,0ms ( 0,0%) 1,60 Ghz 0,0%
>C2 0,4ms (90,6%) 800 Mhz 0,0%
>Wakeups-from-idle per second : 9051,0 interval: 5,0s
>
>git11 with wakeup-patch:
>PowerTOP version 1.9 (C) 2007 Intel Corporation
>Cn Avg residency P-states (frequencies)
>C0 (cpu running) (99,9%) 1,80 Ghz 100,0%
>C1 0,0ms ( 0,0%) 1,60 Ghz 0,0%
>C2 0,2ms ( 0,1%) 800 Mhz 0,0%
>Wakeups-from-idle per second : 59,8 interval: 10,0s
>
>In both cases the system was idle. I've uploaded the files you wanted:
>http://www-user.tu-chemnitz.de/~klada/misc/kernel/cpuidle_git11.txt
>http://www-user.tu-chemnitz.de/~klada/misc/kernel/cpuidle_git11
>_wakeuppatch.txt
>http://www-user.tu-chemnitz.de/~klada/misc/kernel/dmesg_git11.txt
>http://www-user.tu-chemnitz.de/~klada/misc/kernel/dmesg_git11_w
akeuppatch.txt
>http://www-user.tu-chemnitz.de/~klada/misc/kernel/nx6125_acpidump.out
>
>If there is anything else I can do for debugging this issue
>please let me
>know.
>

With git11+wakeup patch, things seems to be working fine as per
>http://www-user.tu-chemnitz.de/~klada/misc/kernel/cpuidle_git11_wakeupp
atch.txt

CPU is spending most of the time in C3 state. Looks like there is some
problem with
powertop reporting here. I know there were some changes to this area in
powertop.
Can you try the latest powertop version from svn
(http://www.lesswatts.org/projects/powertop/download.php) and see
whether the issue is fixed.

Thanks,
Venki
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