Fedora 14 under constant load

[Orion Poplawski]

On 10/14/2010 05:58 PM, Jesse Keating wrote:
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> On 10/14/2010 04:49 PM, John Poelstra wrote:
>> That's what's so mysterious, very little CPU time or activity.
>
> I saw this at one point, and the kernel folks found it to be a load
> balancing thing gone awry in the kernel.
>
> 2.6.35.6-33.rc1 seems to include a patch:
>
> - - Add sched-35-increment-cache_nice_tries-only-on-periodic-lb.patch,
> another fix for excessive scheduler load balancing.
>
> That should be in kernel-2.6.35.6-39.fc14, which is in dist-f14.  My
> load went down and the laptop (also an M1330) has cooled down a bit, but
> it is still above one usually.

With 2.6.35.6-43.fc14.i686.PAE, after letting the machine quiet down a bit 
after logging in and starting up Firefox and Thunderbird:


top - 10:45:59 up 8 min, 14 users,  load average: 0.81, 1.65, 1.12
Tasks: 184 total,   2 running, 182 sleeping,   0 stopped,   0 zombie
Cpu(s):  2.0%us,  0.8%sy,  0.0%ni, 97.0%id,  0.2%wa,  0.0%hi,  0.0%si,  0.0%st

Top causes for wakeups:
   40.6% (117.7)   [kernel scheduler] Load balancing tick
   29.8% ( 86.4)   firefox
    5.9% ( 17.1)   konsole
    5.4% ( 15.6)   PS/2 keyboard/mouse/touchpad interrupt
    3.7% ( 10.7)   thunderbird-bin
    3.6% ( 10.5)   [ata_piix] <interrupt>

Actually moving the mouse and typing seems to bring the load back up to 1. 
Never saw it go below .8

-- 
Orion Poplawski
Technical Manager                     303-415-9701 x222
NWRA/CoRA Division                    FAX: 303-415-9702
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