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* Regression with idle cpu cycle handling in 2.6.24 (compared to 2.6.22)
@ 2008-01-19 14:05 dAniel hAhler
  2008-01-19 14:52 ` dAniel hAhler
  0 siblings, 1 reply; 6+ messages in thread
From: dAniel hAhler @ 2008-01-19 14:05 UTC (permalink / raw)
  To: LKML


I have BOINC running in the background with niceness 19.
With a 2.6.22 kernel, only idle cpu cycles get assigned to this process, as

But with the 2.6.24 kernel, the BOINC process gets at least about half of
all CPU cycles, even if there's another process (owned by another user)
requesting CPU cycles (e.g. "cat /dev/urandom > /dev/null")

This happens with the Ubuntu kernel (from Hardy) and the daily builds from (where I've just tested
rc8 now).

It appears that every user (here "boinc" and my user) get the same portion
of the overall CPU cycles, regardless of the process niceness.

Is this expected behaviour?

I'm using an AMD64 3000+ processor. Please ask for additional information, if
you need it (e.g. kernel config).

$ cat /dev/urandom > /dev/null &
$ sudo -u another_user nice -n 19 python -c 'i = 0;
while 1:
  i += i

The niced process should get nearly no CPU cycles.

The niced process gets about half of the CPU cycles (according to "top").

The bug has been reported for Ubuntu on


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2008-01-22  1:59 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2008-01-19 14:05 Regression with idle cpu cycle handling in 2.6.24 (compared to 2.6.22) dAniel hAhler
2008-01-19 14:52 ` dAniel hAhler
2008-01-20  3:33   ` Dhaval Giani
2008-01-20  4:03     ` Dhaval Giani
2008-01-21 17:18     ` Srivatsa Vaddagiri
2008-01-22  1:59       ` dAniel hAhler

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