Re: fair group scheduler not so fair?

From: Srivatsa Vaddagiri
Date: Tue May 27 2008 - 13:19:34 EST


On Wed, May 21, 2008 at 05:59:22PM -0600, Chris Friesen wrote:
> I then redid the test with two hogs in one group and three hogs in the
> other group. Unfortunately, the cpu shares were not equally distributed
> within each group. Using a 10-sec interval in "top", I got the following:

I ran with this combination (2 in Group a and 3 in Group b) on top of the
experimental patch I sent and here's what I get:

4350 root 20 0 1384 228 176 R 53.8 0.0 52:27.54 1 hoga
4542 root 20 0 1384 228 176 R 49.3 0.0 3:39.76 0 hoga
4352 root 20 0 1384 232 176 R 36.0 0.0 26:53.50 1 hogb
4351 root 20 0 1384 228 176 R 32.0 0.0 26:47.54 0 hogb
4543 root 20 0 1384 232 176 R 29.0 0.0 2:03.62 0 hogb

Note that fairness (using load balance approach we have currently) works
over a long window. Usually I observe with "top -d30". Higher the
asymmetry of task-load distribution, longer it takes to converge to
fairness.

--
Regards,
vatsa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/