Re: fair group scheduler not so fair?

[Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>]

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