RE: [patch] sched: auto-tuning task-migration

["Chen, Kenneth W" <kenneth.w.chen@intel.com>]

Ingo Molnar wrote on Wednesday, October 06, 2004 6:30 AM
> the following patch adds a new feature to the scheduler: during bootup
> it measures migration costs and sets up cache_hot value accordingly.
>
> could you try this patch on your testbox and send me the bootlog? How
> close does this method get us to the 10 msec value you measured to be
> close to the best value? The patch is against 2.6.9-rc3 + the last
> cache_hot fixpatch you tried.

Ran it on a similar system.  Below is the output.  Haven't tried to get a
real benchmark run with 42 ms cache_hot_time.  I don't think it will get
peak throughput as we already start tapering off at 12.5 ms.

task migration cache decay timeout: 10 msecs.
CPU 1: base freq=199.458MHz, ITC ratio=15/2, ITC freq=1495.941MHz+/--1ppm
CPU 2: base freq=199.458MHz, ITC ratio=15/2, ITC freq=1495.941MHz+/--1ppm
CPU 3: base freq=199.458MHz, ITC ratio=15/2, ITC freq=1495.941MHz+/--1ppm
Calibrating delay loop... 2232.84 BogoMIPS (lpj=1089536)
Brought up 4 CPUs
Total of 4 processors activated (8939.60 BogoMIPS).
arch cache_decay_nsec: 10000000
migration cost matrix (cache_size: 9437184, cpu: 1500 MHz):
        [00]  [01]  [02]  [03]
[00]:   50.2  42.8  42.9  42.8
[01]:   42.9  50.2  42.1  42.9
[02]:   42.9  42.9  50.2  42.8
[03]:   42.9  42.9  42.9  50.2
min_delta: 44785782
using cache_decay nsec: 44785782 (42 msec)