Re: 16-way stacker performance

From: serue@private
Date: Thu Jun 02 2005 - 15:20:29 PDT


Quoting Valdis.Kletnieks@private (Valdis.Kletnieks@private):
> On Thu, 02 Jun 2005 13:37:15 CDT, serue@private said:
> 
> > Num     Parent   Child   Child  Jobs per   Jobs/min/  Std_dev  Std_dev  JTI
> > Forked  Time     SysTime UTime   Minute     Child      Time     Percent 
> > 1       0.07     0.03    0.03    87428.57   87428.57   0.00     0.00     100 
> > 3       0.12     0.17    0.18    153000.00  51000.00   0.00     0.00     100
> 
> OK.. Found it.  The granularity on the stime and utime is basically __hz - so
> on a kernel that uses CONFIG_HZ=100, we only have 1 or 2 digits of precision here.
> Even with CONFIG_HZ=1000, we barely get 3 digits.
> 
> Is there any way to get REAIM to loop around several hundred times, so the
> times are into the 1-10 second range rather than hundredths of a second? If we
> get the CPU time up to the 5-10 second range, we'll get 3 digits even at HZ=100....

Should be doable, and I can make that change in the local copy of the
reaim sources, but I won't have a chance to look into it until next week
at the earliest.

> (What does "zcat /proc/config.gz | grep -i hz" give on the test boxes, anyhow?)

Nothing...

-serge



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