Re: 2.6.0-test2-mm3 osdl-aim-7 regression

From: Cliff White
Date: Fri Aug 08 2003 - 16:02:57 EST


> On Thu, 7 Aug 2003 05:10, Cliff White wrote:
> > > Binary searching (insert gratuitous rant about benchmarks that take more
> > > than two minutes to complete) reveals that the slowdown is due to
> > > sched-2.6.0-test2-mm2-A3.
>
> This is most likely the round robinning of tasks every 25ms. The extra
> overhead of nanosecond timing I doubt could make that size difference (but I
> could be wrong). There is some tweaking of this round robinning in my code
> which may help this, but it won't bring it back up to original performance I
> believe. Two things to try are add my patches up to O12.3int first to see how
> much (if at all!) it helps, and change TIMESLICE_GRANULARITY in sched.c to
> (MAX_TIMESLICE) which basically disables it completely. If there is still a
> drop in performance with this, the remainder is the extra locking/overhead in
> nanosecond timing.
>
> Con
>
Added your patches to PLM, from your web site. We've had other issues slowing
up the
4-cpu queue, but the two CPU tests ran. On these smaller platforms, not seeing
big
difference between the patches.

STP id PLM# Kernel Name Workfile MaxJPM MaxUser Host %Change
277231 2042 CK-O13-O13.1int-1 new_dbase 1333.60 22 stp2-002 0.00
277230 2041 CK-O12.3-O13int-1 new_dbase 1344.23 24 stp2-003 0.80
277228 2040 CK-012.2-O12.3int-1 new_dbase 1328.86 22 stp2-002 -0.36
All are a bit better than stock:
276572 2020 linux-2.6.0-test2 new_dbase 1320.68 22 stp2-000 -0.96
----
Code location:
bk://developer.osdl.org/osdl-aim-7
More results:
http://developer.osdl.org/cliffw/reaim/index.html

Run parameters:

./reaim -s2 -x -t -i2 -f workfile.new_dbase -r3 -b -l./stp.config

cliffw


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