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

[Cliff White <cliffw@osdl.org>]

> 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