Re: Benchmarking objrmap under memory pressure

Martin J. Bligh
2004-04-14T00:26:42Z

>> UP Athlon 2100+ with 512Mb of RAM. Rebooted clean before each test
>> then did "make clean; make vmlinux; make clean". Then I timed a
>> "make -j 256 vmlinux" to get some testing under mem pressure.
>>
>> I was trying to test the overhead of objrmap under memory pressure,
>> but it seems it's actually distinctly negative overhead - rather pleasing
>> really ;-)
>>
>> 2.6.5
>> 225.18user 30.05system 6:33.72elapsed 64%CPU (0avgtext+0avgdata 0maxresident)k
>> 0inputs+0outputs (37590major+2604444minor)pagefaults 0swaps
>>
>> 2.6.5-anon_mm
>> 224.53user 26.00system 5:29.08elapsed 76%CPU (0avgtext+0avgdata 0maxresident)k
>> 0inputs+0outputs (29127major+2577211minor)pagefaults 0swaps
>
> A four second reduction in system time caused a one minute reduction in
> runtime? Pull the other one ;)
>
> Average of five runs, please...

You're right - it's rather variable. Still doesn't look bad though.

2.6.5
Average elapsed = 6:11
224.92user 30.15system 5:44.19elapsed 74%CPU (0avgtext+0avgdata 0maxresident)k
225.04user 30.23system 6:02.49elapsed 70%CPU (0avgtext+0avgdata 0maxresident)k
225.28user 29.60system 5:48.22elapsed 73%CPU (0avgtext+0avgdata 0maxresident)k
225.81user 31.75system 6:42.38elapsed 64%CPU (0avgtext+0avgdata 0maxresident)k
225.23user 30.20system 6:40.48elapsed 63%CPU (0avgtext+0avgdata 0maxresident)k

2.6.5-anon_mm
Average elapsed = 5:43
224.34user 25.43system 4:51.23elapsed 85%CPU (0avgtext+0avgdata 0maxresident)k
224.23user 25.93system 5:00.79elapsed 83%CPU (0avgtext+0avgdata 0maxresident)k
224.39user 26.36system 5:37.71elapsed 74%CPU (0avgtext+0avgdata 0maxresident)k
225.65user 27.13system 6:28.00elapsed 65%CPU (0avgtext+0avgdata 0maxresident)k
225.14user 27.26system 6:39.61elapsed 63%CPU (0avgtext+0avgdata 0maxresident)k

I've kicked off the -aa tree tests - will post them later tonight.