Re: Benchmarking objrmap under memory pressure

From: Bill Davidsen
Date: Wed Apr 14 2004 - 13:12:41 EST


Andrew Morton wrote:
"Martin J. Bligh" <mbligh@xxxxxxxxxxx> wrote:

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 ;)

I was looking at the pagefault counts, myself. I'd like to see disk io counts for each run, that sometimes brings enlightenment. Maybe do 20 sec counts with diorate or some such.
(http://pages.prodigy.net/davidsen/ if you don't have your own favorite tool)

Average of five runs, please...

--
-bill davidsen (davidsen@xxxxxxx)
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me
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