Here are the results for the latest tests, some notes:
o The machine actually has 8GiB of RAM, so the tests still may end up
using (some) page cache. (But at least it was the same for both kernels!
:-) )
o Sorry the results took so long - the updated tree size caused the
runs to take > 12 hours...
o The longer runs seemed to bring down the standard deviation a bit,
although they are still quite large.
o 10 runs per test (read large file, read a tree, overwrite large
file), with averages presented.
o 1st 4 columns (min, avg, max, std dev) refer to the average run
lengths for the tests - real time, in seconds
o The last 3 columns are extracted from iostat results over the course
of the whole run.
o The read a tree test certainly stands out - the other 2 large file
manipulations have the two kernels within a couple of percent, but the
read a tree test has Arjan's patch taking about 47%(!) longer on
average. The increased %iowait & %system time in all 3 cases is interesting.
Read large file:
Kernel Min Avg Max Std Dev %user %system %iowait
--------------------------------------------------------------
base : 201.6 215.1 275.5 22.8 0.26% 4.69% 33.54%
arjan: 198.0 210.3 261.5 18.5 0.33% 10.24% 54.00%
Read a tree:
Kernel Min Avg Max Std Dev %user %system %iowait
--------------------------------------------------------------
base : 3518.2 4631.3 5991.3 784.6 0.19% 3.29% 23.56%
arjan: 5731.6 6849.8 7777.4 731.6 0.32% 9.90% 52.70%
Overwrite large file:
Kernel Min Avg Max Std Dev %user %system %iowait
--------------------------------------------------------------
base : 104.2 147.7 239.5 38.4 0.02% 0.05% 1.08%
arjan: 106.2 149.7 239.2 38.4 0.25% 0.79% 14.97%
Let me know if there is anything else I can do to elaborate, or if you
have suggestions for further testing.
Alan
-
