Messages in this thread | | | Date | Fri, 16 Nov 2007 10:35:25 -0800 | From | "Ray Lee" <> | Subject | Re: [patch] Give kjournald a IOPRIO_CLASS_RT io priority |
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On Nov 16, 2007 8:25 AM, Alan D. Brunelle <alan.brunelle@hp.com> wrote: > 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.
Out of curiosity, what are the mount options for the freshly created ext3 fs? In particular, are you using noatime, nodiratime?
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