Messages in this thread | | | Date | Thu, 30 Apr 2009 09:20:58 -0400 | From | "Alan D. Brunelle" <> | Subject | Re: [PATCH 0/9] cgroup: io-throttle controller (v13) |
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Hi Andrea -
FYI: I ran a simple test using this code to try and gauge the overhead incurred by enabling this technology. Using a single 400GB volume split into two 200GB partitions I ran two processes in parallel performing a mkfs (ext2) on each partition. First w/out cgroup io-throttle and then with it enabled (with each task having throttling enabled to 400MB/second (much, much more than the device is actually capable of doing)). The idea here is to see the base overhead of just having the io-throttle code in the paths.
Doing 30 runs of each (w/out & w/ io-throttle enabled) shows very little difference (time in seconds)
w/out: min=80.196 avg=80.585 max=81.030 sdev=0.215 spread=0.834 with: min=80.402 avg=80.836 max=81.623 sdev=0.327 spread=1.221
So only around 0.3% overhead - and that may not be conclusive with the standard deviations seen.
--
FYI: The test was run on 2.6.30-rc1+your patches on a 16-way x86_64 box (128GB RAM) plus a single FC volume off of a 1Gb FC RAID controller.
Regards, Alan D. Brunelle Hewlett-Packard
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