Messages in this thread | | | Date | Wed, 16 Jan 2008 17:19:51 +0100 | From | Ingo Molnar <> | Subject | Re: Performance loss 2.6.22->22.6.23->2.6.24-rc7 on CPU intensive benchmark on 8 Core Xeon |
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* Colin Fowler <elethiomel@gmail.com> wrote:
> Hi Ingo, I'll need to convince my supervisor first if I can release a > binary. Technically anythin glike this needs to go through our > University's "innovations department" and requires lengthy paperwork > and NDAs :(.
a binary wouldnt work for me anyway. But you could try to write a "workload simulator": just pick out the pthread ops and replace the worker functions with some dummy stuff that just touches an array that has similar size to the tiles (in a tight loop). Make sure it has similar context-switch rate and idle percentage as your real workload - then send us the .c file. As long as it's a single .c file that runs for a few seconds and outputs a precise enough "run time" result, kernel developers would pick it up and use it for optimizations. To get the # of cpus automatically you can do:
cpus = system("exit `grep processor /proc/cpuinfo | wc -l`"); cpus = WEXITSTATUS(cpus);
and start as many threads as many CPUs there are in the system.
Ingo
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