Messages in this thread | ![/](/images/icornerl.gif) | | Date | Sun, 1 Feb 2009 13:19:10 +0200 | Subject | Re: [PATCH 2.6.28 1/2] memory: improve find_vma | From | Daniel Lowengrub <> |
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On 1/29/09, Ingo Molnar <mingo@elte.hu> wrote: > Here's an mmap performance tester: > > http://redhat.com/~mingo/misc/mmap-perf.c > > maybe that shows a systematic effect. If you've got a Core2 based > test-system then you could try perfstat as well, for much more precise > instruction counts. (can give you more info about how to do that if you > have such a test-system.) > > Ingo > I compiled mmap-perf.c an ran it with ./mmap-perf 1 (not as root, does that matter?). As obvious from the code, the output that I got was the final state of the /proc/[self]/maps file. How does this information tell me about performance? Anyhow, here're the first 10 lines of the [heap] part of the output using the standard kernel: 0965b000-0967c000 rw-p 0965b000 00:00 0 [heap] 86007000-86009000 rw-p 86007000 00:00 0 86009000-8600a000 ---p 86009000 00:00 0 86018000-8601b000 rw-p 86018000 00:00 0 8601c000-86023000 -w-p 8601c000 00:00 0 86023000-86026000 rw-p 86023000 00:00 0 86026000-86029000 r--p 86026000 00:00 0 8603e000-86040000 rw-p 8603e000 00:00 0 86048000-8604c000 r--p 86048000 00:00 0 8604f000-86054000 ---p 8604f000 00:00 0 and here're the first 10 lines of the output with the patch applied: 09596000-095b7000 rw-p 09596000 00:00 0 [heap] 860ab000-860ad000 rw-p 860ab000 00:00 0 860ad000-860ae000 ---p 860ad000 00:00 0 860bc000-860bf000 rw-p 860bc000 00:00 0 860c0000-860c7000 -w-p 860c0000 00:00 0 860c7000-860ca000 rw-p 860c7000 00:00 0 860ca000-860cd000 r--p 860ca000 00:00 0 860e2000-860e4000 rw-p 860e2000 00:00 0 860ec000-860f0000 r--p 860ec000 00:00 0 860f3000-860f8000 ---p 860f3000 00:00 0 I can't see how this can show performance differences but I'm not sure what other part of the output is relevant. Should I run it with some other options? Thanks, Daniel
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