lkml.org 
[lkml]   [2010]   [Feb]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC GIT PULL] perf/trace/lock optimization/scalability improvements
    On Wed, Feb 03 2010, Frederic Weisbecker wrote:
    > Hi,
    >
    > There are many things that happen in this patchset, treating
    > different problems:
    >
    > - remove most of the string copy overhead in fast path
    > - open the way for lock class oriented profiling (as
    > opposite to lock instance profiling. Both can be useful
    > in different ways).
    > - remove the buffers muliplexing (less contention)
    > - event injection support
    > - remove violent lock events recursion (only 2 among 3, the remaining
    > one is detailed below).
    >
    > Some differences, by running:
    > perf lock record perf sched pipe -l 100000
    >
    > Before the patchset:
    >
    > Total time: 91.015 [sec]
    >
    > 910.157300 usecs/op
    > 1098 ops/sec
    >
    > After this patchset applied:
    >
    > Total time: 43.706 [sec]
    >
    > 437.062080 usecs/op
    > 2288 ops/sec

    This does a lot better here, even if it isn't exactly stellar
    performance. It generates a LOT of data:

    root@nehalem:/dev/shm # time perf lock rec -fg ls
    perf.data perf.data.old
    [ perf record: Woken up 0 times to write data ]
    [ perf record: Captured and wrote 137.224 MB perf.data (~5995421
    samples) ]

    real 0m3.320s
    user 0m0.000s
    sys 0m3.220s

    Without -g, it has 1.688s real and 1.590s sys time.

    So while this is orders of magnitude better than the previous patchset,
    it's still not anywhere near lean. But I expect you know that, just
    consider this a 'I tested it and this is what happened' report :-)

    --
    Jens Axboe



    \
     
     \ /
      Last update: 2010-02-03 11:29    [W:0.021 / U:32.084 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site