Re: Kernel profiles anyone?

From: Lee Revell (rlrevell_at_joe-job.com)
Date: 09/07/05

  • Next message: Maurice Volaski: "Re: Kernel 2.6.13 is hiding devices from /dev [Was Why is the kernel hiding drbd devices?}" 
    To: John Richard Moser <nigelenki@comcast.net>
Date:	Wed, 07 Sep 2005 00:26:55 -0400

    On Tue, 2005-09-06 at 21:35 -0400, John Richard Moser wrote:
    > -----BEGIN PGP SIGNED MESSAGE-----
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    >
    > Are there any recent kernel profiles? I think from an acedemic
    > perspective it'd be nice to see some graphs and numbers nobody
    > understands showing where the longest running code paths in the kernel
    > occur. It might also be nice for those latency whores (*runs to the
    > back and raises hand*) and those who want to increase overall
    > performance and efficiency; then there'd be a map showing . . .
    > something that only kernel hackers could possibly understand or care about.

    There's a latency histogram option in the -rt patch set. You can pipe
    the output through gnuplot and get some cool graphs. Then you can
    use /proc/latency_trace to try and guess what code paths the peaks on
    the graphs correspond to. The timer interrupt will be the biggest peak,
    around 23 usecs last time I checked.

    I haven't done it lately so it would be interesting to see the current
    graphs. Someone could make a really good presentation out of it at some
    kernel development conference.

    Lee

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  • Next message: Maurice Volaski: "Re: Kernel 2.6.13 is hiding devices from /dev [Was Why is the kernel hiding drbd devices?}"

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