Re: top under 5.3-RELEASE

From: Dan Nelson (dnelson_at_allantgroup.com)
Date: 11/30/04

  • Next message: Jeff Roberson: "Re: Giantless VFS." 
    Date: Mon, 29 Nov 2004 23:30:41 -0600
To: Julian Elischer <julian@elischer.org>

    In the last episode (Nov 29), Julian Elischer said:
    > understood.. but when 'ps' gets the information, it gets each
    > thread.. where does the info get stored? the threads may have just
    > flashed into existence a fraction of a second ago, and prior to that
    > thay may have belonged to a compeltely different process. It's not a
    > simple problem. However there may be some relatively "ok" answers if
    > we can define well enough what we want to see. For example all
    > taking the total cputime for the KSEGRP and dividing it by the number
    > of non-sleeping threads might be a possibility. (or some variant of
    > that).

    Is the real problem that %CPU and WCPU are no longer used by the
    schedulers in any meaningful way? I thought at one point they were
    used to dampen the priority of cpu-intensive proceses. Maybe they
    should be removed and replaced with some other counters that can record
    cpu usage better. %CPU can certainly be extracted by subtracting the
    "struct rusage" values every sampling interval; unixtop does that for
    quite a few OSes where %CPU isn't available or is useless. WCPU is
    nice to get a longer-term picture of what processes are consistently
    using CPU though. I suppose top could maintain its own running average
    by averaging its calculated %CPU over an interval, but ps couldn't. 

    -- 
	Dan Nelson
	dnelson@allantgroup.com
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  • Next message: Jeff Roberson: "Re: Giantless VFS."

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