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Date:      Mon, 29 Nov 2004 23:30:41 -0600
From:      Dan Nelson <dnelson@allantgroup.com>
To:        Julian Elischer <julian@elischer.org>
Cc:        Sean Welch <Sean_Welch@alum.wofford.org>
Subject:   Re: top under 5.3-RELEASE
Message-ID:  <20041130053040.GL5518@dan.emsphone.com>
In-Reply-To: <41AB9151.8070601@elischer.org>
References:  <20041128233704.GB62951@NitroPhys.welchsmnet.net> <20041129154805.GD5518@dan.emsphone.com> <41AB8174.4090205@elischer.org> <20041129205408.GH5518@dan.emsphone.com> <41AB9151.8070601@elischer.org>

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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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