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From: Daniel Phillips <phillips@bonn-fries.net>
To: "Albert D. Cahalan" <acahalan@cs.uml.edu>
Subject: Re: PROPOSAL: dot-proc interface [was: /proc stuff]
Date: Tue, 6 Nov 2001 01:54:10 +0100
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On November 5, 2001 11:46 pm, Albert D. Cahalan wrote:
> Daniel Phillips writes:
> 
> > I've done quite a bit more kernel profiling and I've found that
> > overhead for converting numbers to ascii for transport to proc is
> > significant, and there are other overheads as well, such as the
> > sprintf and proc file open.  These must be matched by corresponding
> > overhead on the user space side, which I have not profiled.  I'll
> > take some time and present these numbers properly at some point.
> 
> You said "top -d .1" was 18%, with 11% user, and konsole at 9%.
> So that gives:
> 
> 9% konsole
> 7% kernel
> 2% top
> 0% X server ????

No, the konsole 9% is outside of top's 18%.

> If konsole is well-written, that 9% should drop greatly as konsole
> falls behind on a busy system. For example, when scrolling rapidly
> it might skip whole screenfuls of data. Hopefully those characters
> are rendered in a reasonably efficient way.

I don't think I'll try to optimize konsole/QT/X today, thanks ;-)

Lets just not lose sight of the overhead connected with ASCII proc IO, it's a 
lot more than some seem to think.

--
Daniel
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