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Date: Fri, 18 Feb 2011 10:12:56 -0700
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From: andrey mirtchovski <mirtchovski@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
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Subject: Re: [9fans] Modern development language for Plan 9,
 WAS: Re: RESOLVED: recoving important header file rudely
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> The kernel has a timer that
> updates this page atomically.

which timer updates the page even when nobody is interested in knowing
what the time is, increasing the noise in the system[1]. i still keep
graphs of a full-blown plan9 cpu server with users logged in and close
to 200 running processes exhibiting very little deviation:

http://mirtchovski.com/screenshots/ftq.jpg

people are doing work negating the timer "optimization":
http://ozlabs.org/~anton/linux/osjitter/

andrey

[1] http://www.computer.org/portal/web/csdl/doi/10.1109/CLUSTR.2004.1392636