Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!mcsun!ukc!warwick!cudep
From: cudep@warwick.ac.uk (Ian Dickinson)
Newsgroups: comp.sys.sequent
Subject: Re: timing parallel programs
Keywords: timing, sequent, multi-processor
Message-ID: <398@clover.warwick.ac.uk>
Date: 12 Feb 90 10:28:17 GMT
References: <1324@csisles.Bristol.AC.UK>
Reply-To: cudep@warwick.ac.uk (Ian Dickinson)
Organization: Team Limpid's Death Mollusc From Hell Tour - Europe 1992
Lines: 20

In article <1324@csisles.Bristol.AC.UK> beaumont@CompSci.Bristol.AC.UK (Tony Beaumont) writes:
>Is there a way to get a processor to exclusively run a process?

Yes.
If you are running the code as setuid.
There is a system call called tmp_affinity or similar
(try 'man -k affinity' and you should get something in section 2)
This call will make a process have exclusive use of a single processor.
If you make all the parallel processes call this,
then spin until they are synchronised,
you should be able to conduct reasonable tests
without an other process intervening.

It might still be worthwhile running the tests during light load periods
so bus congestion, paging etc are less of a problem.

Hokay!
-- 
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