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To: Stephen Roome <steve@visint.co.uk>
cc: Terry Lambert <terry@lambert.org>, freebsd-smp@FreeBSD.ORG
Subject: Re: Where to start SMP? 
In-reply-to: Your message of "Wed, 07 May 1997 14:37:01 BST."
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Date: Wed, 07 May 1997 08:28:02 -0700
From: Peter Grehan <grehan@Ipsilon.COM>
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>>This would let a single SMP kernel work on all
>> hardware, regardless of which options must be twiddled to get it to
>> go.  The alternative is multiple "SMP GENERIC" configurations -- not
>> a likely event.
>
>Maybe, but surely some of the changes to run an efficient SMP system 
>should come at kernel compile level. Unless FreeBSD moves to a modular 
>system on the scale of something like HURD this looks likely to decrease 
>performance.

 Have a look at http://www.digital.com/info/DTJF03/DTJF03SC.TXT -
a single kernel is used, with the lock strategy determined at
boot-time. The overhead for this was brought down to just 3% over
that of a system that had locks compiled out.

 So it is possible, but may require some effort.

later,

Peter.