Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 09 May 1997 17:25:00 -0600
From:      Steve Passe <smp@csn.net>
To:        James Mansion <james@westongold.com>
Cc:        smp@FreeBSD.ORG
Subject:   Re: maptable of SuperMicro P6DNH 
Message-ID:  <199705092325.RAA15100@Ilsa.StevesCafe.com>
In-Reply-To: Your message of "Tue, 06 May 1997 18:41:20 BST." <336F6D40.547D@westongold.com> 

next in thread | previous in thread | raw e-mail | index | archive | help
Hi,

> Given that the 'cost' of having SMP code in place should be low (and
> could be optimised further for the special case where the number of
> active CPUs is 1) is there a reason not to complete the integration to
> the point where there is no ifdef difference between SMP and UP source
> code?

I don't see it happening.  There are major differences in the hardware on
an SMP motherboard and a UP motherboard.  The software differences are much 
more than just locking.  A completely different INTerrupt sub-system is in 
order.  Different scheduling strategies will be in place.  The list goes on...
Even if you could engineer it so that there was less than 5% cost at runtime, 
why should a UP user have to pay that cost.

--
Steve Passe	| powered by 
smp@csn.net	|            Symmetric MultiProcessor FreeBSD





Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199705092325.RAA15100>