Date: Fri, 15 Mar 2002 10:08:53 +0000 From: Josh Paetzel <friar_josh@webwarrior.net> To: Terry Lambert <tlambert2@mindspring.com> Cc: Matthew Emmerton <matt@gsicomp.on.ca>, hackers@FreeBSD.ORG Subject: Re: Interesting sysctl variables in Mac OS X with hw info Message-ID: <20020315100853.P287@twincat.vladsempire.net> In-Reply-To: <3C902B36.4D4EB8E@mindspring.com>; from tlambert2@mindspring.com on Wed, Mar 13, 2002 at 08:46:46PM -0800 References: <Pine.BSF.4.21.0203131636280.70491-100000@InterJet.elischer.org> <006601c1cb06$b9f07370$1200a8c0@gsicomp.on.ca> <3C902B36.4D4EB8E@mindspring.com>
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On Wed, Mar 13, 2002 at 08:46:46PM -0800, Terry Lambert wrote: > Matthew Emmerton wrote: > > > > > This was actually discussed a while back (a month or two ago). > > > > > > > > > > It got really bogged down when someone pointed out that > > > > > they were running CPUs with different clock rates in their > > > > > SMP box, just to see what the net effect would be. THe > > > > > problem was, of course, which one do you report, when the > > > > > numbers don't match exactly, and/or how do you report both > > > > > (or N)? > > > > I thought it was a real bad thing to run CPUs in SMP systems at different > > clock rates. In fact, I never thought it was possible. I know I can't on > > my old 2-way P166 box, but things have changed a lot since '91. > > It depends on the stepping, and that the external interfaces > are all the same (voltage, clock speed for memory and I/O, > etc.). > > PIII's can run this way, for sure. This is a perfect example of, "Just because you can do something, doesn't mean you should." I wouldn't see anything wrong with grabbing the clock frequency of the first cpu in the system and noting in the man page that if you have multiple cpus and you aren't running them at the same frequency, then the reported value is applicable only to the first cpu. This would save a ton of time in implementing Jordan's ideas, at the cost of not being able to deal correctlywith a situation that (hopefully) isn't too common in the field. The other less tangible disadvantage to my suggestion is that it takes us one step further in our single-cpu-centric userland, ala top, uptime, and so forth only displaying stats for "one" cpu. Josh > > If you want to find out who's doing it, you only need to search > the SMP list archives; it wasn't important enough for me to commit > the message to memory, I only remember the fact that someone was > doing it successfully. > > -- Terry > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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