Re: /proc/cpuinfo format - arch dependent!

From: Bill Davidsen
Date: Mon May 09 2005 - 14:25:23 EST


Jim Nance wrote:
On Sat, May 07, 2005 at 01:20:05PM -0400, Dave Jones wrote:

On Sat, May 07, 2005 at 07:05:56PM +0200, Willy Tarreau wrote:


> system "hey, I'd like this type of workload, how many process should
> I start, and where should I bind them ?".

I think generalising this and having a method to do this in the kernel
is a much better idea than each application parsing this themselves.
Things are only getting more and more complex as time goes on,
and I don't trust application developers to get it right.


As a developer of a multiprocess/multithreaded application I can assure
you that you are right not to trust application developers to get this
right. The idea that a programmer understands the behavior of the
applications they write is largely a myth. Furthermore, I suspect
that SMT will evolve in directions that make the idea of a processor
more and more fuzzy. I don't think it is wise to construct any
interface that suggests knowing the hardware details is good, or that
processes should be bound by userland. Certainly it is sometimes
necessary for userland to do this, but we should look at that as a
bug in the kernel.

Might I suggest that if you like the "we know best just trust us" approach, there is another OS to use. Making information available to good applications will improve system performance, or at least allow better limitation of requests for resources, and bad applications will be bad regardless of what you hide. You don't hide the CPU hardware any more than the memory size.

--
-bill davidsen (davidsen@xxxxxxx)
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me
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