SMP kernels on single processor machines

Lee Braiden lee_b at
Thu May 20 21:48:24 EST 2004

Jens Schmalzing wrote:

>SMP kernels run
>fine on single processor machines.  I have repeatedly been told,
>however, that this bears a considerable performance hit on some
>hardware.  Can anybody confirm or deny this?  Even small hints would
>be appreciated.
A long time ago, I used to compile SMP into my kernels just on the
coolness factor, and on the promise that 'one day, soon, I'll get me a
decent machine' :)

But I quit doing that at some point, after someone (authoritative, but I
can't remember the details) pointed out that it added complexity,
debugging issues, etc.  Given that I *already* have problems with PPC
kernels -- latency/lockups, (preempting?), alsa sound, video res, etc.,
I personally wouldn't go near this until I'm fairly confident that the
other stuff is solid in its own right.

But then, I'm just a luser, not a kernel maintainer ;D

Lee Braiden
lee_b at

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