Re: Strange CPU usage times with SMP

Rob Glover (potato@dsnet.com)
Fri, 10 Jan 1997 21:45:33 -0800 (PST)


I don't know if this will rememdy the problem, but you should upgrade your
libc to 5.4.17 immediately, if not sooner ;> aside from POSSIBLY
remedying this problem, it fixes some security bugs, and a lot of other
stuff. :>
-Rob

On Fri, 10 Jan 1997, Chris Griffin wrote:

> I have been running some fairly demainding programs on my Dual PPro 200
> linux box lately and it is great! I am using calles to times() to try to
> get CPU time usage so I can benchmark it against some other platforms I
> work on. The only problem is that when SMP is enabled I get some fairly
> strange times. Sometimes all the time will be system time, other times
> it will all be user time, and as you might have guessed, all combinations
> in-between. If I run this program 5 times, I will get 5 different
> combinations, but they will always add up to the same number Even stranger,
> when I run 2 programs at once, and then look at the output with top, the
> USER CPU is 99% and the system CPU is at 101%. I assume this has to do
> with the fact that I have 2 processors TICKing away. Is this a bug in
> the kernel, C libraries, or just an eventuality that hasn't been taken
> care of yet? In the mean time, does anyone know a way to fix this
> behavior? I am using gcc2.7.2, libc5.3.12, procps 1.01 and linux 2.0.27.
>
> Thanks a lot!
> Chris
>
>