On Thu, Jun 29, 2000 at 07:09:22PM -0700, William Warner wrote:
>
> Hi,
>
> Here at U of M we have an 8 processor machine with about 3G of RAM. The
> following, _very_ simple program creates 90 threads, in each thread 10M
> is allocated and a simple pointless write is performed on the RAM 10x.
> Now, the program runs just fine on a 1 processor system, but on
> multiprocessors, memory is NOT allocated sometimes (NULL returned
> meaning that the kernel is not re-entrant).
>
> The REAL problem is with the execution speed. If this program is run on
> a multiprocessor system in the bg, and top is executed, the processes
> only get ~15% of the CPU time, and the system gets a whopping 400% and
> about 385% idle. (* processors - 800%).
>
> If I use a fork and multiply processes, the CPU is used about 799%, 1%
> system, 0 idle.
>
> The Question is WHY???? I'm pulling my hair out here! HELP! [I have
> enclosed the source]
>
I didn't seen anything unusual on my 4-way Xeon 400MHz with 4GB. I
am running a modified kernel 2.2.16 and glibc 2.2.
H.J.
-
Linux SMP list: FIRST see FAQ at http://www.irisa.fr/prive/dmentre/smp-howto/
To Unsubscribe: send "unsubscribe linux-smp" to [EMAIL PROTECTED]
