Messages in this thread |  | | From | Sasha Pachev <> | Subject | Strange thread behaviour on 8-way x86 machine | Date | Tue, 3 Jul 2001 12:25:12 -0600 |
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Hi,
I have observed a rather strange behaviour doing a multi-threaded CPU benchmark on an 8-way machine running 2.4.2 SMP kernel. Even when the priority is reniced to the highest possible value, I am still unable to reach more than 50% CPU utilization. My benchmark just creates a bunch of threads with pthread_create(), and then runs a simple integer computation in each thread. On a dual with 2.4.3 kernel, and a 4-way with 2.4.2 kernel, I am able to reach full CPU utilization.
At first glance, it appears to be like some overzealous fairness problem in the scheduler that is exhibited only when you have more than 4 CPUs. Before I start scrutinizing the source trying to understand the inner workings of the scheduler, I would like to get some feedback from people that know something about the subject. Any ideas/suggestions would be appreciated.
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