Re: threads

From: J . A . Magallon (jamagallon@able.es)
Date: Tue Mar 06 2001 - 19:07:34 EST


On 03.07 Ying Chen wrote:
> 2. We ran multi-threaded application using Linux pthread library on 2-way
> SMP and UP intel platforms (with both 2.2 and 2.4 kernels). We see
> significant increase in context switching when moving from UP to SMP, and
> high CPU usage with no performance gain in turns of actual work being done
> when moving to SMP, despite the fact the benchmark we are running is
> CPU-bound. The kernel profiler indicates that the a lot of kernel CPU ticks
> went to scheduling and signaling overheads. Has anyone seen something like
> this before with pthread applications running on SMP platforms? Any
> suggestions or pointers on this subject?
>

Too much contention ? How frequently do you create and destroy threads ?
How much frequently do they access shared-writable-data ?
How do you protect them ?

It seems like your system spents more time creating and killing threads
that doing real work.

-- 
J.A. Magallon                                                      $> cd pub
mailto:jamagallon@able.es                                          $> more beer

Linux werewolf 2.4.2-ac13 #3 SMP Wed Mar 7 00:09:17 CET 2001 i686

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