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large overhead in "manual reset event"

intelbenz
Beginner
‎12-13-2010 09:31 PM
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Just recently I update my tbb 2.1 to tbb 3.0.
And I also switch my pthreads to tbb tasks after reading the
following article

http://software.intel.com/en-us/articles/using-tasks-instead-of-threads/

After taking an analysis on the "locks and waits" I found out that
my program ran slower and having a significant overhead on the
"manual reset event", the wait time was about 6s.

Could anyone what went wrong ?

thanks!

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Dmitry_Vyukov
Valued Contributor I
‎12-13-2010 10:40 PM
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AFAIR, manual reset event is used to park worker threads in TBB. So perhaps your program does not yield enough parallelism, so that some worker threads are parked.
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Dmitry_Vyukov
Valued Contributor I
‎12-13-2010 10:42 PM
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Check the call stack for the wait on manual reset event.
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