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Please read the following....

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  Please read the following.... aminer <aminer@toto.net> - 2014-04-19 19:47 -0700

#2193 — Please read the following....

Hello,


I have discovered a problem today, when you are using a Ticketspinlock
or an array based lock, don't use the "pause" asm instruction only when
you are spinning waiting for the lock or don't use a proportional 
backoff using the "pause" asm instruction only when you are spinning 
waiting for the lock, cause this can lead to a big problem that look 
like a lock convoy, if you start more threads than cores for example the 
system will switch between the threads and giving each thread it's 
quantum time even if the threads don't enter the Enter() method of the 
lock, and this will lead to a big problem , this can slow by much the 
threads entering the lock, this will look like a lock convoy and this is 
not acceptable, so the solution is to use a sleep(0) when you are 
spinning waiting for the lock inside the Enter() method of the lock, but 
i have noticed that sleep(0) lowers a lot the throughput... so this is 
very sad ! so from now on becarefull of this big problem !


Thank you,
Amine Moulay Ramdane.

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