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Re: A new algorithm for for a distributed priority and ,non priority LOCK...

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Hello,

Be smart please, to reduce a lot the cache-coherence traffic,
you have to choose a queue that reduces a lot the cache-coherence 
traffic, and for that you have to code a queue as a linklist
(similar to to the MCS queue) that reduces a lot the cache-coherence 
traffic, but you have to avoid the lockfree queues cause they will 
higher the cache-coherence. This is how you have to code my distributed 
LOCK and it will efficient and be good.



Thank you,
Amine Moulay Ramdane.









On 9/24/2013 11:48 AM, aminer wrote:
>
> I correct some typos, please read again...
>
> Hello,
>
> Here is my new algorithm for a distributed priority and
> non priority LOCK, this algorithm reduce a lot the
> cache-coherence  traffic and is good, so follow me please...
>
>
> First you you allocate an array with the same number of elements
> as the numbers of cores and the elements in the array must be 64 bytes
> cache aligned and must be a record containing one element that is the
> a flag for the first CAS that will be used as a critical section .
>
> You first initialise the distributed priority LOCK by setting
> a flag for the second CAS that will be used as a critical section to 0
> and you set the flag of the first CAS that will be used also as a
> critical section to 1 (to permit the first thread to enter the lock())
>
> The lock() function will look like this:
>
> Every thread that enters the lock() must acquire his processor
> number by using GetProcessorNumber() function, but this function
> will be optimized to amortize the number of calls to it, and that's
> easy to do.
>
> You enter the lock() function by pushing the processor number of the
> threads into a queue or priority queue that will be optimized, this
> queue will be using a CAS on the push() and will not use any CAS on the
> pop(), we don't need it on the pop() cause only one thread will pop()
> from the unlock() function, after that you enter a repeat loop where you
> test with the first CAS and you test also with the second CAS the flag
> of the corresponding element(flag) of the array using the processor
> number of the threads as an index , the flag for the second CAS will be
> set to 1 so the first thread will enter the lock() and the other threads
> will test in a repeat loop for the first CAS and the second CAS and
> there flags will have been set to zero so they will wait..
>
> After that the first thread will arrive to the unlock() function and
> he will pop() the processor number from the optimized priority queue
> or non priority queue and set the flag for the first CAS to 1 for the
> corresponding processor core this will allow a thread to enter the lock
> , if there is no elements in the queue the thread will set the flag of
> the second CAS to 1 and this will allow a thread to enter the lock.
>
>
> So as you have noticed my algorithm is efficient also cause if there
> is threads waiting, the cache-coherence traffic will be reduced a lot
> cause we are using local variables in each element of the array alligned
> to 64 byte.
>
>
> So if you have noticed, in fact i am using 2 CASes , so my algorithm
> is good.
>
> This was my algorithm for a distributed priority and non priority LOCK
> that is efficient, and i will code it as soon as possible.
>
>
>
> Thank you,
> Amine Moulay Ramdane.
>

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Thread

A new algorithm for for a distributed priority and ,non priority LOCK... aminer <aminer@toto.net> - 2013-09-24 10:33 -0700
  Re: A new algorithm for for a distributed priority and ,non priority LOCK... aminer <aminer@toto.net> - 2013-09-24 11:44 -0700
  Re: A new algorithm for for a distributed priority and ,non priority LOCK... aminer <aminer@toto.net> - 2013-09-24 11:48 -0700
    Re: A new algorithm for for a distributed priority and ,non priority LOCK... aminer <aminer@toto.net> - 2013-09-24 12:40 -0700
    Re: A new algorithm for for a distributed priority and ,non priority LOCK... aminer <aminer@toto.net> - 2013-09-24 12:44 -0700

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