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Re: There is still a problem...

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Hello,

I think if the number of threads are not greater than the number
of cores , so the spin-wait for an item in the queue will not be a big 
problem, it will not take too much CPU ressources in each core, so i 
think waitfree algorithms are still usefull.


But lockfree algorithms do not minimize efficiently the cache-coherence 
traffic, they generate too much cache coherence traffic and they
are not FIFO fair , so they are not starvation-free, hence i think they 
are bad.


Thank you,
Amine Moulay Ramdane.



On 10/11/2013 6:52 PM, aminer wrote:
>
> Hello,
>
> We have to be smart, i have invented a waitfree bounded FIFO queue
> and i was writing the algorithm on a paper and thinking at the same
> time, it's true that my new algorithm satisfies the FIFO fairness
> requirement, it also minimizes efficiently the cache-coherence
> traffic... but there is still a problem, this waitfree FIFO queue
> doesn't statisfies a requirement, wich one? when there is no items in
> the queue the threads must not spin-wait cause it's CPU inefficient i
> think,
> and those lockfree and waitfree algorithms must use a spin-wait
> mechanism when there is no items in the queue and they want to wait
> for items in the queue etc. and my new waitfree algorithm must also use
> a spin-wait mechanism in this case, so
> they will take too many CPU ressources if there is no items in
> the queue, so to satisfy this requirement we must use my SemaCondvar
> or a FIFO fair Semaphore  , but this will slow too much the FIFO queue..
> so as you are noticing with me it's not a silver bullet.
>
>
> Hope you have understood my ideas...
>
>
>
> Thank you,
> Amine Moulay Ramdane.
>
>
>
>
>
>
>

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Thread

There is still a problem... aminer <aminer@toto.net> - 2013-10-11 18:52 -0700
  Re: There is still a problem... aminer <aminer@toto.net> - 2013-10-11 19:30 -0700
    Re: There is still a problem... aminer <aminer@toto.net> - 2013-10-11 19:36 -0700
      Re: There is still a problem... aminer <aminer@toto.net> - 2013-10-11 19:46 -0700

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