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Re: Here is again my Proof

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From	blmblm@myrealbox.com <blmblm.myrealbox@gmail.com>
Newsgroups	comp.programming.threads, comp.programming
Subject	Re: Here is again my Proof
Date	18 Oct 2013 18:58:33 GMT
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Cross-posted to 2 groups.

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In article <l36kri$3t3$1@news.albasani.net>, aminer  <aminer@toto.net> wrote:
> 
> I wrote:
>  > Hello,
>  >
>  > I think i know what is my mistake: the serial part in
>  > the Amdahl's law is not the critical section, you must not
>  > confuse the two.
> 

Exactly.  The serial part is the part that must be done exactly once
and cannot be somehow split up among multiple threads or processes.


> 
> But, Amine,  how can you say that the serial part of the Amdahl's law is 
> not
> the critical section ?


Having got it right once (above), why now go off the rails again 
(below) ....

(And why start a new thread for each new thought, rather than keeping
the whole discussion in one thread?)



> In my example if you don't have context switches , and you have the same
> number of threads than the number of cores, and the time inside the 
> critical
> section is constant and the time inside the parallel part is constant, 
> so the Amdahl's law can predict the worst case contention scenario , 
> that means when all the threads are contending for the same critical 
> section, hence you can predict the worst case contention scenario by 
> just  calculating the time inside the critical section and the time 
> inside the parallel part and doing the Amdahl calculation, this will 
> give you the
> exact result for the worst case contention scenario, so as you have
> noticed the serial part of the Amdahl equation is not only the critical 
> section, it's the critical section with a context, so you have to take
> into consideration also the context, that means the context of the worst 
> case contention scenario.
> 
> 
> Thank you,
> Amine Moulay Ramdane.
> 
> 
> 
[ snip ]

-- 
B. L. Massingill
ObDisclaimer:  I don't speak for my employers; they return the favor.

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Here is again my Proof aminer <aminer@toto.net> - 2013-10-09 20:26 -0700
  Re: Here is again my Proof aminer <aminer@toto.net> - 2013-10-09 20:40 -0700
  Re: Here is again my Proof aminer <aminer@toto.net> - 2013-10-09 20:45 -0700
  Re: Here is again my Proof aminer <aminer@toto.net> - 2013-10-09 20:56 -0700
  Re: Here is again my Proof Robert Wessel <robertwessel2@yahoo.com> - 2013-10-10 00:03 -0500
    Re: Here is again my Proof aminer <aminer@toto.net> - 2013-10-10 11:51 -0700
      Re: Here is again my Proof aminer <aminer@toto.net> - 2013-10-10 12:32 -0700
        Re: Here is again my Proof blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2013-10-18 18:58 +0000

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