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Re: map-par slower than map
From: |
Olivier Dion |
Subject: |
Re: map-par slower than map |
Date: |
Thu, 13 Oct 2022 05:10:54 -0400 |
On Thu, 13 Oct 2022, Damien Mattei <damien.mattei@gmail.com> wrote:
> ok , i think the problem comes both from my code and from guile parmap so.
> Obviously parmap could be slower on other codes because of the nature of
> list i think, it is hard to split a list in sublist and send them to thread
> and after redo a single list, i better use vector.
> As mentioned and forget by me, i apologize, i use an hash table which is a
> global variable and mutex can be set on it , no dead lock , here but it
> slow down the code than it is dead for speed , but not locked.
Your code is not the issue. The fact that `(par-map 1+ (iota
10000000))` is slow is the proof of that. I think that you should use
par-map when you want to do I/O/subprocesses in parallel. Fast
computation on a huge number of items should be done with vector because
of its random access nature. List are simply no the good data structure
for parallelization.
> The examples given are good but i do not want to write long and specific
> code for //, for // must a ssimple as OpenMP directives (on arrays) not be
> a pain in the ass like things i already did at work with GPUs in C or
> Fortran,that's nightmare and i do not want to have this in functional
> programming.
You're free to use my example of `par-map-vector` and tweak it to your needs.
But maybe it's time for a `guile-parallel` for fast high level
parallel. If others are interested in that, I can make one.
--
Olivier Dion
oldiob.dev
- Re: map-par slower than map, (continued)
- Re: map-par slower than map, Damien Mattei, 2022/10/24
- Re: map-par slower than map, Mikael Djurfeldt, 2022/10/25
- Re: map-par slower than map, Mikael Djurfeldt, 2022/10/25
- Re: map-par slower than map, Damien Mattei, 2022/10/25
- Re: map-par slower than map, Maxime Devos, 2022/10/12
Re: map-par slower than map, Olivier Dion, 2022/10/12
- Re: map-par slower than map, Damien Mattei, 2022/10/13
- Re: map-par slower than map, Damien Mattei, 2022/10/13
- Re: map-par slower than map, Olivier Dion, 2022/10/13
- Message not available
- Fwd: map-par slower than map, Damien Mattei, 2022/10/13
- Re: map-par slower than map, Damien Mattei, 2022/10/13
- Re: map-par slower than map, Olivier Dion, 2022/10/13
- Re: map-par slower than map, Damien Mattei, 2022/10/13
- Re: map-par slower than map, Olivier Dion, 2022/10/13
- Re: map-par slower than map, Damien Mattei, 2022/10/13
- Re: map-par slower than map, Damien Mattei, 2022/10/13