From: Paul Rubin <no.email@nospam.invalid>
Subject: Re: Toy computational "benchmark" in Ada (new blog post)
Date: Thu, 06 Jun 2019 21:50:04 -0700
Date: 2019-06-06T21:50:04-07:00 [thread overview]
Message-ID: <877e9yxamb.fsf@nightsong.com> (raw)
In-Reply-To: 87blzaxnei.fsf@nightsong.com
Paul Rubin <no.email@nospam.invalid> writes:
> Actual elapsed times were 2 min 5 sec for the single threaded [Ada]
> version and 36.484s for the parallel version. The reported usermode
> cpu times were 2m3.2s for the single threaded version and 2m18s
> (across the 4 cores) for the parallel version.
>
> I'll see if I can code and time a C++ version.
C++ version results: single threaded 45.73 seconds cpu, 47.36 sec elapsed.
Multi-threaded (4 threads): 84.34 sec cpu, 23.11 sec elapsed.
That's using GCC 6.03 with threading done by std::future's async
function. So both versions are a fair amount faster than the Ada
version, but the threading speedup is nowhere near as good. I wonder
what's going on with that. At each of the 50 calculation runs, I launch
4 threads for slices of the array, then wait for them to complete and
sum the results, so there might be a little bit of idle time if the
threads don't all use the exact same amount of time.
I also want to try with transform_map_reduce and maybe the new Intel TBB
library with GCC 9. It is possible that transform_map_reduce can use
Intel SIMD intrinsics but otherwise they can be called directly with
some hassle. Also I can run on a machine with AVX512.
I guess the next thing after that would be OpenCL or CUDA and a graphics
card.
next prev parent reply other threads:[~2019-06-07 4:50 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-06 11:05 Toy computational "benchmark" in Ada (new blog post) David Trudgett
2019-06-06 17:48 ` Olivier Henley
2019-06-06 23:14 ` David Trudgett
2019-06-06 23:27 ` Paul Rubin
2019-06-07 5:24 ` David Trudgett
2019-06-07 5:36 ` Paul Rubin
2019-06-06 20:31 ` Jeffrey R. Carter
2019-06-06 23:02 ` David Trudgett
2019-06-07 0:13 ` Paul Rubin
2019-06-07 4:50 ` Paul Rubin [this message]
2019-06-07 5:41 ` David Trudgett
2019-06-07 6:00 ` Paul Rubin
2019-06-07 6:25 ` David Trudgett
2019-06-07 6:38 ` Paul Rubin
2019-06-07 5:28 ` David Trudgett
2019-06-07 5:57 ` Paul Rubin
2019-06-07 6:21 ` David Trudgett
2019-06-07 6:22 ` Paul Rubin
2019-06-07 6:29 ` David Trudgett
2019-06-07 6:42 ` Paul Rubin
2019-06-07 17:55 ` Jeffrey R. Carter
2019-06-08 11:00 ` David Trudgett
2019-06-07 1:42 ` johnscpg
2019-06-07 5:34 ` David Trudgett
2019-06-08 10:17 ` David Trudgett
2019-06-08 1:14 ` johnscpg
2019-06-08 10:56 ` David Trudgett
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