From: Andy Wingo <wingo@pobox.com>
To: Mark H Weaver <mhw@netris.org>
Cc: guile-devel@gnu.org
Subject: Re: Whats' the proper senario of par-map? (Was Re: bug#13188: par-map causes VM stack overflow)
Date: Mon, 01 Apr 2013 21:10:32 +0200 [thread overview]
Message-ID: <87y5d2cbiv.fsf@pobox.com> (raw)
In-Reply-To: <87d2uiah6h.fsf@tines.lan> (Mark H. Weaver's message of "Fri, 29 Mar 2013 01:49:58 -0400")
On Fri 29 Mar 2013 06:49, Mark H Weaver <mhw@netris.org> writes:
>> scheme@(guile-user)> ,time (define a (map (lambda (x) (expt x 5)) (iota
>> 10000)))
>> ;; 0.008019s real time, 0.007979s run time. 0.000000s spent in GC.
>> scheme@(guile-user)> ,time (define a (par-map (lambda (x) (expt x 5))
>> (iota 10000)))
>> ;; 6.596471s real time, 6.579375s run time. 1.513880s spent in GC.
>
> The timings above suggest that, on your machine, the overhead of
> 'par-map' is in the neighborhood of 660 microseconds per thread (that's
> the total run time divided by 10000 iterations).
Per item, you mean? Anyway this seems like a really high overhead, and
we shouldn't make too many excuses for it ;)
Andy
--
http://wingolog.org/
next prev parent reply other threads:[~2013-04-01 19:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1355559152.27310.5.camel@Renee-desktop.suse>
[not found] ` <87y5d8rclr.fsf@gnu.org>
2013-03-28 2:55 ` Whats' the proper senario of par-map? (Was Re: bug#13188: par-map causes VM stack overflow) Nala Ginrut
2013-03-28 5:05 ` Mark H Weaver
2013-03-28 13:44 ` Ludovic Courtès
2013-03-28 18:00 ` Mark H Weaver
2013-03-28 20:07 ` Ludovic Courtès
2013-03-29 2:36 ` Nala Ginrut
2013-03-29 5:49 ` Mark H Weaver
2013-03-29 6:00 ` Extremely high overhead of 'par-map' Mark H Weaver
2013-03-29 20:24 ` Noah Lavine
2013-03-29 20:27 ` Noah Lavine
2013-03-29 23:18 ` Mark H Weaver
2013-03-30 23:37 ` Ludovic Courtès
2013-03-29 16:45 ` Whats' the proper senario of par-map? (Was Re: bug#13188: par-map causes VM stack overflow) Mark H Weaver
2013-04-01 19:10 ` Andy Wingo [this message]
2013-03-29 9:52 ` Ludovic Courtès
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