Re: polyForth multitasker question

From	anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups	comp.lang.forth
Subject	Re: polyForth multitasker question
Date	2017-04-14 11:31 +0000
Organization	Institut fuer Computersprachen, Technische Universitaet Wien
Message-ID	<2017Apr14.133103@mips.complang.tuwien.ac.at> (permalink)
References	(6 earlier) <mqGdnYQe2bgs-W3FnZ2dnUU7-IXNnZ2d@supernews.com> <ocpr1b$p4b$1@dont-email.me> <6_ydnXUzTNeS523FnZ2dnUU7-THNnZ2d@supernews.com> <2017Apr14.095322@mips.complang.tuwien.ac.at> <-MadnS8jLJDXEW3FnZ2dnUU7-RHNnZ2d@supernews.com>

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"Elizabeth D. Rather" <erather@forth.com> writes:
>On 4/13/17 9:53 PM, Anton Ertl wrote:
>> "Elizabeth D. Rather" <erather@forth.com> writes:
>>> In fact, it's far less complicated than that. Each task knows how long
>>> it's sleeping, and each time around the round-robin checks to see if it's
>>> wake-up time yet. A very few instructions each time.
>>
>> If you have 100 tasks waiting in MS, that's maybe 1000 instructions
>> and 100 cache line touches (20% of the L1 cache of a recent Intel CPU)
>> every time a working task PAUSEs.  And if you have 1000 such tasks,
>> every PAUSE scrubs the L1 cache and causes 1000 L1 cache misses (i.e.,
>> about 50000 cycles from the cache misses alone).  It's simple, but it
>> does not scale.
>>
>> And it burns CPU when everything is waiting.
>
>Fortunately such scenarios are rare (I've only seen 100 tasks a couple 
>of times).

Of course, when your multi-tasker does not scale, programmers avoid
using many tasks.  By contrast, Erlang has implemented scalable
multi-tasking and demonstrated it with 85,000 tasks (processes in
Erlang terminology) in
<http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.116.1969&rep=rep1&type=pdf>
in order to suppoort concurrency-oriented programming.

>I certainly prefer a scenario where a task can initiate a process that 
>will interrupt when it is complete, as that's much more efficient than 
>polling.

You lost me here.  You have argued that polling the current time in
each task is the right way to implement MS, now you argue that the
approach that others have advocated is preferable.  Either I
misunderstand what you mean, or you are silently changing your
position.

- anton
-- 
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
     New standard: http://www.forth200x.org/forth200x.html
   EuroForth 2016: http://www.euroforth.org/ef16/

Thread

polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-08 20:53 +1000
  Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-08 12:29 -0500
    Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-10 09:50 +1000
      Re: polyForth multitasker question David Schultz <abuse@127.0.0.1> - 2017-04-09 19:25 -0500
        Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-10 10:52 +1000
          Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-10 08:58 -0500
            Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-15 10:39 +1000
        Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-11 11:12 +1000
          Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-10 18:22 -0700
            Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-11 12:17 +1000
          Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-11 03:10 -0500
      Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-09 14:37 -1000
        Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-09 18:05 -0700
          Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-09 15:50 -1000
          Re: polyForth multitasker question Lars Brinkhoff <lars.spam@nocrew.org> - 2017-04-10 07:47 +0200
        Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-10 12:20 +1000
        Re: polyForth multitasker question Alex <alex@rivadpm.com> - 2017-04-10 09:11 +0100
          Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-10 04:20 -0500
            Re: polyForth multitasker question Alex <alex@rivadpm.com> - 2017-04-10 10:53 +0100
              Re: polyForth multitasker question Alex <alex@rivadpm.com> - 2017-04-10 11:24 +0100
              Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-11 12:05 +1000
                Re: polyForth multitasker question Alex <alex@rivadpm.com> - 2017-04-11 14:27 +0100
                Re: polyForth multitasker question minforth@arcor.de - 2017-04-11 07:08 -0700
                Re: polyForth multitasker question foxaudioresearch@gmail.com - 2017-04-11 18:06 -0700
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-11 18:58 -0700
                Re: polyForth multitasker question foxaudioresearch@gmail.com - 2017-04-12 13:57 -0700
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-12 18:02 -0700
                Re: polyForth multitasker question foxaudioresearch@gmail.com - 2017-04-12 19:47 -0700
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-12 21:22 -0700
                Re: polyForth multitasker question foxaudioresearch@gmail.com - 2017-04-13 02:57 -0700
                Re: polyForth multitasker question minforth@arcor.de - 2017-04-12 23:17 -0700
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-13 00:13 -0700
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-13 09:43 -1000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-13 19:34 -0700
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-13 19:57 -1000
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-14 02:45 -0400
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-13 21:28 -1000
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-14 07:53 +0000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-14 01:44 -0700
                Re: polyForth multitasker question minforth@arcor.de - 2017-04-14 02:01 -0700
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-14 11:28 -0700
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-14 16:23 -0400
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-13 22:46 -1000
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-14 11:31 +0000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-14 11:23 -0700
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-14 10:06 -1000
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-14 08:13 -0500
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-14 14:12 +0000
                Re: polyForth multitasker question pahihu <pahihu@gmail.com> - 2017-04-14 09:30 -0700
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-15 08:46 +0000
                Re: polyForth multitasker question pahihu <pahihu@gmail.com> - 2017-04-15 13:07 -0700
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-15 17:27 -0700
                Re: polyForth multitasker question foxaudioresearch@gmail.com - 2017-04-15 18:18 -0700
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-17 13:53 +0000
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-14 11:34 -0500
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-14 11:31 -0700
                Re: polyForth multitasker question Julian Fondren <julian.fondren@gmail.com> - 2017-04-14 12:14 -0700
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-14 12:46 -0700
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-14 12:48 -0700
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-14 12:50 -0700
                Re: polyForth multitasker question albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2017-04-15 14:39 +0200
                Re: polyForth multitasker question Julian Fondren <julian.fondren@gmail.com> - 2017-04-15 11:48 -0700
                Re: polyForth multitasker question Alex <alex@rivadpm.com> - 2017-04-14 22:07 +0100
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-15 16:47 +0000
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-15 11:36 -1000
                Re: polyForth multitasker question foxaudioresearch@gmail.com - 2017-04-15 17:07 -0700
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-15 14:17 -1000
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-15 18:27 -0700
                Re: polyForth multitasker question Ron Aaron <rambamist@gmail.com> - 2017-04-16 06:53 +0300
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-15 22:00 -0700
                Re: polyForth multitasker question Ron Aaron <rambamist@gmail.com> - 2017-04-16 08:59 +0300
                Re: polyForth multitasker question lehs <skydda.barnen@gmail.com> - 2017-04-15 22:19 -0700
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-15 17:26 -0700
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-16 09:10 -0500
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-16 09:13 -1000
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-16 16:28 +0000
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-16 09:27 -1000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-16 14:45 -0700
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-16 17:50 -1000
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-17 12:13 +0000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-17 13:27 -0700
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-18 03:49 -0500
                Re: polyForth multitasker question Alex <alex@rivadpm.com> - 2017-04-18 13:47 +0100
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-18 14:30 -0500
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-16 20:58 -0700
                Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-18 11:47 +1000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-17 19:19 -0700
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-18 04:34 -0500
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-19 02:00 -0700
                Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-19 18:10 +1000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-19 01:41 -0700
                Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-19 21:38 +1000
                Re: polyForth multitasker question Lars Brinkhoff <lars.spam@nocrew.org> - 2017-04-19 10:56 +0200
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-19 07:22 -0500
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-17 20:10 -0700
                Re: polyForth multitasker question stephen@mpeforth.com (Stephen Pelc) - 2017-04-18 09:35 +0000
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-18 08:01 -0700
                Re: polyForth multitasker question Julian Fondren <julian.fondren@gmail.com> - 2017-04-18 09:03 -0700
                Re: polyForth multitasker question Cecil Bayona <cbayona@cbayona.com> - 2017-04-18 11:07 -0500
                Re: polyForth multitasker question Cecil Bayona <cbayona@cbayona.com> - 2017-04-18 10:59 -0500
                Re: polyForth multitasker question "HAA" <someone@microsoft.com> - 2017-04-19 19:13 +1000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-15 17:36 -0700
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-16 16:27 +0000
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-16 04:32 -0500
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-14 10:15 -1000
                Re: polyForth multitasker question albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2017-04-15 13:07 +0200
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-17 15:13 +0000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-14 01:36 -0700
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-13 22:48 -1000
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-14 16:36 -0400
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-14 14:55 -0700
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-14 15:27 -0700
                Re: polyForth multitasker question Alex <alex@rivadpm.com> - 2017-04-14 23:45 +0100
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-16 21:13 -0700
                Re: polyForth multitasker question Alex <alex@rivadpm.com> - 2017-04-17 16:57 +0100
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-17 20:08 -0700
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-14 20:29 -0400
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-14 15:34 -1000
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-14 19:43 -0700
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-14 23:03 -0400
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-14 23:50 -0700
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-15 03:55 -0400
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-15 01:38 -0700
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-15 11:50 -0400
                Re: polyForth multitasker question john <anon@example.com> - 2017-04-15 12:03 +0100
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-15 12:41 +0000
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-15 12:14 -0400
                Re: polyForth multitasker question Paul Rubin <no.email@nospam.invalid> - 2017-04-15 17:32 -0700
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-15 20:41 -0400
                Re: polyForth multitasker question anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2017-04-17 14:57 +0000
                Re: polyForth multitasker question hughaguilar96@gmail.com - 2017-04-14 20:45 -0700
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-14 23:56 -0400
                Re: polyForth multitasker question albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2017-04-15 14:32 +0200
                Re: polyForth multitasker question rickman <gnuarm@gmail.com> - 2017-04-15 12:05 -0400
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-15 04:10 -0500
                Re: polyForth multitasker question foxaudioresearch@gmail.com - 2017-04-13 03:19 -0700
                Re: polyForth multitasker question Alex <alex@rivadpm.com> - 2017-04-13 15:46 +0100
                Re: polyForth multitasker question foxaudioresearch@gmail.com - 2017-04-14 11:37 -0700
                Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-13 09:48 -1000
                Re: polyForth multitasker question Andrew Haley <andrew29@littlepinkcloud.invalid> - 2017-04-13 05:37 -0500
                Re: polyForth multitasker question minforth@arcor.de - 2017-04-11 22:12 -0700
                Multitasking with Forth processors Lars Brinkhoff <lars.spam@nocrew.org> - 2017-04-12 07:39 +0200
                Re: Multitasking with Forth processors Paul Rubin <no.email@nospam.invalid> - 2017-04-11 22:58 -0700
                Re: Multitasking with Forth processors rickman <gnuarm@gmail.com> - 2017-04-12 03:00 -0400
                Re: Multitasking with Forth processors albert@cherry.spenarnc.xs4all.nl (Albert van der Horst) - 2017-04-12 12:18 +0200
                Re: Multitasking with Forth processors rickman <gnuarm@gmail.com> - 2017-04-12 17:11 -0400
                Re: Multitasking with Forth processors foxaudioresearch@gmail.com - 2017-04-12 13:50 -0700
                Re: Multitasking with Forth processors "Elizabeth D. Rather" <erather@forth.com> - 2017-04-12 13:30 -1000
                Re: Multitasking with Forth processors Jan Coombs <jenfhaomndgfwutc@murmic.plus.com> - 2017-04-14 12:20 +0100
                Re: Multitasking with Forth processors rickman <gnuarm@gmail.com> - 2017-04-14 16:47 -0400
            Re: polyForth multitasker question "Elizabeth D. Rather" <erather@forth.com> - 2017-04-10 07:42 -1000

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