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Re: Things have 'moved on' apparently

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On 11/8/2015 6:24 PM, Martin Gregorie wrote:
> On Sun, 08 Nov 2015 17:05:47 -0500, Arne Vajhøj wrote:
>
>> On 11/8/2015 4:12 PM, Martin Gregorie wrote:
>>> In this case the offending functions were the malloc and B-tree modules
>>> in the C standard library for DEC's Alpha servers running TrueUNIX.
>>>
>>> The root problem was that the OS was Mach-based and the implementation
>>> seemed to use a single-threaded process to implement each low level
>>> clib function: at least, we found this problem in several parts of the
>>> OS. Maybe this is the main reason that Mach message-passing
>>> micro-kernel architectures have largely disappeared, but I digress...
>>>
>>> The effect was that, because the btree routine used three chunks of
>>> memory for each node (IIRC one for key, one for data, one for the three
>>> pointers), so that lookups (which added unknown nodes to the tree)
>>> bottle-
>>> necked on the malloc() process with three calls per node added. We
>>> needed something like 7,000 lookups/sec but couldn't break 800.
>>>
>>> So I rewrote the btree functions to use only one struct per node, which
>>> gave an immediate speedup to better than 1500 lookups/sec.
>>>
>>> More checks showed that now the sbrk() function that malloc() called
>>> each time it needed to extend process heap memory had the same problem.
>>> So, I changed my code to use malloc() to grab MB-sized chunks of heap
>>> space and and wrote an application level function that allocated btree
>>> nodes in my chunk of heap and asked for more when it was needed. This
>>> gave me 25,000 looks/sec: job done!
>>
>> Isn't that what __mingrow was supposed to do in a more transparent way?
>>
> 'locate' doesn't find __mingrow (or mingrow) in my development
> environment. The pnly references I can find are in relation to a C#
> priority queue: this all happened long before C# existed.

http://www3.physnet.uni-hamburg.de/physnet/Tru64-Unix/HTML/MAN/MAN3/0892____.HTM

Arne

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Things have 'moved on' apparently Eternal Hope <laughingspam99@gmail.com> - 2015-11-06 12:32 +0000
  Re: Things have 'moved on' apparently Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2015-11-06 08:25 -0800
    Re: Things have 'moved on' apparently Eric Douglas <e.d.programmer@gmail.com> - 2015-11-06 12:02 -0800
      Re: Things have 'moved on' apparently Jerry Stuckle <jstucklex@attglobal.net> - 2015-11-06 19:46 -0500
        Re: Things have 'moved on' apparently Martin Gregorie <martin@address-in-sig.invalid> - 2015-11-07 17:21 +0000
          Re: Things have 'moved on' apparently Jerry Stuckle <jstucklex@attglobal.net> - 2015-11-07 12:50 -0500
        Re: Things have 'moved on' apparently Eric Douglas <e.d.programmer@gmail.com> - 2015-11-09 05:37 -0800
          Re: Things have 'moved on' apparently Jerry Stuckle <jstucklex@attglobal.net> - 2015-11-09 09:00 -0500
          Re: Things have 'moved on' apparently Martin Gregorie <martin@address-in-sig.invalid> - 2015-11-09 14:56 +0000
          Re: Things have 'moved on' apparently Martin Gregorie <martin@address-in-sig.invalid> - 2015-11-09 19:25 +0000
      Re: Things have 'moved on' apparently Arne Vajhøj <arne@vajhoej.dk> - 2015-11-07 21:57 -0500
    Re: Things have 'moved on' apparently Arne Vajhøj <arne@vajhoej.dk> - 2015-11-07 22:02 -0500
      Re: Things have 'moved on' apparently leif.roar@dimnakorr.com - 2015-11-08 02:00 -0600
        Re: Things have 'moved on' apparently Arne Vajhøj <arne@vajhoej.dk> - 2015-11-08 08:44 -0500
          Re: Things have 'moved on' apparently leif.roar@dimnakorr.com - 2015-11-08 13:08 -0600
        Re: Things have 'moved on' apparently Robert Klemme <shortcutter@googlemail.com> - 2015-11-08 18:54 +0100
          Re: Things have 'moved on' apparently Martin Gregorie <martin@address-in-sig.invalid> - 2015-11-08 21:12 +0000
            Re: Things have 'moved on' apparently Arne Vajhøj <arne@vajhoej.dk> - 2015-11-08 17:05 -0500
              Re: Things have 'moved on' apparently Martin Gregorie <martin@address-in-sig.invalid> - 2015-11-08 23:24 +0000
                Re: Things have 'moved on' apparently Arne Vajhøj <arne@vajhoej.dk> - 2015-11-08 19:40 -0500
                Re: Things have 'moved on' apparently Jerry Stuckle <jstucklex@attglobal.net> - 2015-11-08 21:32 -0500
                Re: Things have 'moved on' apparently Martin Gregorie <martin@address-in-sig.invalid> - 2015-11-09 15:15 +0000
      Re: Things have 'moved on' apparently Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2015-11-08 12:10 -0800
        Re: Things have 'moved on' apparently Jerry Stuckle <jstucklex@attglobal.net> - 2015-11-08 16:00 -0500
        Re: Things have 'moved on' apparently Arne Vajhøj <arne@vajhoej.dk> - 2015-11-08 16:51 -0500
  Re: Things have 'moved on' apparently Jan Burse <janburse@fastmail.fm> - 2015-11-08 00:55 +0100
  Re: Things have 'moved on' apparently Arne Vajhøj <arne@vajhoej.dk> - 2015-11-07 21:28 -0500
    Re: Things have 'moved on' apparently Arne Vajhøj <arne@vajhoej.dk> - 2015-11-07 21:36 -0500
  Re: Things have 'moved on' apparently leif.roar@dimnakorr.com - 2015-11-08 02:12 -0600
  Re: Things have 'moved on' apparently askfor <askfor@nowhere.net> - 2015-11-09 18:02 +0100
  Re: Things have 'moved on' apparently Kevin McMurtrie <mcmurtrie@pixelmemory.us> - 2015-11-10 22:32 -0800
    Re: Things have 'moved on' apparently Eternal Hope <laughingspam99@gmail.com> - 2015-11-11 07:52 +0000
      Re: Things have 'moved on' apparently ross.finlayson@gmail.com - 2015-11-19 23:28 -0800

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