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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Beware: Rep spec on an enumeration type causes code explosion
Date: 1997/12/10
Date: 1997-12-10T00:00:00+00:00	[thread overview]
Message-ID: <dewar.881730252@merv> (raw)
In-Reply-To: gwinn-0812971217080001@dh5055133.res.ray.com


Joe said

<<As I said in my reply to Tucker Taft, our experience is that only
fixed-block allocators work in embedded realtime, especially when the
system is heavily loaded.  Such allocators have constant performance,
right up to the point of pool exhaustion, and recover instantly when
someone returns some memory.  Variable block allocators as a class run
slower and slower as their pool approaches exhaustion; this is exactly the
wrong behaviour, as it makes worse the effects of the original overload.
>>

This is an over-generalization, there are algorithms known that provide
variable size allocation with constant performance. These algorithms are
the ones that should be used for real time performance.





  reply	other threads:[~1997-12-10  0:00 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1997-12-05  0:00 Beware: Rep spec on an enumeration type causes code explosion Joe Gwinn
1997-12-06  0:00 ` Robert Dewar
1997-12-08  0:00   ` Joe Gwinn
1997-12-09  0:00     ` Stanley R. Allen
1997-12-06  0:00 ` Robert Dewar
1997-12-06  0:00 ` Corey Minyard
1997-12-08  0:00   ` Joe Gwinn
1997-12-10  0:00     ` Robert Dewar [this message]
1997-12-06  0:00 ` Ken Garlington
1997-12-06  0:00 ` Kevin D. Heatwole
     [not found]   ` <dewar.881478386@merv>
1997-12-07  0:00     ` Robert Dewar
1997-12-09  0:00   ` Jim Gleason
1997-12-06  0:00 ` Tucker Taft
1997-12-06  0:00   ` Robert Dewar
1997-12-06  0:00   ` Robert Dewar
1997-12-08  0:00   ` Joe Gwinn
1997-12-08  0:00     ` Mats Weber
1997-12-09  0:00     ` Geert Bosch
1997-12-10  0:00       ` Robert Dewar
1997-12-09  0:00     ` Tucker Taft
1997-12-09  0:00       ` Matthew Heaney
1997-12-10  0:00         ` Charles Hixson
1997-12-10  0:00       ` Ken Garlington
1997-12-11  0:00         ` John G. Volan
1997-12-11  0:00           ` Ken Garlington
1997-12-12  0:00             ` Matthew Heaney
1997-12-12  0:00               ` Ken Garlington
1997-12-16  0:00                 ` John G. Volan
1997-12-17  0:00                   ` Ken Garlington
1997-12-12  0:00           ` Joe Gwinn
1997-12-12  0:00             ` Robert Dewar
1997-12-16  0:00             ` John G. Volan
1997-12-17  0:00               ` Joe Gwinn
1997-12-17  0:00                 ` John G. Volan
1997-12-18  0:00                   ` Joe Gwinn
1997-12-17  0:00               ` Ken Garlington
1997-12-12  0:00           ` Alan E & Carmel J Brain
1997-12-12  0:00             ` Robert Dewar
1997-12-15  0:00               ` Tucker Taft
1997-12-16  0:00                 ` Brian Rogoff
1997-12-10  0:00       ` Stephen Leake
1997-12-14  0:00         ` Robert Dewar
1997-12-10  0:00       ` Stanley R. Allen
1997-12-14  0:00         ` Robert Dewar
1997-12-10  0:00       ` Robert Dewar
1997-12-10  0:00       ` Jean-Pierre Rosen
1997-12-11  0:00       ` Rakesh Malhotra
1997-12-11  0:00         ` Matthew Heaney
1997-12-12  0:00           ` Robert Dewar
1997-12-12  0:00           ` Rakesh Malhotra
1997-12-12  0:00           ` Samuel Tardieu
1997-12-12  0:00             ` Robert Dewar
1997-12-14  0:00         ` Alan E & Carmel J Brain
1997-12-12  0:00       ` Joe Gwinn
1997-12-15  0:00         ` Robert Dewar
1997-12-16  0:00           ` Joe Gwinn
1997-12-16  0:00             ` Robert Dewar
1997-12-06  0:00 ` David Marshall
1997-12-06  0:00 ` Robert Dewar
1997-12-06  0:00   ` Matthew Heaney
1997-12-10  0:00   ` GNORT information ( Was Re: Beware: Rep spec on an enumeration type causes code explosion ) Mark Bennison
1997-12-10  0:00     ` Robert Dewar
1997-12-06  0:00 ` Beware: Rep spec on an enumeration type causes code explosion Robert Dewar
1997-12-08  0:00   ` Joe Gwinn
1997-12-06  0:00 ` Robert Dewar
1997-12-07  0:00 ` Larry Kilgallen
  -- strict thread matches above, loose matches on Subject: below --
1997-12-09  0:00 tmoran
1997-12-11  0:00 Marin David Condic, 561.796.8997, M/S 731-96
1997-12-11  0:00 Marin David Condic, 561.796.8997, M/S 731-96
1997-12-11  0:00 ` Robert Dewar
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