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From: Jim Geist <velocityboy@gmail.com>
To: Paul Winalski <paul.winalski@gmail.com>
Cc: The Eunuchs Hysterical Society <tuhs@tuhs.org>,
	Noel Chiappa <jnc@mercury.lcs.mit.edu>
Subject: Re: [TUHS] Memory management in Dennis Ritchie's C Compiler
Date: Mon, 17 Aug 2020 15:35:47 -0400	[thread overview]
Message-ID: <CAJohCK+EbnA8ESapTtD7wE7sdGGLCNzz3bFpQu=BaQsy1m9jog@mail.gmail.com> (raw)
In-Reply-To: <CABH=_VS8mHAADKmxtinBQ1Y87suN3rLd2Cj=4mD4FmACN8dQtQ@mail.gmail.com>

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True, but zones and HeapAlloc do a fair bit of work to handle objects of
multiple sizes. If you're partitioning up a page and you know every object
on the page is 8 or 16 or 48 bytes, it's MUCH simpler. And a lot of the
data structures in a compiler tend to be small-tens-of-bytes nodes.

On Mon, Aug 17, 2020 at 3:28 PM Paul Winalski <paul.winalski@gmail.com>
wrote:

> On 8/17/20, Jim Geist <velocityboy@gmail.com> wrote:
> > When did mmap(2) come about? Another thing I've seen is building a small
> > block allocator on top of that. You can guarantee that all your objects
> are
> > nicely collected into the same set of pages for locality with very little
> > overhead.
> >
> mmap(2) certainly can be used to allocate blocks for the mini-heap
> itself, but you still have to write your own equivalents of malloc()
> and free() to allocate data structures within the mini-heap.  The nice
> thing about VMS heap zones and Microsoft's private heaps is that you
> get the malloc()/free() layer off-the-shelf; you don't have to roll
> your own.
>
> -Paul W.
>

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  reply	other threads:[~2020-08-17 19:36 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-17  2:02 Noel Chiappa
2020-08-17 18:02 ` Paul Winalski
2020-08-17 18:13   ` Jim Geist
2020-08-17 18:48     ` Paul Winalski
2020-08-17 19:08       ` Jim Geist
2020-08-17 19:28         ` Paul Winalski
2020-08-17 19:35           ` Jim Geist [this message]
2020-08-17 19:41             ` Richard Salz
2020-08-17 23:40               ` Steffen Nurpmeso
  -- strict thread matches above, loose matches on Subject: below --
2020-08-27  8:37 Paul Ruizendaal
2020-08-26 15:59 Noel Chiappa
2020-08-26 16:09 ` Warner Losh
2020-08-26 19:13   ` Clem Cole
2020-08-26 16:14 ` Jim Geist
2020-08-26 17:31 ` John Cowan
2020-08-26 13:24 Doug McIlroy
2020-08-26 15:41 ` John Cowan
2020-08-25  9:36 Steve Simon
2020-08-17 22:32 Norman Wilson
2020-08-17 22:55 ` Bakul Shah
2020-08-17 23:12 ` Chet Ramey
2020-08-18  6:33 ` arnold
2020-08-17 19:51 Noel Chiappa
2020-08-17 19:27 Noel Chiappa
2020-08-17 19:30 ` Larry McVoy
2020-08-17 19:44   ` Dan Halbert
2020-08-17 19:50   ` Paul Winalski
2020-08-17 22:05     ` Arthur Krewat
2020-08-18  0:52 ` Rob Gingell
2020-08-15 21:50 Dibyendu Majumdar
2020-08-16 15:20 ` arnold
2020-08-16 15:27   ` Jim Geist
2020-08-17 16:13 ` Dan Cross
2020-08-17 20:16   ` Dibyendu Majumdar
2020-08-17 20:34     ` Paul Winalski
2020-08-17 20:43       ` Dibyendu Majumdar
2020-08-17 21:05         ` Warner Losh
2020-08-17 22:47         ` Dave Horsfall
2020-08-17 23:06           ` Nemo Nusquam
2020-08-17 21:29     ` Dibyendu Majumdar
2020-08-24 15:58     ` Dan Cross
2020-08-24 17:08       ` John Cowan
2020-08-24 17:15         ` Clem Cole
2020-08-24 17:24           ` Clem Cole
2020-08-24 17:20         ` Dan Cross
2020-08-25 23:06           ` Arthur Krewat

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