[src/trunk]: src/lib/libc/stdlib Add history of allocators

[kamil <kamil%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0aeb92279a6e
branches:  trunk
changeset: 339522:0aeb92279a6e
user:      kamil <kamil%NetBSD.org@localhost>
date:      Sun Jul 26 17:09:29 2015 +0000

description:
Add history of allocators

Idea accepted by <christos>
No objctions from <riastradh>

diffstat:

 lib/libc/stdlib/malloc.3 |  48 ++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 46 insertions(+), 2 deletions(-)

diffs (66 lines):

diff -r ac63278f1014 -r 0aeb92279a6e lib/libc/stdlib/malloc.3
--- a/lib/libc/stdlib/malloc.3  Sun Jul 26 17:03:06 2015 +0000
+++ b/lib/libc/stdlib/malloc.3  Sun Jul 26 17:09:29 2015 +0000
@@ -1,4 +1,4 @@
-.\" $NetBSD: malloc.3,v 1.42 2015/07/26 17:00:37 kamil Exp $
+.\" $NetBSD: malloc.3,v 1.43 2015/07/26 17:09:29 kamil Exp $
 .\"
 .\" Copyright (c) 1980, 1991, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -34,7 +34,7 @@
 .\"     @(#)malloc.3   8.1 (Berkeley) 6/4/93
 .\" $FreeBSD: src/lib/libc/stdlib/malloc.3,v 1.73 2007/06/15 22:32:33 jasone Exp $
 .\"
-.Dd February 5, 2015
+.Dd July 26, 2015
 .Dt MALLOC 3
 .Os
 .Sh NAME
@@ -265,3 +265,47 @@
 .Fn free
 functions conform to
 .St -isoC .
+.Sh HISTORY
+A
+.Fn free
+internal kernel function and a predecessor to
+.Fn malloc ,
+.Fn alloc ,
+first appeared in
+.At v1 .
+The C Library functions
+.Fn alloc
+and
+.Fn free
+appeared in
+.At v6 .
+The functions
+.Fn malloc ,
+.Fn calloc ,
+and
+.Fn realloc
+first appeared in
+.At v7 .
+.Pp
+A new implementation by Chris Kingsley was introduced in
+.Bx 4.2 ,
+followed by a complete rewrite by Poul-Henning Kamp (
+.Dq phk's malloc
+or
+.Dq new malloc )
+which appeared in
+.Fx 2.2
+and was included in
+.Nx  1.5
+and
+.Ox 2.0 .
+These implementations were all
+.Xr sbrk 2
+based.
+.Pp
+The
+.Fn jemalloc 3
+allocator became the default system allocator first in
+.Fx 7.0
+and then in
+.Nx 5.0 .