[PATCH] Remove references to sbrk to grow/shrink arenas

[DJ Delorie]

Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> 	* manual/memory.texi (M_TOP_PAD): Remove reference to sbrk.
> 	(M_TRIM_THRESHOLD): Likewise.

These changes look good to me from the malloc side of things.