NAME¶
malloc_trim - release free memory from the top of the heap
SYNOPSIS¶
#include <malloc.h>
int malloc_trim(size_t pad);
DESCRIPTION¶
The
malloc_trim() function attempts to release free memory at the top of
the heap (by calling
sbrk(2) with a suitable argument).
The
pad argument specifies the amount of free space to leave untrimmed at
the top of the heap. If this argument is 0, only the minimum amount of memory
is maintained at the top of the heap (i.e., one page or less). A nonzero
argument can be used to maintain some trailing space at the top of the heap in
order to allow future allocations to be made without having to extend the heap
with
sbrk(2).
RETURN VALUE¶
The
malloc_trim() function returns 1 if memory was actually released back
to the system, or 0 if it was not possible to release any memory.
ERRORS¶
No errors are defined.
This function is a GNU extension.
NOTES¶
This function is automatically called by
free(3) in certain
circumstances; see the discussion of
M_TOP_PAD and
M_TRIM_THRESHOLD in
mallopt(3).
This function cannot release free memory located at places other than the top of
the heap.
This function releases only memory in the main arena.
SEE ALSO¶
sbrk(2),
malloc(3),
mallopt(3)
COLOPHON¶
This page is part of release 3.74 of the Linux
man-pages project. A
description of the project, information about reporting bugs, and the latest
version of this page, can be found at
http://www.kernel.org/doc/man-pages/.
