malloc_trim(3)

1MALLOC_TRIM(3)             Linux Programmer's Manual            MALLOC_TRIM(3)
2
3
4

NAME

6       malloc_trim - release free memory from the top of the heap
7

SYNOPSIS

9       #include <malloc.h>
10
11       void malloc_trim(size_t pad);
12

DESCRIPTION

14       The  malloc_trim()  function attempts to release free memory at the top
15       of the heap (by calling sbrk(2) with a suitable argument).
16
17       The pad argument specifies the amount of free space to leave  untrimmed
18       at the top of the heap.  If this argument is 0, only the minimum amount
19       of memory is maintained at the top of  the  heap  (i.e.,  one  page  or
20       less).   A nonzero argument can be used to maintain some trailing space
21       at the top of the heap in order to allow future allocations to be  made
22       without having to extend the heap with sbrk(2).
23

RETURN VALUE

25       The  malloc_trim()  function  returns 1 if memory was actually released
26       back to the system, or 0 if it was not possible to release any memory.
27

ERRORS

29       No errors are defined.
30

CONFORMING TO

32       This function is a GNU extension.
33

NOTES

35       This function is automatically called by  free(3)  in  certain  circum‐
36       stances;  see  the discussion of M_TOP_PAD and M_TRIM_THRESHOLD in mal‐
37       lopt(3).
38
39       This function cannot release free memory located at places  other  than
40       the top of the heap.
41
42       This function releases only memory in the main arena.
43

COLOPHON

48       This  page  is  part of release 3.53 of the Linux man-pages project.  A
49       description of the project, and information about reporting  bugs,  can
50       be found at http://www.kernel.org/doc/man-pages/.
51
52
53
54Linux                             2012-03-29                    MALLOC_TRIM(3)