MALLOC_TRIM(3) Linux Programmer's Manual MALLOC_TRIM(3)NAME
malloc_trim - release free memory from the top of the heap
void malloc_trim(size_t pad);
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).
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.
No errors are defined.
This function is a GNU extension.
This function is automatically called by free(3) in certain circum‐
stances; see the discussion of M_TOP_PAD and M_TRIM_THRESHOLD in mal‐
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 ALSOsbrk(2), malloc(3), mallopt(3)COLOPHON
This page is part of release 3.65 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2012-03-29 MALLOC_TRIM(3)