NAME
malloctrim - release free memory from the top of the heap SYNOPSIS
#include
void malloctrim(sizet pad); DESCRIPTION The malloctrim() 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 malloctrim() 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. CONFORMING TO This function is a GNU extension. NOTES This function is automatically called by free(3) in certain circum‐ stances; see the discussion of MTOPPAD and MTRIMTHRESHOLD in mal‐ lopt(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 3.53 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 MALLOCTRIM(3)