diff options
| -rw-r--r-- | man3/malloc_trim.3 | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/man3/malloc_trim.3 b/man3/malloc_trim.3 index 3ff8bd0ee3..dd73fe631f 100644 --- a/man3/malloc_trim.3 +++ b/man3/malloc_trim.3 @@ -25,7 +25,7 @@ .\" .TH MALLOC_TRIM 3 2017-09-15 "Linux" "Linux Programmer's Manual" .SH NAME -malloc_trim \- release free memory from the top of the heap +malloc_trim \- release free memory from the heap .SH SYNOPSIS .B #include <malloc.h> .PP @@ -33,10 +33,12 @@ malloc_trim \- release free memory from the top of the heap .SH DESCRIPTION The .BR malloc_trim () -function attempts to release free memory at the top of the heap +function attempts to release free memory from the heap (by calling .BR sbrk (2) -with a suitable argument). +or +.BR madvise (2) +with suitable arguments). .PP The .I pad @@ -82,12 +84,18 @@ and in .BR mallopt (3). .PP -This function cannot release free memory located at places -other than the top of the heap. +Only the main heap (using +.BR sbrk (2) +) honors the pad argument; thread heaps do not. +.PP +Since glibc 2.8 this function frees memory in all arenas and in all +chunks with whole free pages. +.\" See commit 68631c8eb92ff38d9da1ae34f6aa048539b199cc +.\" (dated 2007-12-16) which adds iteration over all +.\" arenas and frees all pages in chunks which are free. .PP -This function releases only memory in the main arena. -.\" malloc/malloc.c::mTRIm(): -.\" return result | (av == &main_arena ? sYSTRIm (pad, av) : 0); +Before glibc 2.8 this function only freed memory at the +top of the heap in the main arena. .SH SEE ALSO .BR sbrk (2), .BR malloc (3), |