1 /* Malloc huge page support.  Generic implementation.
2    Copyright (C) 2021-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public License as
7    published by the Free Software Foundation; either version 2.1 of the
8    License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; see the file COPYING.LIB.  If
17    not, see <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef _MALLOC_HUGEPAGES_H
20 #define _MALLOC_HUGEPAGES_H
21 
22 #include <stddef.h>
23 
24 /* Return the default transparent huge page size.  */
25 unsigned long int __malloc_default_thp_pagesize (void) attribute_hidden;
26 
27 enum malloc_thp_mode_t
28 {
29   malloc_thp_mode_always,
30   malloc_thp_mode_madvise,
31   malloc_thp_mode_never,
32   malloc_thp_mode_not_supported
33 };
34 
35 enum malloc_thp_mode_t __malloc_thp_mode (void) attribute_hidden;
36 
37 /* Return the supported huge page size from the REQUESTED sizes on PAGESIZE
38    along with the required extra mmap flags on FLAGS,  Requesting the value
39    of 0 returns the default huge page size, otherwise the value will be
40    matched against the sizes supported by the system.  */
41 void __malloc_hugepage_config (size_t requested, size_t *pagesize, int *flags)
42      attribute_hidden;
43 
44 #endif /* _MALLOC_HUGEPAGES_H */
45