1 #ifndef JEMALLOC_INTERNAL_BASE_TYPES_H
2 #define JEMALLOC_INTERNAL_BASE_TYPES_H
3 
4 typedef struct base_block_s base_block_t;
5 typedef struct base_s base_t;
6 
7 #define METADATA_THP_DEFAULT metadata_thp_disabled
8 
9 /*
10  * In auto mode, arenas switch to huge pages for the base allocator on the
11  * second base block.  a0 switches to thp on the 5th block (after 20 megabytes
12  * of metadata), since more metadata (e.g. rtree nodes) come from a0's base.
13  */
14 
15 #define BASE_AUTO_THP_THRESHOLD    2
16 #define BASE_AUTO_THP_THRESHOLD_A0 5
17 
18 typedef enum {
19 	metadata_thp_disabled   = 0,
20 	/*
21 	 * Lazily enable hugepage for metadata. To avoid high RSS caused by THP
22 	 * + low usage arena (i.e. THP becomes a significant percentage), the
23 	 * "auto" option only starts using THP after a base allocator used up
24 	 * the first THP region.  Starting from the second hugepage (in a single
25 	 * arena), "auto" behaves the same as "always", i.e. madvise hugepage
26 	 * right away.
27 	 */
28 	metadata_thp_auto       = 1,
29 	metadata_thp_always     = 2,
30 	metadata_thp_mode_limit = 3
31 } metadata_thp_mode_t;
32 
33 #endif /* JEMALLOC_INTERNAL_BASE_TYPES_H */
34