diff options
Diffstat (limited to 'Objects/obmalloc.c')
| -rw-r--r-- | Objects/obmalloc.c | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c index 3916262120..9a7c7e7ce6 100644 --- a/Objects/obmalloc.c +++ b/Objects/obmalloc.c @@ -2,6 +2,10 @@ #ifdef WITH_PYMALLOC +#ifdef HAVE_MALLOPT_MMAP_THRESHOLD + #include <malloc.h> +#endif + #ifdef WITH_VALGRIND #include <valgrind/valgrind.h> @@ -75,7 +79,8 @@ static int running_on_valgrind = -1; * Allocation strategy abstract: * * For small requests, the allocator sub-allocates <Big> blocks of memory. - * Requests greater than 256 bytes are routed to the system's allocator. + * Requests greater than SMALL_REQUEST_THRESHOLD bytes are routed to the + * system's allocator. * * Small requests are grouped in size classes spaced 8 bytes apart, due * to the required valid alignment of the returned address. Requests of @@ -107,10 +112,11 @@ static int running_on_valgrind = -1; * 57-64 64 7 * 65-72 72 8 * ... ... ... - * 241-248 248 30 - * 249-256 256 31 + * 497-504 504 62 + * 505-512 512 63 * - * 0, 257 and up: routed to the underlying allocator. + * 0, SMALL_REQUEST_THRESHOLD + 1 and up: routed to the underlying + * allocator. */ /*==========================================================================*/ @@ -139,14 +145,17 @@ static int running_on_valgrind = -1; * small enough in order to use preallocated memory pools. You can tune * this value according to your application behaviour and memory needs. * + * Note: a size threshold of 512 guarantees that newly created dictionaries + * will be allocated from preallocated memory pools on 64-bit. + * * The following invariants must hold: - * 1) ALIGNMENT <= SMALL_REQUEST_THRESHOLD <= 256 + * 1) ALIGNMENT <= SMALL_REQUEST_THRESHOLD <= 512 * 2) SMALL_REQUEST_THRESHOLD is evenly divisible by ALIGNMENT * * Although not required, for better performance and space efficiency, * it is recommended that SMALL_REQUEST_THRESHOLD is set to a power of 2. */ -#define SMALL_REQUEST_THRESHOLD 256 +#define SMALL_REQUEST_THRESHOLD 512 #define NB_SMALL_SIZE_CLASSES (SMALL_REQUEST_THRESHOLD / ALIGNMENT) /* @@ -440,6 +449,9 @@ static poolp usedpools[2 * ((NB_SMALL_SIZE_CLASSES + 7) / 8) * 8] = { , PT(48), PT(49), PT(50), PT(51), PT(52), PT(53), PT(54), PT(55) #if NB_SMALL_SIZE_CLASSES > 56 , PT(56), PT(57), PT(58), PT(59), PT(60), PT(61), PT(62), PT(63) +#if NB_SMALL_SIZE_CLASSES > 64 +#error "NB_SMALL_SIZE_CLASSES should be less than 64" +#endif /* NB_SMALL_SIZE_CLASSES > 64 */ #endif /* NB_SMALL_SIZE_CLASSES > 56 */ #endif /* NB_SMALL_SIZE_CLASSES > 48 */ #endif /* NB_SMALL_SIZE_CLASSES > 40 */ @@ -545,6 +557,11 @@ new_arena(void) if (numarenas > PY_SIZE_MAX / sizeof(*arenas)) return NULL; /* overflow */ #endif +#ifdef HAVE_MALLOPT_MMAP_THRESHOLD + /* Ensure arenas are allocated by mmap to avoid heap fragmentation. */ + if (numarenas == INITIAL_ARENA_OBJECTS) + mallopt(M_MMAP_THRESHOLD, ARENA_SIZE); +#endif nbytes = numarenas * sizeof(*arenas); arenaobj = (struct arena_object *)realloc(arenas, nbytes); if (arenaobj == NULL) @@ -1775,7 +1792,6 @@ _PyObject_DebugMallocStats(void) * will be living in full pools -- would be a shame to miss them. */ for (i = 0; i < maxarenas; ++i) { - uint poolsinarena; uint j; uptr base = arenas[i].address; @@ -1784,7 +1800,6 @@ _PyObject_DebugMallocStats(void) continue; narenas += 1; - poolsinarena = arenas[i].ntotalpools; numfreepools += arenas[i].nfreepools; /* round up to pool alignment */ |