1 #define JEMALLOC_CHUNK_MMAP_C_
2 #include "jemalloc/internal/jemalloc_internal.h"
4 /******************************************************************************/
7 chunk_alloc_mmap_slow(size_t size, size_t alignment, bool *zero, bool *commit)
12 alloc_size = size + alignment - PAGE;
13 /* Beware size_t wrap-around. */
14 if (alloc_size < size)
19 pages = pages_map(NULL, alloc_size, commit);
22 leadsize = ALIGNMENT_CEILING((uintptr_t)pages, alignment) -
24 ret = pages_trim(pages, alloc_size, leadsize, size, commit);
25 } while (ret == NULL);
33 chunk_alloc_mmap(void *new_addr, size_t size, size_t alignment, bool *zero,
40 * Ideally, there would be a way to specify alignment to mmap() (like
41 * NetBSD has), but in the absence of such a feature, we have to work
42 * hard to efficiently create aligned mappings. The reliable, but
43 * slow method is to create a mapping that is over-sized, then trim the
44 * excess. However, that always results in one or two calls to
47 * Optimistically try mapping precisely the right amount before falling
48 * back to the slow method, with the expectation that the optimistic
49 * approach works most of the time.
52 assert(alignment != 0);
53 assert((alignment & chunksize_mask) == 0);
55 ret = pages_map(new_addr, size, commit);
56 if (ret == NULL || ret == new_addr)
58 assert(new_addr == NULL);
59 offset = ALIGNMENT_ADDR2OFFSET(ret, alignment);
61 pages_unmap(ret, size);
62 return (chunk_alloc_mmap_slow(size, alignment, zero, commit));
71 chunk_dalloc_mmap(void *chunk, size_t size)
75 pages_unmap(chunk, size);
77 return (!config_munmap);