diff options
| -rw-r--r-- | include/jemalloc/internal/base_structs.h | 9 | ||||
| -rw-r--r-- | src/base.c | 62 |
2 files changed, 44 insertions, 27 deletions
diff --git a/include/jemalloc/internal/base_structs.h b/include/jemalloc/internal/base_structs.h index 13d5bd4..d79f38e 100644 --- a/include/jemalloc/internal/base_structs.h +++ b/include/jemalloc/internal/base_structs.h @@ -21,11 +21,18 @@ struct base_s { * User-configurable extent hook functions. Points to an * extent_hooks_t. */ - atomic_p_t extent_hooks; + atomic_p_t extent_hooks; /* Protects base_alloc() and base_stats_get() operations. */ malloc_mutex_t mtx; + /* + * Most recent size class in the series of increasingly large base + * extents. Logarithmic spacing between subsequent allocations ensures + * that the total number of distinct mappings remains small. + */ + pszind_t pind_last; + /* Serial number generation state. */ size_t extent_sn_next; @@ -155,19 +155,33 @@ base_extent_bump_alloc(tsdn_t *tsdn, base_t *base, extent_t *extent, */ static base_block_t * base_block_alloc(extent_hooks_t *extent_hooks, unsigned ind, - size_t *extent_sn_next, size_t size, size_t alignment) { - base_block_t *block; - size_t usize, header_size, gap_size, block_size; - + pszind_t *pind_last, size_t *extent_sn_next, size_t size, + size_t alignment) { alignment = ALIGNMENT_CEILING(alignment, QUANTUM); - usize = ALIGNMENT_CEILING(size, alignment); - header_size = sizeof(base_block_t); - gap_size = ALIGNMENT_CEILING(header_size, alignment) - header_size; - block_size = HUGEPAGE_CEILING(header_size + gap_size + usize); - block = (base_block_t *)base_map(extent_hooks, ind, block_size); + size_t usize = ALIGNMENT_CEILING(size, alignment); + size_t header_size = sizeof(base_block_t); + size_t gap_size = ALIGNMENT_CEILING(header_size, alignment) - + header_size; + /* + * Create increasingly larger blocks in order to limit the total number + * of disjoint virtual memory ranges. Choose the next size in the page + * size class series (skipping size classes that are not a multiple of + * HUGEPAGE), or a size large enough to satisfy the requested size and + * alignment, whichever is larger. + */ + size_t min_block_size = HUGEPAGE_CEILING(psz2u(header_size + gap_size + + usize)); + pszind_t pind_next = (*pind_last + 1 < NPSIZES) ? *pind_last + 1 : + *pind_last; + size_t next_block_size = HUGEPAGE_CEILING(pind2sz(pind_next)); + size_t block_size = (min_block_size > next_block_size) ? min_block_size + : next_block_size; + base_block_t *block = (base_block_t *)base_map(extent_hooks, ind, + block_size); if (block == NULL) { return NULL; } + *pind_last = psz2ind(block_size); block->size = block_size; block->next = NULL; assert(block_size >= header_size); @@ -182,13 +196,11 @@ base_block_alloc(extent_hooks_t *extent_hooks, unsigned ind, */ static extent_t * base_extent_alloc(tsdn_t *tsdn, base_t *base, size_t size, size_t alignment) { - extent_hooks_t *extent_hooks = base_extent_hooks_get(base); - base_block_t *block; - malloc_mutex_assert_owner(tsdn, &base->mtx); - block = base_block_alloc(extent_hooks, base_ind_get(base), - &base->extent_sn_next, size, alignment); + extent_hooks_t *extent_hooks = base_extent_hooks_get(base); + base_block_t *block = base_block_alloc(extent_hooks, base_ind_get(base), + &base->pind_last, &base->extent_sn_next, size, alignment); if (block == NULL) { return NULL; } @@ -211,21 +223,18 @@ b0get(void) { base_t * base_new(tsdn_t *tsdn, unsigned ind, extent_hooks_t *extent_hooks) { - base_t *base; - size_t extent_sn_next, base_alignment, base_size, gap_size; - base_block_t *block; - szind_t i; - - extent_sn_next = 0; - block = base_block_alloc(extent_hooks, ind, &extent_sn_next, - sizeof(base_t), QUANTUM); + pszind_t pind_last = 0; + size_t extent_sn_next = 0; + base_block_t *block = base_block_alloc(extent_hooks, ind, &pind_last, + &extent_sn_next, sizeof(base_t), QUANTUM); if (block == NULL) { return NULL; } - base_alignment = CACHELINE; - base_size = ALIGNMENT_CEILING(sizeof(base_t), base_alignment); - base = (base_t *)base_extent_bump_alloc_helper(&block->extent, + size_t gap_size; + size_t base_alignment = CACHELINE; + size_t base_size = ALIGNMENT_CEILING(sizeof(base_t), base_alignment); + base_t *base = (base_t *)base_extent_bump_alloc_helper(&block->extent, &gap_size, base_size, base_alignment); base->ind = ind; atomic_store_p(&base->extent_hooks, extent_hooks, ATOMIC_RELAXED); @@ -233,9 +242,10 @@ base_new(tsdn_t *tsdn, unsigned ind, extent_hooks_t *extent_hooks) { base_unmap(extent_hooks, ind, block, block->size); return NULL; } + base->pind_last = pind_last; base->extent_sn_next = extent_sn_next; base->blocks = block; - for (i = 0; i < NSIZES; i++) { + for (szind_t i = 0; i < NSIZES; i++) { extent_heap_new(&base->avail[i]); } if (config_stats) { |