#define JEMALLOC_CHUNK_C_ #include "jemalloc/internal/jemalloc_internal.h" /******************************************************************************/ /* Data. */ const char *opt_dss = DSS_DEFAULT; size_t opt_lg_chunk = LG_CHUNK_DEFAULT; /* Used exclusively for gdump triggering. */ static size_t curchunks; static size_t highchunks; rtree_t chunks_rtree; /* Various chunk-related settings. */ size_t chunksize; size_t chunksize_mask; /* (chunksize - 1). */ size_t chunk_npages; /******************************************************************************/ bool chunk_register(const void *chunk, const extent_node_t *node) { assert(extent_node_addr_get(node) == chunk); if (rtree_set(&chunks_rtree, (uintptr_t)chunk, node)) return (true); if (config_prof && opt_prof) { size_t size = extent_node_size_get(node); size_t nadd = (size == 0) ? 1 : size / chunksize; size_t cur = atomic_add_z(&curchunks, nadd); size_t high = atomic_read_z(&highchunks); while (cur > high && atomic_cas_z(&highchunks, high, cur)) { /* * Don't refresh cur, because it may have decreased * since this thread lost the highchunks update race. */ high = atomic_read_z(&highchunks); } if (cur > high && prof_gdump_get_unlocked()) prof_gdump(); } return (false); } void chunk_deregister(const void *chunk, const extent_node_t *node) { bool err; err = rtree_set(&chunks_rtree, (uintptr_t)chunk, NULL); assert(!err); if (config_prof && opt_prof) { size_t size = extent_node_size_get(node); size_t nsub = (size == 0) ? 1 : size / chunksize; assert(atomic_read_z(&curchunks) >= nsub); atomic_sub_z(&curchunks, nsub); } } static void * chunk_recycle(arena_t *arena, extent_tree_t *chunks_szad, extent_tree_t *chunks_ad, bool dirty, void *new_addr, size_t size, size_t alignment, bool *zero) { void *ret; extent_node_t *node; extent_node_t key; size_t alloc_size, leadsize, trailsize; bool zeroed; assert(new_addr == NULL || alignment == chunksize); alloc_size = size + alignment - chunksize; /* Beware size_t wrap-around. */ if (alloc_size < size) return (NULL); extent_node_addr_set(&key, new_addr); extent_node_size_set(&key, alloc_size); malloc_mutex_lock(&arena->chunks_mtx); node = (new_addr != NULL) ? extent_tree_ad_search(chunks_ad, &key) : extent_tree_szad_nsearch(chunks_szad, &key); if (node == NULL || (new_addr != NULL && extent_node_size_get(node) < size)) { malloc_mutex_unlock(&arena->chunks_mtx); return (NULL); } leadsize = ALIGNMENT_CEILING((uintptr_t)extent_node_addr_get(node), alignment) - (uintptr_t)extent_node_addr_get(node); assert(new_addr == NULL || leadsize == 0); assert(extent_node_size_get(node) >= leadsize + size); trailsize = extent_node_size_get(node) - leadsize - size; ret = (void *)((uintptr_t)extent_node_addr_get(node) + leadsize); zeroed = extent_node_zeroed_get(node); if (zeroed) *zero = true; /* Remove node from the tree. */ extent_tree_szad_remove(chunks_szad, node); extent_tree_ad_remove(chunks_ad, node); arena_chunk_dirty_maybe_remove(arena, node, dirty); if (leadsize != 0) { /* Insert the leading space as a smaller chunk. */ extent_node_size_set(node, leadsize); extent_tree_szad_insert(chunks_szad, node); extent_tree_ad_insert(chunks_ad, node); arena_chunk_dirty_maybe_insert(arena, node, dirty); node = NULL; } if (trailsize != 0) { /* Insert the trailing space as a smaller chunk. */ if (node == NULL) { node = arena_node_alloc(arena); if (node == NULL) { malloc_mutex_unlock(&arena->chunks_mtx); chunk_record(arena, chunks_szad, chunks_ad, dirty, ret, size); return (NULL); } } extent_node_addr_set(node, (void *)((uintptr_t)(ret) + size)); extent_node_size_set(node, trailsize); extent_node_zeroed_set(node, zeroed); extent_tree_szad_insert(chunks_szad, node); extent_tree_ad_insert(chunks_ad, node); arena_chunk_dirty_maybe_insert(arena, node, dirty); node = NULL; } malloc_mutex_unlock(&arena->chunks_mtx); if (node != NULL) arena_node_dalloc(arena, node); if (*zero) { if (!zeroed) memset(ret, 0, size); else if (config_debug) { size_t i; size_t *p = (size_t *)(uintptr_t)ret; JEMALLOC_VALGRIND_MAKE_MEM_DEFINED(ret, size); for (i = 0; i < size / sizeof(size_t); i++) assert(p[i] == 0); } } return (ret); } static void * chunk_alloc_core_dss(arena_t *arena, void *new_addr, size_t size, size_t alignment, bool *zero) { void *ret; if ((ret = chunk_recycle(arena, &arena->chunks_szad_dss, &arena->chunks_ad_dss, false, new_addr, size, alignment, zero)) != NULL) return (ret); ret = chunk_alloc_dss(arena, new_addr, size, alignment, zero); return (ret); } /* * If the caller specifies (!*zero), it is still possible to receive zeroed * memory, in which case *zero is toggled to true. arena_chunk_alloc() takes * advantage of this to avoid demanding zeroed chunks, but taking advantage of * them if they are returned. */ static void * chunk_alloc_core(arena_t *arena, void *new_addr, size_t size, size_t alignment, bool *zero, dss_prec_t dss_prec) { void *ret; assert(size != 0); assert((size & chunksize_mask) == 0); assert(alignment != 0); assert((alignment & chunksize_mask) == 0); /* dirty. */ if ((ret = chunk_recycle(arena, &arena->chunks_szad_dirty, &arena->chunks_ad_dirty, true, new_addr, size, alignment, zero)) != NULL) return (ret); /* "primary" dss. */ if (have_dss && dss_prec == dss_prec_primary && (ret = chunk_alloc_core_dss(arena, new_addr, size, alignment, zero)) != NULL) return (ret); /* mmap. */ if (!config_munmap && (ret = chunk_recycle(arena, &arena->chunks_szad_mmap, &arena->chunks_ad_mmap, false, new_addr, size, alignment, zero)) != NULL) return (ret); /* * Requesting an address is not implemented for chunk_alloc_mmap(), so * only call it if (new_addr == NULL). */ if (new_addr == NULL && (ret = chunk_alloc_mmap(size, alignment, zero)) != NULL) return (ret); /* "secondary" dss. */ if (have_dss && dss_prec == dss_prec_secondary && (ret = chunk_alloc_core_dss(arena, new_addr, size, alignment, zero)) != NULL) return (ret); /* All strategies for allocation failed. */ return (NULL); } void * chunk_alloc_base(size_t size) { void *ret; bool zero; /* * Directly call chunk_alloc_mmap() rather than chunk_alloc_core() * because it's critical that chunk_alloc_base() return untouched * demand-zeroed virtual memory. */ zero = true; ret = chunk_alloc_mmap(size, chunksize, &zero); if (ret == NULL) return (NULL); if (config_valgrind) JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size); return (ret); } void * chunk_alloc_arena(chunk_alloc_t *chunk_alloc, chunk_dalloc_t *chunk_dalloc, unsigned arena_ind, void *new_addr, size_t size, size_t alignment, bool *zero) { void *ret; ret = chunk_alloc(new_addr, size, alignment, zero, arena_ind); if (ret == NULL) return (NULL); if (config_valgrind) JEMALLOC_VALGRIND_MAKE_MEM_UNDEFINED(ret, size); return (ret); } static arena_t * chunk_arena_get(unsigned arena_ind) { arena_t *arena; /* Dodge tsd for a0 in order to avoid bootstrapping issues. */ arena = (arena_ind == 0) ? a0get() : arena_get(tsd_fetch(), arena_ind, false, true); /* * The arena we're allocating on behalf of must have been initialized * already. */ assert(arena != NULL); return (arena); } /* Default arena chunk allocation routine in the absence of user override. */ void * chunk_alloc_default(void *new_addr, size_t size, size_t alignment, bool *zero, unsigned arena_ind) { arena_t *arena; arena = chunk_arena_get(arena_ind); return (chunk_alloc_core(arena, new_addr, size, alignment, zero, arena->dss_prec)); } void chunk_record(arena_t *arena, extent_tree_t *chunks_szad, extent_tree_t *chunks_ad, bool dirty, void *chunk, size_t size) { bool unzeroed; extent_node_t *node, *prev; extent_node_t key; unzeroed = dirty ? true : pages_purge(chunk, size); JEMALLOC_VALGRIND_MAKE_MEM_NOACCESS(chunk, size); malloc_mutex_lock(&arena->chunks_mtx); extent_node_addr_set(&key, (void *)((uintptr_t)chunk + size)); node = extent_tree_ad_nsearch(chunks_ad, &key); /* Try to coalesce forward. */ if (node != NULL && extent_node_addr_get(node) == extent_node_addr_get(&key)) { /* * Coalesce chunk with the following address range. This does * not change the position within chunks_ad, so only * remove/insert from/into chunks_szad. */ extent_tree_szad_remove(chunks_szad, node); arena_chunk_dirty_maybe_remove(arena, node, dirty); extent_node_addr_set(node, chunk); extent_node_size_set(node, extent_node_size_get(node) + size); extent_node_zeroed_set(node, extent_node_zeroed_get(node) && !unzeroed); extent_tree_szad_insert(chunks_szad, node); arena_chunk_dirty_maybe_insert(arena, node, dirty); } else { /* Coalescing forward failed, so insert a new node. */ node = arena_node_alloc(arena); if (node == NULL) { /* * Node allocation failed, which is an exceedingly * unlikely failure. Leak chunk after making sure its * pages have already been purged, so that this is only * a virtual memory leak. */ if (dirty) pages_purge(chunk, size); goto label_return; } extent_node_addr_set(node, chunk); extent_node_size_set(node, size); extent_node_zeroed_set(node, !unzeroed); extent_tree_ad_insert(chunks_ad, node); extent_tree_szad_insert(chunks_szad, node); arena_chunk_dirty_maybe_insert(arena, node, dirty); } /* Try to coalesce backward. */ prev = extent_tree_ad_prev(chunks_ad, node); if (prev != NULL && (void *)((uintptr_t)extent_node_addr_get(prev) + extent_node_size_get(prev)) == chunk) { /* * Coalesce chunk with the previous address range. This does * not change the position within chunks_ad, so only * remove/insert node from/into chunks_szad. */ extent_tree_szad_remove(chunks_szad, prev); extent_tree_ad_remove(chunks_ad, prev); arena_chunk_dirty_maybe_remove(arena, prev, dirty); extent_tree_szad_remove(chunks_szad, node); arena_chunk_dirty_maybe_remove(arena, node, dirty); extent_node_addr_set(node, extent_node_addr_get(prev)); extent_node_size_set(node, extent_node_size_get(node) + extent_node_size_get(prev)); extent_node_zeroed_set(node, extent_node_zeroed_get(node) && extent_node_zeroed_get(prev)); extent_tree_szad_insert(chunks_szad, node); arena_chunk_dirty_maybe_insert(arena, node, dirty); arena_node_dalloc(arena, prev); } label_return: malloc_mutex_unlock(&arena->chunks_mtx); } static void chunk_cache(arena_t *arena, void *chunk, size_t size) { assert(chunk != NULL); assert(CHUNK_ADDR2BASE(chunk) == chunk); assert(size != 0); assert((size & chunksize_mask) == 0); chunk_record(arena, &arena->chunks_szad_dirty, &arena->chunks_ad_dirty, true, chunk, size); } /* Default arena chunk deallocation routine in the absence of user override. */ bool chunk_dalloc_default(void *chunk, size_t size, unsigned arena_ind) { chunk_cache(chunk_arena_get(arena_ind), chunk, size); return (false); } void chunk_unmap(arena_t *arena, void *chunk, size_t size) { assert(chunk != NULL); assert(CHUNK_ADDR2BASE(chunk) == chunk); assert(size != 0); assert((size & chunksize_mask) == 0); if (have_dss && chunk_in_dss(chunk)) { chunk_record(arena, &arena->chunks_szad_dss, &arena->chunks_ad_dss, false, chunk, size); } else if (chunk_dalloc_mmap(chunk, size)) { chunk_record(arena, &arena->chunks_szad_mmap, &arena->chunks_ad_mmap, false, chunk, size); } } static rtree_node_elm_t * chunks_rtree_node_alloc(size_t nelms) { return ((rtree_node_elm_t *)base_alloc(nelms * sizeof(rtree_node_elm_t))); } bool chunk_boot(void) { /* Set variables according to the value of opt_lg_chunk. */ chunksize = (ZU(1) << opt_lg_chunk); assert(chunksize >= PAGE); chunksize_mask = chunksize - 1; chunk_npages = (chunksize >> LG_PAGE); if (have_dss && chunk_dss_boot()) return (true); if (rtree_new(&chunks_rtree, (ZU(1) << (LG_SIZEOF_PTR+3)) - opt_lg_chunk, chunks_rtree_node_alloc, NULL)) return (true); return (false); } void chunk_prefork(void) { chunk_dss_prefork(); } void chunk_postfork_parent(void) { chunk_dss_postfork_parent(); } void chunk_postfork_child(void) { chunk_dss_postfork_child(); }