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--- libmalloc/libmalloc-657.60.21/src/magazine_small.c
+++ libmalloc/libmalloc-283.60.1/src/magazine_small.c
@@ -66,6 +66,25 @@
meta_headers[index] = 0;
}
+static MALLOC_INLINE MALLOC_ALWAYS_INLINE
+mag_index_t
+small_mag_get_thread_index(void)
+{
+#if CONFIG_SMALL_USES_HYPER_SHIFT
+ if (os_likely(_os_cpu_number_override == -1)) {
+ return _os_cpu_number() >> hyper_shift;
+ } else {
+ return _os_cpu_number_override >> hyper_shift;
+ }
+#else // CONFIG_SMALL_USES_HYPER_SHIFT
+ if (os_likely(_os_cpu_number_override == -1)) {
+ return _os_cpu_number();
+ } else {
+ return _os_cpu_number_override;
+ }
+#endif // CONFIG_SMALL_USES_HYPER_SHIFT
+}
+
#pragma mark in-place free list
static MALLOC_INLINE void
@@ -241,7 +260,7 @@
static MALLOC_INLINE void
small_oob_free_entry_set_ptr(oob_free_entry_t oobe, void *ptr)
{
- oobe->ptr = SMALL_IS_OOB | (SMALL_REGION_OFFSET_FOR_PTR(ptr) >> SHIFT_SMALL_QUANTUM);
+ oobe->ptr = SMALL_IS_OOB | (SMALL_OFFSET_FOR_PTR(ptr) >> SHIFT_SMALL_QUANTUM);
}
static MALLOC_INLINE void
@@ -637,7 +656,7 @@
// than performing this workaround.
//
if (small_mag_ptr->mag_bytes_free_at_end) {
- last_block = SMALL_REGION_HEAP_END(small_mag_ptr->mag_last_region) - small_mag_ptr->mag_bytes_free_at_end;
+ last_block = SMALL_REGION_END(small_mag_ptr->mag_last_region) - small_mag_ptr->mag_bytes_free_at_end;
last_msize = SMALL_MSIZE_FOR_BYTES(small_mag_ptr->mag_bytes_free_at_end);
last_index = SMALL_META_INDEX_FOR_PTR(last_block);
@@ -663,7 +682,7 @@
free_list_t next;
if (small_mag_ptr->mag_bytes_free_at_start) {
- last_block = SMALL_REGION_HEAP_BASE(small_mag_ptr->mag_last_region);
+ last_block = SMALL_REGION_ADDRESS(small_mag_ptr->mag_last_region);
last_msize = SMALL_MSIZE_FOR_BYTES(small_mag_ptr->mag_bytes_free_at_start);
void *next_block = (void *)((uintptr_t)last_block + small_mag_ptr->mag_bytes_free_at_start);
@@ -687,11 +706,12 @@
int
small_free_detach_region(rack_t *rack, magazine_t *small_mag_ptr, region_t r)
{
- uintptr_t start = (uintptr_t)SMALL_REGION_HEAP_BASE(r);
+ unsigned char *ptr = SMALL_REGION_ADDRESS(r);
+ msize_t *meta_headers = SMALL_META_HEADER_FOR_PTR(ptr);
+ uintptr_t start = (uintptr_t)SMALL_REGION_ADDRESS(r);
uintptr_t current = start;
- uintptr_t limit = (uintptr_t)SMALL_REGION_HEAP_END(r);
+ uintptr_t limit = (uintptr_t)SMALL_REGION_END(r);
int total_alloc = 0;
- msize_t *meta_headers = SMALL_META_HEADER_FOR_PTR(start);
while (current < limit) {
unsigned index = SMALL_META_INDEX_FOR_PTR(current);
@@ -721,11 +741,12 @@
size_t
small_free_reattach_region(rack_t *rack, magazine_t *small_mag_ptr, region_t r)
{
- uintptr_t start = (uintptr_t)SMALL_REGION_HEAP_BASE(r);
+ unsigned char *ptr = SMALL_REGION_ADDRESS(r);
+ msize_t *meta_headers = SMALL_META_HEADER_FOR_PTR(ptr);
+ uintptr_t start = (uintptr_t)SMALL_REGION_ADDRESS(r);
uintptr_t current = start;
- uintptr_t limit = (uintptr_t)SMALL_REGION_HEAP_END(r);
+ uintptr_t limit = (uintptr_t)SMALL_REGION_END(r);
size_t total_alloc = 0;
- msize_t *meta_headers = SMALL_META_HEADER_FOR_PTR(start);
while (current < limit) {
unsigned index = SMALL_META_INDEX_FOR_PTR(current);
@@ -756,11 +777,11 @@
void
small_free_scan_madvise_free(rack_t *rack, magazine_t *depot_ptr, region_t r)
{
- uintptr_t start = (uintptr_t)SMALL_REGION_HEAP_BASE(r);
+ uintptr_t start = (uintptr_t)SMALL_REGION_ADDRESS(r);
uintptr_t current = start;
- uintptr_t limit = (uintptr_t)SMALL_REGION_HEAP_END(r);
+ uintptr_t limit = (uintptr_t)SMALL_REGION_END(r);
msize_t *meta_headers = SMALL_META_HEADER_FOR_PTR(start);
- small_pg_pair_t advisory[((SMALL_HEAP_SIZE + vm_kernel_page_size - 1) >> vm_kernel_page_shift) >>
+ small_pg_pair_t advisory[((SMALL_REGION_PAYLOAD_BYTES + vm_kernel_page_size - 1) >> vm_kernel_page_shift) >>
1]; // 4096bytes stack allocated
int advisories = 0;
@@ -800,7 +821,7 @@
uintptr_t pgHi = trunc_page_kernel(current + SMALL_BYTES_FOR_MSIZE(msize) - sizeof(msize_t));
if (pgLo < pgHi) {
- advisory[advisories].pnum = (pgLo - (uintptr_t)r) >> vm_kernel_page_shift;
+ advisory[advisories].pnum = (pgLo - start) >> vm_kernel_page_shift;
advisory[advisories].size = (pgHi - pgLo) >> vm_kernel_page_shift;
advisories++;
}
@@ -814,8 +835,8 @@
OSAtomicIncrement32Barrier(&(REGION_TRAILER_FOR_SMALL_REGION(r)->pinned_to_depot));
SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
for (i = 0; i < advisories; ++i) {
- uintptr_t addr = (advisory[i].pnum << vm_kernel_page_shift) + (uintptr_t)r;
- size_t size = advisory[i].size << vm_kernel_page_shift;
+ uintptr_t addr = (advisory[i].pnum << vm_page_quanta_shift) + start;
+ size_t size = advisory[i].size << vm_page_quanta_shift;
mvm_madvise_free(rack, r, addr, addr + size, NULL, rack->debug_flags & MALLOC_DO_SCRIBBLE);
}
@@ -897,6 +918,11 @@
{
magazine_t *depot_ptr = &(rack->magazines[DEPOT_MAGAZINE_INDEX]);
+ /* FIXME: Would Uniprocessor benefit from recirc and MADV_FREE? */
+ if (rack->num_magazines == 1) { // Uniprocessor, single magazine, so no recirculation necessary
+ return 0;
+ }
+
#if DEBUG_MALLOC
if (DEPOT_MAGAZINE_INDEX == mag_index) {
malloc_zone_error(rack->debug_flags, true, "small_get_region_from_depot called for magazine index -1\n", NULL, NULL);
@@ -909,32 +935,22 @@
// Appropriate a Depot'd region that can satisfy requested msize.
region_trailer_t *node;
region_t sparse_region;
- msize_t try_msize = msize;
while (1) {
- sparse_region = small_find_msize_region(rack, depot_ptr, DEPOT_MAGAZINE_INDEX, try_msize);
+ sparse_region = small_find_msize_region(rack, depot_ptr, DEPOT_MAGAZINE_INDEX, msize);
if (NULL == sparse_region) { // Depot empty?
SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
return 0;
}
node = REGION_TRAILER_FOR_SMALL_REGION(sparse_region);
- if (0 == node->pinned_to_depot) {
- // Found one!
+ if (0 >= node->pinned_to_depot) {
break;
}
- // Try the next msize up - maybe the head of its free list will be in
- // a region we can use. Once we get the region we'll still allocate the
- // original msize.
- try_msize++;
-
- if (try_msize > NUM_SMALL_SLOTS) {
- // Tried all the msizes but couldn't get a usable region. Let's
- // give up for now and we'll allocate a new region from the kernel.
- SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
- return 0;
- }
+ SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
+ yield();
+ SZONE_MAGAZINE_PTR_LOCK(depot_ptr);
}
// disconnect node from Depot
@@ -945,17 +961,17 @@
// Transfer ownership of the region
MAGAZINE_INDEX_FOR_SMALL_REGION(sparse_region) = mag_index;
- MALLOC_ASSERT(node->pinned_to_depot == 0);
+ node->pinned_to_depot = 0;
// Iterate the region putting its free entries on its new (locked) magazine's free list
size_t bytes_inplay = small_free_reattach_region(rack, small_mag_ptr, sparse_region);
depot_ptr->mag_num_bytes_in_objects -= bytes_inplay;
- depot_ptr->num_bytes_in_magazine -= SMALL_HEAP_SIZE;
+ depot_ptr->num_bytes_in_magazine -= SMALL_REGION_PAYLOAD_BYTES;
depot_ptr->mag_num_objects -= objects_in_use;
small_mag_ptr->mag_num_bytes_in_objects += bytes_inplay;
- small_mag_ptr->num_bytes_in_magazine += SMALL_HEAP_SIZE;
+ small_mag_ptr->num_bytes_in_magazine += SMALL_REGION_PAYLOAD_BYTES;
small_mag_ptr->mag_num_objects += objects_in_use;
// connect to magazine as last node
@@ -980,30 +996,18 @@
for (mag_index = 0; mag_index < rack->num_magazines; mag_index++) {
size_t index;
for (index = 0; index < rack->region_generation->num_regions_allocated; ++index) {
- rack_region_lock(rack);
+ SZONE_LOCK(SMALL_SZONE_FROM_RACK(rack));
region_t small = rack->region_generation->hashed_regions[index];
if (!small || small == HASHRING_REGION_DEALLOCATED) {
- rack_region_unlock(rack);
+ SZONE_UNLOCK(SMALL_SZONE_FROM_RACK(rack));
continue;
}
- region_trailer_t *trailer = REGION_TRAILER_FOR_SMALL_REGION(small);
- // Make sure that the owning magazine doesn't try and take this out
- // from under our feet.
- trailer->dispose_flags |= RACK_DISPOSE_DELAY;
- rack_region_unlock(rack);
-
magazine_t *mag_ptr = mag_lock_zine_for_region_trailer(rack->magazines,
- trailer, MAGAZINE_INDEX_FOR_SMALL_REGION(small));
-
- // If acquiring the region lock was enough to prevent the owning
- // magazine from deallocating the region, free it now so we don't
- // do wasted work.
- if (rack_region_maybe_dispose(rack, small, SMALL_REGION_SIZE, trailer)) {
- SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
- continue;
- }
+ REGION_TRAILER_FOR_SMALL_REGION(small),
+ MAGAZINE_INDEX_FOR_SMALL_REGION(small));
+ SZONE_UNLOCK(SMALL_SZONE_FROM_RACK(rack));
/* Ordering is important here, the magazine of a region may potentially change
* during mag_lock_zine_for_region_trailer, so src_mag_index must be taken
@@ -1017,11 +1021,6 @@
continue;
}
- if (REGION_TRAILER_FOR_SMALL_REGION(small)->pinned_to_depot > 0) {
- SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
- continue;
- }
-
if (small == mag_ptr->mag_last_region && (mag_ptr->mag_bytes_free_at_end || mag_ptr->mag_bytes_free_at_start)) {
small_finalize_region(rack, mag_ptr);
}
@@ -1036,20 +1035,20 @@
SZONE_MAGAZINE_PTR_LOCK(small_depot_ptr);
MAGAZINE_INDEX_FOR_SMALL_REGION(small) = DEPOT_MAGAZINE_INDEX;
- MALLOC_ASSERT(REGION_TRAILER_FOR_SMALL_REGION(small)->pinned_to_depot == 0);
+ REGION_TRAILER_FOR_SMALL_REGION(small)->pinned_to_depot = 0;
size_t bytes_inplay = small_free_reattach_region(rack, small_depot_ptr, small);
/* Fix up the metadata of the target magazine while the region is in the depot. */
mag_ptr->mag_num_bytes_in_objects -= bytes_inplay;
- mag_ptr->num_bytes_in_magazine -= SMALL_HEAP_SIZE;
+ mag_ptr->num_bytes_in_magazine -= SMALL_REGION_PAYLOAD_BYTES;
mag_ptr->mag_num_objects -= objects_in_use;
/* Now we can drop the magazine lock of the source mag. */
SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
small_depot_ptr->mag_num_bytes_in_objects += bytes_inplay;
- small_depot_ptr->num_bytes_in_magazine += SMALL_HEAP_SIZE;
+ small_depot_ptr->num_bytes_in_magazine += SMALL_REGION_PAYLOAD_BYTES;
small_depot_ptr->mag_num_objects -= objects_in_use;
recirc_list_splice_last(rack, small_depot_ptr, REGION_TRAILER_FOR_SMALL_REGION(small));
@@ -1146,18 +1145,31 @@
int objects_in_use = small_free_detach_region(rack, depot_ptr, sparse_region);
if (0 == objects_in_use) {
- if (!rack_region_remove(rack, sparse_region, node)) {
+ // Invalidate the hash table entry for this region with HASHRING_REGION_DEALLOCATED.
+ // Using HASHRING_REGION_DEALLOCATED preserves the collision chain, using HASHRING_OPEN_ENTRY (0) would not.
+ rgnhdl_t pSlot = hash_lookup_region_no_lock(rack->region_generation->hashed_regions,
+ rack->region_generation->num_regions_allocated,
+ rack->region_generation->num_regions_allocated_shift,
+ sparse_region);
+ if (NULL == pSlot) {
+ malloc_zone_error(rack->debug_flags, true, "small_free_try_depot_unmap_no_lock hash lookup failed: %p\n", sparse_region);
return NULL;
}
- depot_ptr->num_bytes_in_magazine -= SMALL_HEAP_SIZE;
+ *pSlot = HASHRING_REGION_DEALLOCATED;
+ depot_ptr->num_bytes_in_magazine -= SMALL_REGION_PAYLOAD_BYTES;
+ // Atomically increment num_regions_dealloc
+#ifdef __LP64___
+ OSAtomicIncrement64(&rack->num_regions_dealloc);
+#else
+ OSAtomicIncrement32((int32_t *)&rack->num_regions_dealloc);
+#endif
// Caller will transfer ownership of the region back to the OS with no locks held
MAGMALLOC_DEALLOCREGION(SMALL_SZONE_FROM_RACK(rack), (void *)sparse_region, (int)SMALL_REGION_SIZE); // DTrace USDT Probe
return sparse_region;
} else {
- malloc_zone_error(rack->debug_flags, true,
- "small_free_try_depot_unmap_no_lock objects_in_use not zero: %d\n", objects_in_use);
+ malloc_zone_error(rack->debug_flags, true, "small_free_try_depot_unmap_no_lock objects_in_use not zero: %d\n", objects_in_use);
return NULL;
}
}
@@ -1207,13 +1219,13 @@
size_t bytes_inplay = small_free_reattach_region(rack, depot_ptr, sparse_region);
small_mag_ptr->mag_num_bytes_in_objects -= bytes_inplay;
- small_mag_ptr->num_bytes_in_magazine -= SMALL_HEAP_SIZE;
+ small_mag_ptr->num_bytes_in_magazine -= SMALL_REGION_PAYLOAD_BYTES;
small_mag_ptr->mag_num_objects -= objects_in_use;
SZONE_MAGAZINE_PTR_UNLOCK(small_mag_ptr); // Unlock the originating magazine
depot_ptr->mag_num_bytes_in_objects += bytes_inplay;
- depot_ptr->num_bytes_in_magazine += SMALL_HEAP_SIZE;
+ depot_ptr->num_bytes_in_magazine += SMALL_REGION_PAYLOAD_BYTES;
depot_ptr->mag_num_objects += objects_in_use;
// connect to Depot as last node
@@ -1222,20 +1234,16 @@
MAGMALLOC_RECIRCREGION(SMALL_SZONE_FROM_RACK(rack), (int)mag_index, (void *)sparse_region, SMALL_REGION_SIZE,
(int)BYTES_USED_FOR_SMALL_REGION(sparse_region)); // DTrace USDT Probe
-#if CONFIG_AGGRESSIVE_MADVISE
- if (!aggressive_madvise_enabled)
-#endif
- {
- // Mark free'd dirty pages with MADV_FREE to reduce memory pressure
- small_free_scan_madvise_free(rack, depot_ptr, sparse_region);
- }
+#if !CONFIG_AGGRESSIVE_MADVISE
+ // Mark free'd dirty pages with MADV_FREE to reduce memory pressure
+ small_free_scan_madvise_free(rack, depot_ptr, sparse_region);
+#endif
// If the region is entirely empty vm_deallocate() it outside the depot lock
region_t r_dealloc = small_free_try_depot_unmap_no_lock(rack, depot_ptr, node);
SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
if (r_dealloc) {
- mvm_deallocate_pages(r_dealloc, SMALL_REGION_SIZE,
- MALLOC_FIX_GUARD_PAGE_FLAGS(rack->debug_flags));
+ mvm_deallocate_pages(r_dealloc, SMALL_REGION_SIZE, 0);
}
return FALSE; // Caller need not unlock the originating magazine
}
@@ -1253,7 +1261,11 @@
region_trailer_t *node = REGION_TRAILER_FOR_SMALL_REGION(region);
size_t bytes_used = node->bytes_used;
- if (DEPOT_MAGAZINE_INDEX != mag_index) {
+ /* FIXME: Would Uniprocessor benefit from recirc and MADV_FREE? */
+ if (rack->num_magazines == 1) { // Uniprocessor, single magazine, so no recirculation necessary
+ /* NOTHING */
+ return TRUE; // Caller must do SZONE_MAGAZINE_PTR_UNLOCK(tiny_mag_ptr)
+ } else if (DEPOT_MAGAZINE_INDEX != mag_index) {
// Emptiness discriminant
if (small_region_below_recirc_threshold(region)) {
/* Region has crossed threshold from density to sparsity. Mark it "suitable" on the
@@ -1271,14 +1283,11 @@
return small_free_do_recirc_to_depot(rack, small_mag_ptr, mag_index);
}
} else {
-#if CONFIG_AGGRESSIVE_MADVISE
- if (!aggressive_madvise_enabled)
-#endif
- {
- // We are free'ing into the depot, so madvise as we do so unless we were madvising every incoming
- // allocation anyway.
- small_madvise_free_range_no_lock(rack, small_mag_ptr, region, freee, msize, headptr, headsize);
- }
+#if !CONFIG_AGGRESSIVE_MADVISE
+ // We are free'ing into the depot, so madvise as we do so unless we were madvising every incoming
+ // allocation anyway.
+ small_madvise_free_range_no_lock(rack, small_mag_ptr, region, freee, msize, headptr, headsize);
+#endif
if (0 < bytes_used || 0 < node->pinned_to_depot) {
/* Depot'd region is still live. Leave it in place on the Depot's recirculation list
@@ -1289,7 +1298,7 @@
region_t r_dealloc = small_free_try_depot_unmap_no_lock(rack, small_mag_ptr, node);
SZONE_MAGAZINE_PTR_UNLOCK(small_mag_ptr);
if (r_dealloc) {
- mvm_deallocate_pages(r_dealloc, SMALL_REGION_SIZE, MALLOC_FIX_GUARD_PAGE_FLAGS(rack->debug_flags));
+ mvm_deallocate_pages(r_dealloc, SMALL_REGION_SIZE, 0);
}
return FALSE; // Caller need not unlock
}
@@ -1304,7 +1313,7 @@
msize_t *meta_headers = SMALL_META_HEADER_FOR_PTR(ptr);
unsigned index = SMALL_META_INDEX_FOR_PTR(ptr);
size_t original_size = SMALL_BYTES_FOR_MSIZE(msize);
- void *next_block = ptr + original_size;
+ unsigned char *next_block = ((unsigned char *)ptr + original_size);
msize_t next_index = index + msize;
MALLOC_TRACE(TRACE_small_free, (uintptr_t)rack, (uintptr_t)small_mag_ptr, (uintptr_t)ptr, SMALL_BYTES_FOR_MSIZE(msize));
@@ -1324,7 +1333,8 @@
#endif
// Check that the region cookie is intact.
- region_check_cookie(region, ®ION_COOKIE_FOR_SMALL_REGION(region));
+ region_trailer_t *trailer = REGION_TRAILER_FOR_SMALL_REGION(region);
+ region_check_cookie(region, trailer);
// We try to coalesce this block with the preceeding one
if (index > 0 && (meta_headers[index - 1] & SMALL_IS_FREE)) {
@@ -1347,7 +1357,7 @@
}
// Try to coalesce with this block with the next block
- if ((next_block < SMALL_REGION_HEAP_END(region)) && (meta_headers[next_index] & SMALL_IS_FREE)) {
+ if ((next_block < SMALL_REGION_END(region)) && (meta_headers[next_index] & SMALL_IS_FREE)) {
msize_t next_msize = meta_headers[next_index] & ~SMALL_IS_FREE;
free_list_t next = small_free_list_find_by_ptr(rack, small_mag_ptr, next_block, next_msize);
small_free_list_remove_ptr(rack, small_mag_ptr, next, next_msize);
@@ -1368,14 +1378,11 @@
small_mag_ptr->mag_num_bytes_in_objects -= original_size;
// Update this region's bytes in use count
- region_trailer_t *trailer = REGION_TRAILER_FOR_SMALL_REGION(region);
size_t bytes_used = trailer->bytes_used - original_size;
trailer->bytes_used = (unsigned int)bytes_used;
#if CONFIG_AGGRESSIVE_MADVISE
- if (aggressive_madvise_enabled) {
- small_madvise_free_range_no_lock(rack, small_mag_ptr, region, freee, msize, original_ptr, original_size);
- }
+ small_madvise_free_range_no_lock(rack, small_mag_ptr, region, freee, msize, original_ptr, original_size);
#endif
// Caller must do SZONE_MAGAZINE_PTR_UNLOCK(tiny_mag_ptr) if this function
@@ -1404,18 +1411,16 @@
small_finalize_region(rack, small_mag_ptr);
}
- small_region_t region = (small_region_t)aligned_address;
-
// Tag the region at "aligned_address" as belonging to us,
// and so put it under the protection of the magazine lock we are holding.
// Do this before advertising "aligned_address" on the hash ring(!)
- MAGAZINE_INDEX_FOR_SMALL_REGION(region) = mag_index;
+ MAGAZINE_INDEX_FOR_SMALL_REGION(aligned_address) = mag_index;
// Insert the new region into the hash ring
- rack_region_insert(rack, region);
-
- small_mag_ptr->mag_last_region = region;
- BYTES_USED_FOR_SMALL_REGION(region) = SMALL_BYTES_FOR_MSIZE(msize);
+ rack_region_insert(rack, (region_t)aligned_address);
+
+ small_mag_ptr->mag_last_region = aligned_address;
+ BYTES_USED_FOR_SMALL_REGION(aligned_address) = SMALL_BYTES_FOR_MSIZE(msize);
#if CONFIG_ASLR_INTERNAL
int offset_msize = malloc_entropy[1] & SMALL_ENTROPY_MASK;
@@ -1424,17 +1429,17 @@
offset_msize = strtol(getenv("MallocASLRForce"), NULL, 0) & SMALL_ENTROPY_MASK;
}
if (getenv("MallocASLRPrint")) {
- malloc_report(ASL_LEVEL_INFO, "Region: %p offset: %d\n", region, offset_msize);
+ malloc_report(ASL_LEVEL_INFO, "Region: %p offset: %d\n", aligned_address, offset_msize);
}
#endif
#else
int offset_msize = 0;
#endif
- ptr = (void *)(SMALL_REGION_HEAP_BASE(region) + SMALL_BYTES_FOR_MSIZE(offset_msize));
+ ptr = (void *)((uintptr_t)aligned_address + SMALL_BYTES_FOR_MSIZE(offset_msize));
small_meta_header_set_in_use(SMALL_META_HEADER_FOR_PTR(ptr), offset_msize, msize);
small_mag_ptr->mag_num_objects++;
small_mag_ptr->mag_num_bytes_in_objects += SMALL_BYTES_FOR_MSIZE(msize);
- small_mag_ptr->num_bytes_in_magazine += SMALL_HEAP_SIZE;
+ small_mag_ptr->num_bytes_in_magazine += SMALL_REGION_PAYLOAD_BYTES;
// add a big free block at the end
small_meta_header_set_in_use(SMALL_META_HEADER_FOR_PTR(ptr), offset_msize + msize, NUM_SMALL_BLOCKS - msize - offset_msize);
@@ -1451,7 +1456,7 @@
#endif
// connect to magazine as last node
- recirc_list_splice_last(rack, small_mag_ptr, REGION_TRAILER_FOR_SMALL_REGION(region));
+ recirc_list_splice_last(rack, small_mag_ptr, REGION_TRAILER_FOR_SMALL_REGION(aligned_address));
return ptr;
}
@@ -1512,8 +1517,7 @@
small_claimed_address(rack_t *rack, void *ptr)
{
region_t r = small_region_for_ptr_no_lock(rack, ptr);
- return r && ptr >= SMALL_REGION_HEAP_BASE(r)
- && ptr < SMALL_REGION_HEAP_END(r);
+ return r && ptr < (void *)SMALL_REGION_END(r);
}
void *
@@ -1612,7 +1616,7 @@
* Try to expand into unused space immediately after this block.
*/
msize_t unused_msize = SMALL_MSIZE_FOR_BYTES(small_mag_ptr->mag_bytes_free_at_end);
- void *unused_start = SMALL_REGION_HEAP_END(SMALL_REGION_FOR_PTR(ptr)) - small_mag_ptr->mag_bytes_free_at_end;
+ void *unused_start = SMALL_REGION_END(SMALL_REGION_FOR_PTR(ptr)) - small_mag_ptr->mag_bytes_free_at_end;
if (small_mag_ptr->mag_last_region == SMALL_REGION_FOR_PTR(ptr)
&& coalesced_msize < unused_msize && unused_start == ptr + old_size) {
// Extend the in-use for this block to the new size
@@ -1675,7 +1679,7 @@
node->bytes_used = (unsigned int)bytes_used;
// Emptiness discriminant
- if (bytes_used < DENSITY_THRESHOLD(SMALL_HEAP_SIZE)) {
+ if (bytes_used < DENSITY_THRESHOLD(SMALL_REGION_PAYLOAD_BYTES)) {
/* After this reallocation the region is still sparse, so it must have been even more so before
* the reallocation. That implies the region is already correctly marked. Do nothing. */
} else {
@@ -1699,9 +1703,9 @@
small_check_region(rack_t *rack, region_t region, size_t region_index,
unsigned counter)
{
- unsigned char *ptr = SMALL_REGION_HEAP_BASE(region);
+ unsigned char *ptr = SMALL_REGION_ADDRESS(region);
msize_t *meta_headers = SMALL_META_HEADER_FOR_PTR(ptr);
- unsigned char *region_end = SMALL_REGION_HEAP_END(region);
+ unsigned char *region_end = SMALL_REGION_END(region);
msize_t prev_free = 0;
unsigned index;
msize_t msize_and_free;
@@ -1775,7 +1779,7 @@
if (SMALL_PREVIOUS_MSIZE(follower) != msize) {
SMALL_CHECK_FAIL("*** invariant broken for small free %p followed by %p in region [%p-%p] "
"(end marker incorrect) should be %d; in fact %d\n",
- ptr, follower, SMALL_REGION_HEAP_BASE(region), region_end, msize, SMALL_PREVIOUS_MSIZE(follower));
+ ptr, follower, SMALL_REGION_ADDRESS(region), region_end, msize, SMALL_PREVIOUS_MSIZE(follower));
return 0;
}
ptr = (unsigned char *)follower;
@@ -1835,20 +1839,20 @@
for (index = 0; index < num_regions; ++index) {
region = regions[index];
if (HASHRING_OPEN_ENTRY != region && HASHRING_REGION_DEALLOCATED != region) {
- range.address = (vm_address_t)SMALL_REGION_HEAP_BASE(region);
- range.size = SMALL_HEAP_SIZE;
+ range.address = (vm_address_t)SMALL_REGION_ADDRESS(region);
+ range.size = SMALL_REGION_SIZE;
if (type_mask & MALLOC_ADMIN_REGION_RANGE_TYPE) {
- admin_range.address = SMALL_REGION_METADATA(region);
+ admin_range.address = range.address + SMALL_METADATA_START;
admin_range.size = SMALL_METADATA_SIZE;
recorder(task, context, MALLOC_ADMIN_REGION_RANGE_TYPE, &admin_range, 1);
}
if (type_mask & (MALLOC_PTR_REGION_RANGE_TYPE | MALLOC_ADMIN_REGION_RANGE_TYPE)) {
ptr_range.address = range.address;
- ptr_range.size = SMALL_HEAP_SIZE;
+ ptr_range.size = NUM_SMALL_BLOCKS * SMALL_QUANTUM;
recorder(task, context, MALLOC_PTR_REGION_RANGE_TYPE, &ptr_range, 1);
}
if (type_mask & MALLOC_PTR_IN_USE_RANGE_TYPE) {
- err = reader(task, (vm_address_t)region, (vm_size_t)SMALL_REGION_SIZE, (void **)&mapped_region);
+ err = reader(task, range.address, range.size, (void **)&mapped_region);
if (err) {
return err;
}
@@ -1861,13 +1865,13 @@
// Each magazine could have a pointer to a cached free block from
// this region. Count the regions that have such a pointer.
for (mag_index = 0; mag_index < szone->small_rack.num_magazines; mag_index++) {
- if (region == (small_mag_base + mag_index)->mag_last_free_rgn) {
+ if ((void *)range.address == (small_mag_base + mag_index)->mag_last_free_rgn) {
cached_free_blocks++;
}
}
#endif // CONFIG_SMALL_CACHE
- block_header = SMALL_META_HEADER_FOR_REGION(mapped_region);
+ block_header = (msize_t *)(mapped_region + SMALL_METADATA_START + sizeof(region_trailer_t));
block_index = 0;
block_limit = NUM_SMALL_BLOCKS;
if (region == small_mag_ptr->mag_last_region) {
@@ -1882,7 +1886,7 @@
return KERN_FAILURE; // Somethings amiss. Avoid looping at this block_index.
}
if (!(msize_and_free & SMALL_IS_FREE)) {
- void *ptr = SMALL_REGION_HEAP_BASE(region) + SMALL_BYTES_FOR_MSIZE(block_index);
+ vm_address_t ptr = range.address + SMALL_BYTES_FOR_MSIZE(block_index);
#if CONFIG_SMALL_CACHE
// If there are still magazines that have cached free
// blocks in this region, check whether this is one of
@@ -1890,7 +1894,7 @@
boolean_t block_cached = false;
if (cached_free_blocks) {
for (mag_index = 0; mag_index < szone->small_rack.num_magazines; mag_index++) {
- if (ptr == (small_mag_base + mag_index)->mag_last_free) {
+ if ((void *)ptr == (small_mag_base + mag_index)->mag_last_free) {
block_cached = true;
cached_free_blocks--;
break;
@@ -1902,7 +1906,7 @@
}
#endif // CONFIG_SMALL_CACHE
// Block in use
- buffer[count].address = (vm_address_t)ptr;
+ buffer[count].address = ptr;
buffer[count].size = SMALL_BYTES_FOR_MSIZE(msize);
count++;
if (count >= MAX_RECORDER_BUFFER) {
@@ -1987,7 +1991,7 @@
try_small_from_end:
// Let's see if we can use small_mag_ptr->mag_bytes_free_at_end
if (small_mag_ptr->mag_bytes_free_at_end >= SMALL_BYTES_FOR_MSIZE(msize)) {
- ptr = SMALL_REGION_HEAP_END(small_mag_ptr->mag_last_region) - small_mag_ptr->mag_bytes_free_at_end;
+ ptr = SMALL_REGION_END(small_mag_ptr->mag_last_region) - small_mag_ptr->mag_bytes_free_at_end;
small_mag_ptr->mag_bytes_free_at_end -= SMALL_BYTES_FOR_MSIZE(msize);
if (small_mag_ptr->mag_bytes_free_at_end) {
// let's mark this block as in use to serve as boundary
@@ -2001,13 +2005,13 @@
#if CONFIG_ASLR_INTERNAL
// Try from start if nothing left at end
if (small_mag_ptr->mag_bytes_free_at_start >= SMALL_BYTES_FOR_MSIZE(msize)) {
- ptr = SMALL_REGION_HEAP_BASE(small_mag_ptr->mag_last_region) + small_mag_ptr->mag_bytes_free_at_start -
+ ptr = SMALL_REGION_ADDRESS(small_mag_ptr->mag_last_region) + small_mag_ptr->mag_bytes_free_at_start -
SMALL_BYTES_FOR_MSIZE(msize);
small_mag_ptr->mag_bytes_free_at_start -= SMALL_BYTES_FOR_MSIZE(msize);
if (small_mag_ptr->mag_bytes_free_at_start) {
// let's mark this block as in use to serve as boundary
- small_meta_header_set_in_use(SMALL_META_HEADER_FOR_PTR(ptr), 0,
- SMALL_MSIZE_FOR_BYTES(small_mag_ptr->mag_bytes_free_at_start));
+ small_meta_header_set_in_use(
+ SMALL_META_HEADER_FOR_PTR(ptr), 0, SMALL_MSIZE_FOR_BYTES(small_mag_ptr->mag_bytes_free_at_start));
}
this_msize = msize;
goto return_small_alloc;
@@ -2033,15 +2037,14 @@
small_mag_ptr->mag_num_bytes_in_objects += SMALL_BYTES_FOR_MSIZE(this_msize);
// Check that the region cookie is intact and update the region's bytes in use count
- small_region_t region = SMALL_REGION_FOR_PTR(ptr);
- region_check_cookie(region, ®ION_COOKIE_FOR_SMALL_REGION(region));
-
+ region_t *region = SMALL_REGION_FOR_PTR(ptr);
region_trailer_t *trailer = REGION_TRAILER_FOR_SMALL_REGION(region);
+ region_check_cookie(region, trailer);
size_t bytes_used = trailer->bytes_used + SMALL_BYTES_FOR_MSIZE(this_msize);
trailer->bytes_used = (unsigned int)bytes_used;
// Emptiness discriminant
- if (bytes_used < DENSITY_THRESHOLD(SMALL_HEAP_SIZE)) {
+ if (bytes_used < DENSITY_THRESHOLD(SMALL_REGION_PAYLOAD_BYTES)) {
/* After this allocation the region is still sparse, so it must have been even more so before
* the allocation. That implies the region is already correctly marked. Do nothing. */
} else {
@@ -2062,7 +2065,7 @@
small_malloc_should_clear(rack_t *rack, msize_t msize, boolean_t cleared_requested)
{
void *ptr;
- mag_index_t mag_index = rack_get_thread_index(rack) % rack->num_magazines;
+ mag_index_t mag_index = small_mag_get_thread_index() % rack->num_magazines;
magazine_t *small_mag_ptr = &(rack->magazines[mag_index]);
MALLOC_TRACE(TRACE_small_malloc, (uintptr_t)rack, SMALL_BYTES_FOR_MSIZE(msize), (uintptr_t)small_mag_ptr, cleared_requested);
@@ -2113,51 +2116,42 @@
// The magazine is exhausted. A new region (heap) must be allocated to satisfy this call to malloc().
// The allocation, an mmap() system call, will be performed outside the magazine spin locks by the first
- // thread that suffers the exhaustion. That thread accquires the magazine_alloc_lock, then drops the
- // magazine lock to allow freeing threads to proceed. Allocating thrads that arrive later are excluded
- // from the critial section by the alloc lock. When those are unblocked, they succeed in the code above.
- //
- // Note that we need to trylock the alloc lock to avoid a deadlock, since we can't block on the alloc
- // lock while holding the magazine lock
- if (os_likely(_malloc_lock_trylock(&small_mag_ptr->magazine_alloc_lock))) {
- // We got the alloc lock, so we are the thread that should allocate a new region
+ // thread that suffers the exhaustion. That thread sets "alloc_underway" and enters a critical section.
+ // Threads arriving here later are excluded from the critical section, yield the CPU, and then retry the
+ // allocation. After some time the magazine is resupplied, the original thread leaves with its allocation,
+ // and retry-ing threads succeed in the code just above.
+ if (!small_mag_ptr->alloc_underway) {
void *fresh_region;
// time to create a new region (do this outside the magazine lock)
+ small_mag_ptr->alloc_underway = TRUE;
+ OSMemoryBarrier();
SZONE_MAGAZINE_PTR_UNLOCK(small_mag_ptr);
- fresh_region = mvm_allocate_pages(SMALL_REGION_SIZE,
- SMALL_BLOCKS_ALIGN,
- MALLOC_FIX_GUARD_PAGE_FLAGS(rack->debug_flags),
- VM_MEMORY_MALLOC_SMALL);
+ fresh_region = mvm_allocate_pages_securely(SMALL_REGION_SIZE, SMALL_BLOCKS_ALIGN, VM_MEMORY_MALLOC_SMALL, rack->debug_flags);
SZONE_MAGAZINE_PTR_LOCK(small_mag_ptr);
// DTrace USDT Probe
MAGMALLOC_ALLOCREGION(SMALL_SZONE_FROM_RACK(rack), (int)mag_index, fresh_region, SMALL_REGION_SIZE);
if (!fresh_region) { // out of memory!
+ small_mag_ptr->alloc_underway = FALSE;
+ OSMemoryBarrier();
SZONE_MAGAZINE_PTR_UNLOCK(small_mag_ptr);
- _malloc_lock_unlock(&small_mag_ptr->magazine_alloc_lock);
return NULL;
}
- region_set_cookie(®ION_COOKIE_FOR_SMALL_REGION(fresh_region));
+ region_set_cookie(REGION_TRAILER_FOR_SMALL_REGION(fresh_region));
ptr = small_malloc_from_region_no_lock(rack, small_mag_ptr, mag_index, msize, fresh_region);
// we don't clear because this freshly allocated space is pristine
+ small_mag_ptr->alloc_underway = FALSE;
+ OSMemoryBarrier();
SZONE_MAGAZINE_PTR_UNLOCK(small_mag_ptr);
- _malloc_lock_unlock(&small_mag_ptr->magazine_alloc_lock);
CHECK(szone, __PRETTY_FUNCTION__);
return ptr;
} else {
- // We failed to get the alloc lock, so someone else is allocating.
- // Drop the magazine lock...
SZONE_MAGAZINE_PTR_UNLOCK(small_mag_ptr);
-
- // Wait for the other thread on the alloc lock
- _malloc_lock_lock(&small_mag_ptr->magazine_alloc_lock);
- _malloc_lock_unlock(&small_mag_ptr->magazine_alloc_lock);
-
- // Reacquire the magazine lock to go around the loop again
+ yield();
SZONE_MAGAZINE_PTR_LOCK(small_mag_ptr);
}
}
@@ -2204,6 +2198,9 @@
static MALLOC_NOINLINE void
free_small_botch(rack_t *rack, void *ptr)
{
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_SMALL_REGION(SMALL_REGION_FOR_PTR(ptr));
+ magazine_t *small_mag_ptr = &(rack->magazines[mag_index]);
+ SZONE_MAGAZINE_PTR_UNLOCK(small_mag_ptr);
malloc_zone_error(rack->debug_flags, true, "double free for ptr %p\n", ptr);
}
@@ -2236,7 +2233,6 @@
/* check that we don't already have this pointer in the cache */
if (ptr == ptr2) {
- SZONE_MAGAZINE_PTR_UNLOCK(small_mag_ptr);
free_small_botch(rack, ptr);
return;
}
@@ -2341,9 +2337,9 @@
{
unsigned counts[1024];
unsigned in_use = 0;
- uintptr_t start = (uintptr_t)SMALL_REGION_HEAP_BASE(region);
+ uintptr_t start = (uintptr_t)SMALL_REGION_ADDRESS(region);
uintptr_t current = start + bytes_at_start;
- uintptr_t limit = (uintptr_t)SMALL_REGION_HEAP_END(region) - bytes_at_end;
+ uintptr_t limit = (uintptr_t)SMALL_REGION_END(region) - bytes_at_end;
uintptr_t mapped_start;
msize_t msize_and_free;
msize_t msize;
@@ -2398,8 +2394,8 @@
if ((b = _simple_salloc()) != NULL) {
mag_index_t mag_index = MAGAZINE_INDEX_FOR_SMALL_REGION(mapped_region);
- _simple_sprintf(b, "Small region %p [%p-%p, %y] \t", region, (void *)start,
- SMALL_REGION_HEAP_END(region), (int)SMALL_REGION_SIZE);
+ _simple_sprintf(b, "Small region [%p-%p, %y] \t", (void *)start,
+ SMALL_REGION_END(region), (int)SMALL_REGION_SIZE);
if (mag_index == DEPOT_MAGAZINE_INDEX) {
_simple_sprintf(b, "Recirc depot \t");
} else {