merge from dev

src/arena.c

@@ -140,10 +140,10 @@ static bool mi_arena_memid_indices(mi_memid_t memid, size_t* arena_index, mi_bit
 
 /* -----------------------------------------------------------
   Special static area for mimalloc internal structures
-  to avoid OS calls (for example, for the arena metadata)
+  to avoid OS calls (for example, for the arena metadata (~= 256b))
 ----------------------------------------------------------- */
 
-#define MI_ARENA_STATIC_MAX  (MI_INTPTR_SIZE*MI_KiB)  // 8 KiB on 64-bit
+#define MI_ARENA_STATIC_MAX  ((MI_INTPTR_SIZE/2)*MI_KiB)  // 4 KiB on 64-bit
 
 static mi_decl_cache_align uint8_t mi_arena_static[MI_ARENA_STATIC_MAX];  // must be cache aligned, see issue #895
 static mi_decl_cache_align _Atomic(size_t) mi_arena_static_top;

src/init.c

@@ -271,7 +271,7 @@ typedef struct mi_thread_data_s {
 // destroy many OS threads, this may causes too much overhead
 // per thread so we maintain a small cache of recently freed metadata.
 
-#define TD_CACHE_SIZE (16)
+#define TD_CACHE_SIZE (32)
 static _Atomic(mi_thread_data_t*) td_cache[TD_CACHE_SIZE];
 
 static mi_thread_data_t* mi_thread_data_zalloc(void) {

src/segment.c

@@ -407,7 +407,6 @@ static void mi_segment_os_free(mi_segment_t* segment, mi_segments_tld_t* tld) {
   const size_t size = mi_segment_size(segment);
   const size_t csize = _mi_commit_mask_committed_size(&segment->commit_mask, size);
 
-  _mi_abandoned_await_readers();  // wait until safe to free
   _mi_arena_free(segment, mi_segment_size(segment), csize, segment->memid, tld->stats);
 }
 
@@ -1067,11 +1066,6 @@ by scanning the arena memory
 (segments outside arena memoryare only reclaimed by a free).
 ----------------------------------------------------------- */
 
-// legacy: Wait until there are no more pending reads on segments that used to be in the abandoned list
-void _mi_abandoned_await_readers(void) {
-  // nothing needed
-}
-
 /* -----------------------------------------------------------
    Abandon segment/page
 ----------------------------------------------------------- */