Cleanup cache_bin_info_t* info input args

1. Pre-generate all default tcache ncached_max in tcache_boot;
2. Add getters returning default ncached_max and ncached_max_set;
3. Refactor tcache init so that it is always init with a given setting.

Makefile.in

@@ -155,6 +155,7 @@ C_SRCS := $(srcroot)src/jemalloc.c \
 	$(srcroot)src/thread_event.c \
 	$(srcroot)src/ticker.c \
 	$(srcroot)src/tsd.c \
+	$(srcroot)src/util.c \
 	$(srcroot)src/witness.c
 ifeq ($(enable_zone_allocator), 1)
 C_SRCS += $(srcroot)src/zone.c
@@ -241,6 +242,7 @@ TESTS_UNIT := \
 	$(srcroot)test/unit/mq.c \
 	$(srcroot)test/unit/mtx.c \
 	$(srcroot)test/unit/nstime.c \
+	$(srcroot)test/unit/ncached_max.c \
 	$(srcroot)test/unit/oversize_threshold.c \
 	$(srcroot)test/unit/pa.c \
 	$(srcroot)test/unit/pack.c \

include/jemalloc/internal/arena_externs.h

@@ -63,8 +63,7 @@ void arena_do_deferred_work(tsdn_t *tsdn, arena_t *arena);
 void arena_reset(tsd_t *tsd, arena_t *arena);
 void arena_destroy(tsd_t *tsd, arena_t *arena);
 void arena_cache_bin_fill_small(tsdn_t *tsdn, arena_t *arena,
-    cache_bin_t *cache_bin, cache_bin_info_t *cache_bin_info, szind_t binind,
+    cache_bin_t *cache_bin, szind_t binind, const unsigned nfill);
-    const unsigned nfill);
 
 void *arena_malloc_hard(tsdn_t *tsdn, arena_t *arena, size_t size,
     szind_t ind, bool zero, bool slab);

include/jemalloc/internal/arena_inlines_b.h

@@ -198,7 +198,8 @@ arena_malloc(tsdn_t *tsdn, arena_t *arena, size_t size, szind_t ind, bool zero,
 			assert(sz_can_use_slab(size));
 			return tcache_alloc_small(tsdn_tsd(tsdn), arena,
 			    tcache, size, ind, zero, slow_path);
-		} else if (likely(ind < TCACHE_NBINS_MAX &&
+		} else if (likely(
+		    ind < tcache_nbins_get(tcache->tcache_slow) &&
 		    !tcache_bin_disabled(ind, &tcache->bins[ind],
 		    tcache->tcache_slow))) {
 			return tcache_alloc_large(tsdn_tsd(tsdn), arena,
@@ -300,24 +301,25 @@ JEMALLOC_ALWAYS_INLINE void
 arena_dalloc_large(tsdn_t *tsdn, void *ptr, tcache_t *tcache, szind_t szind,
     bool slow_path) {
 	assert (!tsdn_null(tsdn) && tcache != NULL);
-	if (szind < TCACHE_NBINS_MAX &&
+	bool is_sample_promoted = config_prof && szind < SC_NBINS;
-	    !tcache_bin_disabled(szind, &tcache->bins[szind],
+	if (unlikely(is_sample_promoted)) {
-	    tcache->tcache_slow)) {
-		if (config_prof && unlikely(szind < SC_NBINS)) {
 		arena_dalloc_promoted(tsdn, ptr, tcache, slow_path);
 	} else {
+		if (szind < tcache_nbins_get(tcache->tcache_slow) &&
+		    !tcache_bin_disabled(szind, &tcache->bins[szind],
+		    tcache->tcache_slow)) {
 			tcache_dalloc_large(tsdn_tsd(tsdn), tcache, ptr, szind,
 			    slow_path);
-		}
 		} else {
-		edata_t *edata = emap_edata_lookup(tsdn, &arena_emap_global,
+			edata_t *edata = emap_edata_lookup(tsdn,
-		    ptr);
+			    &arena_emap_global, ptr);
 			if (large_dalloc_safety_checks(edata, ptr, szind)) {
 				/* See the comment in isfree. */
 				return;
 			}
 			large_dalloc(tsdn, edata);
 		}
+	}
 }
 
 /* Find the region index of a pointer. */

include/jemalloc/internal/arena_structs.h

@@ -98,9 +98,12 @@ struct arena_s {
 	/*
 	 * The arena is allocated alongside its bins; really this is a
 	 * dynamically sized array determined by the binshard settings.
+	 * Enforcing cacheline-alignment to minimize the number of cachelines
+	 * touched on the hot paths.
 	 */
 	JEMALLOC_WARN_ON_USAGE("Do not use this field directly. "
 	                       "Use `arena_get_bin` instead.")
+	JEMALLOC_ALIGNED(CACHELINE)
 	bin_t			all_bins[0];
 };
 

include/jemalloc/internal/cache_bin.h

@@ -202,12 +202,17 @@ cache_bin_disabled(cache_bin_t *bin) {
 	return disabled;
 }
 
+/* Gets ncached_max without asserting that the bin is enabled. */
+static inline cache_bin_sz_t
+cache_bin_ncached_max_get_unsafe(cache_bin_t *bin) {
+	return bin->bin_info.ncached_max;
+}
+
 /* Returns ncached_max: Upper limit on ncached. */
 static inline cache_bin_sz_t
-cache_bin_info_ncached_max_get(cache_bin_t *bin, cache_bin_info_t *info) {
+cache_bin_ncached_max_get(cache_bin_t *bin) {
 	assert(!cache_bin_disabled(bin));
-	assert(info == &bin->bin_info);
+	return cache_bin_ncached_max_get_unsafe(bin);
-	return info->ncached_max;
 }
 
 /*
@@ -229,7 +234,7 @@ cache_bin_assert_earlier(cache_bin_t *bin, uint16_t earlier, uint16_t later) {
  * Does difference calculations that handle wraparound correctly.  Earlier must
  * be associated with the position earlier in memory.
  */
-static inline uint16_t
+static inline cache_bin_sz_t
 cache_bin_diff(cache_bin_t *bin, uint16_t earlier, uint16_t later) {
 	cache_bin_assert_earlier(bin, earlier, later);
 	return later - earlier;
@@ -262,9 +267,9 @@ cache_bin_ncached_get_internal(cache_bin_t *bin) {
  * possible.
  */
 static inline cache_bin_sz_t
-cache_bin_ncached_get_local(cache_bin_t *bin, cache_bin_info_t *info) {
+cache_bin_ncached_get_local(cache_bin_t *bin) {
 	cache_bin_sz_t n = cache_bin_ncached_get_internal(bin);
-	assert(n <= cache_bin_info_ncached_max_get(bin, info));
+	assert(n <= cache_bin_ncached_max_get(bin));
 	return n;
 }
 
@@ -299,9 +304,9 @@ cache_bin_empty_position_get(cache_bin_t *bin) {
  * arena statistics collection.
  */
 static inline uint16_t
-cache_bin_low_bits_low_bound_get(cache_bin_t *bin, cache_bin_info_t *info) {
+cache_bin_low_bits_low_bound_get(cache_bin_t *bin) {
 	return (uint16_t)bin->low_bits_empty -
-	    cache_bin_info_ncached_max_get(bin, info) * sizeof(void *);
+	    cache_bin_ncached_max_get(bin) * sizeof(void *);
 }
 
 /*
@@ -310,8 +315,8 @@ cache_bin_low_bits_low_bound_get(cache_bin_t *bin, cache_bin_info_t *info) {
  * A pointer to the position with the lowest address of the backing array.
  */
 static inline void **
-cache_bin_low_bound_get(cache_bin_t *bin, cache_bin_info_t *info) {
+cache_bin_low_bound_get(cache_bin_t *bin) {
-	cache_bin_sz_t ncached_max = cache_bin_info_ncached_max_get(bin, info);
+	cache_bin_sz_t ncached_max = cache_bin_ncached_max_get(bin);
 	void **ret = cache_bin_empty_position_get(bin) - ncached_max;
 	assert(ret <= bin->stack_head);
 
@@ -323,8 +328,8 @@ cache_bin_low_bound_get(cache_bin_t *bin, cache_bin_info_t *info) {
  * batch fill a nonempty cache bin.
  */
 static inline void
-cache_bin_assert_empty(cache_bin_t *bin, cache_bin_info_t *info) {
+cache_bin_assert_empty(cache_bin_t *bin) {
-	assert(cache_bin_ncached_get_local(bin, info) == 0);
+	assert(cache_bin_ncached_get_local(bin) == 0);
 	assert(cache_bin_empty_position_get(bin) == bin->stack_head);
 }
 
@@ -341,10 +346,10 @@ cache_bin_low_water_get_internal(cache_bin_t *bin) {
 
 /* Returns the numeric value of low water in [0, ncached]. */
 static inline cache_bin_sz_t
-cache_bin_low_water_get(cache_bin_t *bin, cache_bin_info_t *info) {
+cache_bin_low_water_get(cache_bin_t *bin) {
 	cache_bin_sz_t low_water = cache_bin_low_water_get_internal(bin);
-	assert(low_water <= cache_bin_info_ncached_max_get(bin, info));
+	assert(low_water <= cache_bin_ncached_max_get(bin));
-	assert(low_water <= cache_bin_ncached_get_local(bin, info));
+	assert(low_water <= cache_bin_ncached_get_local(bin));
 
 	cache_bin_assert_earlier(bin, (uint16_t)(uintptr_t)bin->stack_head,
 	    bin->low_bits_low_water);
@@ -525,17 +530,16 @@ cache_bin_stash(cache_bin_t *bin, void *ptr) {
 
 /* Get the number of stashed pointers. */
 JEMALLOC_ALWAYS_INLINE cache_bin_sz_t
-cache_bin_nstashed_get_internal(cache_bin_t *bin, cache_bin_info_t *info) {
+cache_bin_nstashed_get_internal(cache_bin_t *bin) {
-	cache_bin_sz_t ncached_max = cache_bin_info_ncached_max_get(bin, info);
+	cache_bin_sz_t ncached_max = cache_bin_ncached_max_get(bin);
-	uint16_t low_bits_low_bound = cache_bin_low_bits_low_bound_get(bin,
+	uint16_t low_bits_low_bound = cache_bin_low_bits_low_bound_get(bin);
-	    info);
 
 	cache_bin_sz_t n = cache_bin_diff(bin, low_bits_low_bound,
 	    bin->low_bits_full) / sizeof(void *);
 	assert(n <= ncached_max);
 	if (config_debug && n != 0) {
 		/* Below are for assertions only. */
-		void **low_bound = cache_bin_low_bound_get(bin, info);
+		void **low_bound = cache_bin_low_bound_get(bin);
 
 		assert((uint16_t)(uintptr_t)low_bound == low_bits_low_bound);
 		void *stashed = *(low_bound + n - 1);
@@ -551,9 +555,9 @@ cache_bin_nstashed_get_internal(cache_bin_t *bin, cache_bin_info_t *info) {
 }
 
 JEMALLOC_ALWAYS_INLINE cache_bin_sz_t
-cache_bin_nstashed_get_local(cache_bin_t *bin, cache_bin_info_t *info) {
+cache_bin_nstashed_get_local(cache_bin_t *bin) {
-	cache_bin_sz_t n = cache_bin_nstashed_get_internal(bin, info);
+	cache_bin_sz_t n = cache_bin_nstashed_get_internal(bin);
-	assert(n <= cache_bin_info_ncached_max_get(bin, info));
+	assert(n <= cache_bin_ncached_max_get(bin));
 	return n;
 }
 
@@ -574,29 +578,26 @@ cache_bin_nstashed_get_local(cache_bin_t *bin, cache_bin_info_t *info) {
  * This function should not call other utility functions because the racy
  * condition may cause unexpected / undefined behaviors in unverified utility
  * functions.  Currently, this function calls two utility functions
- * cache_bin_info_ncached_max_get and cache_bin_low_bits_low_bound_get because
+ * cache_bin_ncached_max_get and cache_bin_low_bits_low_bound_get because
  * they help access values that will not be concurrently modified.
  */
 static inline void
-cache_bin_nitems_get_remote(cache_bin_t *bin, cache_bin_info_t *info,
+cache_bin_nitems_get_remote(cache_bin_t *bin, cache_bin_sz_t *ncached,
-    cache_bin_sz_t *ncached, cache_bin_sz_t *nstashed) {
+    cache_bin_sz_t *nstashed) {
 	/* Racy version of cache_bin_ncached_get_internal. */
 	cache_bin_sz_t diff = bin->low_bits_empty -
 	    (uint16_t)(uintptr_t)bin->stack_head;
 	cache_bin_sz_t n = diff / sizeof(void *);
-
-	cache_bin_sz_t ncached_max = cache_bin_info_ncached_max_get(bin, info);
-	assert(n <= ncached_max);
 	*ncached = n;
 
 	/* Racy version of cache_bin_nstashed_get_internal. */
-	uint16_t low_bits_low_bound = cache_bin_low_bits_low_bound_get(bin,
+	uint16_t low_bits_low_bound = cache_bin_low_bits_low_bound_get(bin);
-	    info);
 	n = (bin->low_bits_full - low_bits_low_bound) / sizeof(void *);
-
-	assert(n <= ncached_max);
 	*nstashed = n;
-	/* Note that cannot assert ncached + nstashed <= ncached_max (racy). */
+	/*
+	 * Note that cannot assert anything regarding ncached_max because
+	 * it can be configured on the fly and is thus racy.
+	 */
 }
 
 /*
@@ -640,9 +641,9 @@ struct cache_bin_ptr_array_s {
  * finish_fill call before doing any alloc/dalloc operations on the bin.
  */
 static inline void
-cache_bin_init_ptr_array_for_fill(cache_bin_t *bin, cache_bin_info_t *info,
+cache_bin_init_ptr_array_for_fill(cache_bin_t *bin, cache_bin_ptr_array_t *arr,
-    cache_bin_ptr_array_t *arr, cache_bin_sz_t nfill) {
+    cache_bin_sz_t nfill) {
-	cache_bin_assert_empty(bin, info);
+	cache_bin_assert_empty(bin);
 	arr->ptr = cache_bin_empty_position_get(bin) - nfill;
 }
 
@@ -652,9 +653,9 @@ cache_bin_init_ptr_array_for_fill(cache_bin_t *bin, cache_bin_info_t *info,
  * case of OOM.
  */
 static inline void
-cache_bin_finish_fill(cache_bin_t *bin, cache_bin_info_t *info,
+cache_bin_finish_fill(cache_bin_t *bin, cache_bin_ptr_array_t *arr,
-    cache_bin_ptr_array_t *arr, cache_bin_sz_t nfilled) {
+    cache_bin_sz_t nfilled) {
-	cache_bin_assert_empty(bin, info);
+	cache_bin_assert_empty(bin);
 	void **empty_position = cache_bin_empty_position_get(bin);
 	if (nfilled < arr->n) {
 		memmove(empty_position - nfilled, empty_position - arr->n,
@@ -668,17 +669,17 @@ cache_bin_finish_fill(cache_bin_t *bin, cache_bin_info_t *info,
  * everything we give them.
  */
 static inline void
-cache_bin_init_ptr_array_for_flush(cache_bin_t *bin, cache_bin_info_t *info,
+cache_bin_init_ptr_array_for_flush(cache_bin_t *bin,
     cache_bin_ptr_array_t *arr, cache_bin_sz_t nflush) {
 	arr->ptr = cache_bin_empty_position_get(bin) - nflush;
-	assert(cache_bin_ncached_get_local(bin, info) == 0
+	assert(cache_bin_ncached_get_local(bin) == 0
 	    || *arr->ptr != NULL);
 }
 
 static inline void
-cache_bin_finish_flush(cache_bin_t *bin, cache_bin_info_t *info,
+cache_bin_finish_flush(cache_bin_t *bin, cache_bin_ptr_array_t *arr,
-    cache_bin_ptr_array_t *arr, cache_bin_sz_t nflushed) {
+    cache_bin_sz_t nflushed) {
-	unsigned rem = cache_bin_ncached_get_local(bin, info) - nflushed;
+	unsigned rem = cache_bin_ncached_get_local(bin) - nflushed;
 	memmove(bin->stack_head + nflushed, bin->stack_head,
 	    rem * sizeof(void *));
 	bin->stack_head += nflushed;
@@ -687,23 +688,22 @@ cache_bin_finish_flush(cache_bin_t *bin, cache_bin_info_t *info,
 
 static inline void
 cache_bin_init_ptr_array_for_stashed(cache_bin_t *bin, szind_t binind,
-    cache_bin_info_t *info, cache_bin_ptr_array_t *arr,
+    cache_bin_ptr_array_t *arr, cache_bin_sz_t nstashed) {
-    cache_bin_sz_t nstashed) {
 	assert(nstashed > 0);
-	assert(cache_bin_nstashed_get_local(bin, info) == nstashed);
+	assert(cache_bin_nstashed_get_local(bin) == nstashed);
 
-	void **low_bound = cache_bin_low_bound_get(bin, info);
+	void **low_bound = cache_bin_low_bound_get(bin);
 	arr->ptr = low_bound;
 	assert(*arr->ptr != NULL);
 }
 
 static inline void
-cache_bin_finish_flush_stashed(cache_bin_t *bin, cache_bin_info_t *info) {
+cache_bin_finish_flush_stashed(cache_bin_t *bin) {
-	void **low_bound = cache_bin_low_bound_get(bin, info);
+	void **low_bound = cache_bin_low_bound_get(bin);
 
 	/* Reset the bin local full position. */
 	bin->low_bits_full = (uint16_t)(uintptr_t)low_bound;
-	assert(cache_bin_nstashed_get_local(bin, info) == 0);
+	assert(cache_bin_nstashed_get_local(bin) == 0);
 }
 
 /*
@@ -716,8 +716,8 @@ void cache_bin_info_init(cache_bin_info_t *bin_info,
  * Given an array of initialized cache_bin_info_ts, determine how big an
  * allocation is required to initialize a full set of cache_bin_ts.
  */
-void cache_bin_info_compute_alloc(cache_bin_info_t *infos, szind_t ninfos,
+void cache_bin_info_compute_alloc(const cache_bin_info_t *infos,
-    size_t *size, size_t *alignment);
+    szind_t ninfos, size_t *size, size_t *alignment);
 
 /*
  * Actually initialize some cache bins.  Callers should allocate the backing
@@ -726,11 +726,11 @@ void cache_bin_info_compute_alloc(cache_bin_info_t *infos, szind_t ninfos,
  * cache_bin_postincrement.  *alloc_cur will then point immediately past the end
  * of the allocation.
  */
-void cache_bin_preincrement(cache_bin_info_t *infos, szind_t ninfos,
+void cache_bin_preincrement(const cache_bin_info_t *infos, szind_t ninfos,
     void *alloc, size_t *cur_offset);
 void cache_bin_postincrement(void *alloc, size_t *cur_offset);
-void cache_bin_init(cache_bin_t *bin, cache_bin_info_t *info, void *alloc,
+void cache_bin_init(cache_bin_t *bin, const cache_bin_info_t *info,
-    size_t *cur_offset);
+    void *alloc, size_t *cur_offset);
 void cache_bin_init_disabled(cache_bin_t *bin, cache_bin_sz_t ncached_max);
 
 bool cache_bin_stack_use_thp(void);

include/jemalloc/internal/ctl.h

@@ -14,6 +14,7 @@
 
 /* Maximum ctl tree depth. */
 #define CTL_MAX_DEPTH	7
+#define CTL_MULTI_SETTING_MAX_LEN 1000
 
 typedef struct ctl_node_s {
 	bool named;

include/jemalloc/internal/jemalloc_internal_macros.h

@@ -37,8 +37,10 @@
 /* Various function pointers are static and immutable except during testing. */
 #ifdef JEMALLOC_JET
 #  define JET_MUTABLE
+#  define JET_EXTERN extern
 #else
 #  define JET_MUTABLE const
+#  define JET_EXTERN static
 #endif
 
 #define JEMALLOC_VA_ARGS_HEAD(head, ...) head

include/jemalloc/internal/mutex.h

@@ -32,6 +32,12 @@ struct malloc_mutex_s {
 			 * unlocking thread).
 			 */
 			mutex_prof_data_t	prof_data;
+			/*
+			 * Hint flag to avoid exclusive cache line contention
+			 * during spin waiting.  Placed along with prof_data
+			 * since it's always modified even with no contention.
+			 */
+			atomic_b_t		locked;
 #ifdef _WIN32
 #  if _WIN32_WINNT >= 0x0600
 			SRWLOCK         	lock;
@@ -46,11 +52,6 @@ struct malloc_mutex_s {
 #else
 			pthread_mutex_t		lock;
 #endif
-			/*
-			 * Hint flag to avoid exclusive cache line contention
-			 * during spin waiting
-			 */
-			atomic_b_t		locked;
 		};
 		/*
 		 * We only touch witness when configured w/ debug.  However we
@@ -99,21 +100,21 @@ struct malloc_mutex_s {
 #elif (defined(JEMALLOC_OS_UNFAIR_LOCK))
 #  if defined(JEMALLOC_DEBUG)
 #    define MALLOC_MUTEX_INITIALIZER					\
-  {{{LOCK_PROF_DATA_INITIALIZER, OS_UNFAIR_LOCK_INIT, ATOMIC_INIT(false)}}, \
+  {{{LOCK_PROF_DATA_INITIALIZER, ATOMIC_INIT(false), OS_UNFAIR_LOCK_INIT}}, \
          WITNESS_INITIALIZER("mutex", WITNESS_RANK_OMIT), 0}
 #  else
 #    define MALLOC_MUTEX_INITIALIZER                      \
-  {{{LOCK_PROF_DATA_INITIALIZER, OS_UNFAIR_LOCK_INIT, ATOMIC_INIT(false)}},  \
+  {{{LOCK_PROF_DATA_INITIALIZER, ATOMIC_INIT(false), OS_UNFAIR_LOCK_INIT}},  \
       WITNESS_INITIALIZER("mutex", WITNESS_RANK_OMIT)}
 #  endif
 #elif (defined(JEMALLOC_MUTEX_INIT_CB))
 #  if (defined(JEMALLOC_DEBUG))
 #     define MALLOC_MUTEX_INITIALIZER					\
-      {{{LOCK_PROF_DATA_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, NULL, ATOMIC_INIT(false)}},	\
+      {{{LOCK_PROF_DATA_INITIALIZER, ATOMIC_INIT(false), PTHREAD_MUTEX_INITIALIZER, NULL}},	\
            WITNESS_INITIALIZER("mutex", WITNESS_RANK_OMIT), 0}
 #  else
 #     define MALLOC_MUTEX_INITIALIZER					\
-      {{{LOCK_PROF_DATA_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, NULL, ATOMIC_INIT(false)}},	\
+      {{{LOCK_PROF_DATA_INITIALIZER, ATOMIC_INIT(false), PTHREAD_MUTEX_INITIALIZER, NULL}},	\
            WITNESS_INITIALIZER("mutex", WITNESS_RANK_OMIT)}
 #  endif
 
@@ -121,11 +122,11 @@ struct malloc_mutex_s {
 #    define MALLOC_MUTEX_TYPE PTHREAD_MUTEX_DEFAULT
 #  if defined(JEMALLOC_DEBUG)
 #    define MALLOC_MUTEX_INITIALIZER					\
-     {{{LOCK_PROF_DATA_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, ATOMIC_INIT(false)}}, \
+     {{{LOCK_PROF_DATA_INITIALIZER, ATOMIC_INIT(false), PTHREAD_MUTEX_INITIALIZER}}, \
            WITNESS_INITIALIZER("mutex", WITNESS_RANK_OMIT), 0}
 #  else
 #    define MALLOC_MUTEX_INITIALIZER                          \
-     {{{LOCK_PROF_DATA_INITIALIZER, PTHREAD_MUTEX_INITIALIZER, ATOMIC_INIT(false)}},	\
+     {{{LOCK_PROF_DATA_INITIALIZER, ATOMIC_INIT(false), PTHREAD_MUTEX_INITIALIZER}},	\
       WITNESS_INITIALIZER("mutex", WITNESS_RANK_OMIT)}
 #  endif
 #endif

include/jemalloc/internal/tcache_externs.h

@@ -26,7 +26,7 @@ extern unsigned opt_lg_tcache_flush_large_div;
  * it should not be changed on the fly.  To change the number of tcache bins
  * in use, refer to tcache_nbins of each tcache.
  */
-extern unsigned	global_do_not_change_nbins;
+extern unsigned	global_do_not_change_tcache_nbins;
 
 /*
  * Maximum cached size class.  Same as above, this is only used during threads
@@ -55,6 +55,11 @@ void tcache_bin_flush_large(tsd_t *tsd, tcache_t *tcache,
     cache_bin_t *cache_bin, szind_t binind, unsigned rem);
 void tcache_bin_flush_stashed(tsd_t *tsd, tcache_t *tcache,
     cache_bin_t *cache_bin, szind_t binind, bool is_small);
+bool tcache_bin_info_default_init(const char *bin_settings_segment_cur,
+    size_t len_left);
+bool tcache_bins_ncached_max_write(tsd_t *tsd, char *settings, size_t len);
+bool tcache_bin_ncached_max_read(tsd_t *tsd, size_t bin_size,
+    cache_bin_sz_t *ncached_max);
 void tcache_arena_reassociate(tsdn_t *tsdn, tcache_slow_t *tcache_slow,
     tcache_t *tcache, arena_t *arena);
 tcache_t *tcache_create_explicit(tsd_t *tsd);

include/jemalloc/internal/tcache_inlines.h

@@ -46,7 +46,7 @@ tcache_bin_settings_backup(tcache_t *tcache,
     cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX]) {
 	for (unsigned i = 0; i < TCACHE_NBINS_MAX; i++) {
 		cache_bin_info_init(&tcache_bin_info[i],
-		    tcache->bins[i].bin_info.ncached_max);
+		    cache_bin_ncached_max_get_unsafe(&tcache->bins[i]));
 	}
 }
 
@@ -54,6 +54,7 @@ JEMALLOC_ALWAYS_INLINE bool
 tcache_bin_disabled(szind_t ind, cache_bin_t *bin,
     tcache_slow_t *tcache_slow) {
 	assert(bin != NULL);
+	assert(ind < TCACHE_NBINS_MAX);
 	bool disabled = cache_bin_disabled(bin);
 
 	/*
@@ -66,7 +67,7 @@ tcache_bin_disabled(szind_t ind, cache_bin_t *bin,
 	 * ind < nbins and ncached_max > 0.
 	 */
 	unsigned nbins = tcache_nbins_get(tcache_slow);
-	cache_bin_sz_t ncached_max = bin->bin_info.ncached_max;
+	cache_bin_sz_t ncached_max = cache_bin_ncached_max_get_unsafe(bin);
 	if (ind >= nbins) {
 		assert(disabled);
 	} else {
@@ -199,8 +200,7 @@ tcache_dalloc_small(tsd_t *tsd, tcache_t *tcache, void *ptr, szind_t binind,
 			arena_dalloc_small(tsd_tsdn(tsd), ptr);
 			return;
 		}
-		cache_bin_sz_t max = cache_bin_info_ncached_max_get(
+		cache_bin_sz_t max = cache_bin_ncached_max_get(bin);
-		    bin, &bin->bin_info);
 		unsigned remain = max >> opt_lg_tcache_flush_small_div;
 		tcache_bin_flush_small(tsd, tcache, bin, binind, remain);
 		bool ret = cache_bin_dalloc_easy(bin, ptr);
@@ -215,11 +215,13 @@ tcache_dalloc_large(tsd_t *tsd, tcache_t *tcache, void *ptr, szind_t binind,
 	assert(tcache_salloc(tsd_tsdn(tsd), ptr) > SC_SMALL_MAXCLASS);
 	assert(tcache_salloc(tsd_tsdn(tsd), ptr) <=
 	    tcache_max_get(tcache->tcache_slow));
+	assert(!tcache_bin_disabled(binind, &tcache->bins[binind],
+	    tcache->tcache_slow));
 
 	cache_bin_t *bin = &tcache->bins[binind];
 	if (unlikely(!cache_bin_dalloc_easy(bin, ptr))) {
-		unsigned remain = cache_bin_info_ncached_max_get(
+		unsigned remain = cache_bin_ncached_max_get(bin) >>
-		    bin, &bin->bin_info) >> opt_lg_tcache_flush_large_div;
+		    opt_lg_tcache_flush_large_div;
 		tcache_bin_flush_large(tsd, tcache, bin, binind, remain);
 		bool ret = cache_bin_dalloc_easy(bin, ptr);
 		assert(ret);

include/jemalloc/internal/tcache_types.h

@@ -10,7 +10,7 @@ typedef struct tcaches_s tcaches_t;
 
 /* Used in TSD static initializer only. Real init in tsd_tcache_data_init(). */
 #define TCACHE_ZERO_INITIALIZER {0}
-#define TCACHE_SLOW_ZERO_INITIALIZER {0}
+#define TCACHE_SLOW_ZERO_INITIALIZER {{0}}
 
 /* Used in TSD static initializer only. Will be initialized to opt_tcache. */
 #define TCACHE_ENABLED_ZERO_INITIALIZER false

include/jemalloc/internal/util.h

@@ -130,4 +130,12 @@ util_prefetch_write_range(void *ptr, size_t sz) {
 
 #undef UTIL_INLINE
 
+/*
+ * Reads the settings in the following format:
+ * key1-key2:value|key3-key4:value|...
+ * Note it does not handle the ending '\0'.
+ */
+bool
+multi_setting_parse_next(const char **setting_segment_cur, size_t *len_left,
+    size_t *key_start, size_t *key_end, size_t *value);
 #endif /* JEMALLOC_INTERNAL_UTIL_H */

msvc/projects/vc2015/jemalloc/jemalloc.vcxproj

@@ -96,6 +96,7 @@
     <ClCompile Include="..\..\..\..\src\thread_event.c" />
     <ClCompile Include="..\..\..\..\src\ticker.c" />
     <ClCompile Include="..\..\..\..\src\tsd.c" />
+    <ClCompile Include="..\..\..\..\src\util.c" />
     <ClCompile Include="..\..\..\..\src\witness.c" />
   </ItemGroup>
   <PropertyGroup Label="Globals">

msvc/projects/vc2015/jemalloc/jemalloc.vcxproj.filters

@@ -166,6 +166,9 @@
     <ClCompile Include="..\..\..\..\src\tsd.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\..\..\src\util.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\..\..\src\witness.c">
       <Filter>Source Files</Filter>
     </ClCompile>

msvc/projects/vc2017/jemalloc/jemalloc.vcxproj

@@ -96,6 +96,7 @@
     <ClCompile Include="..\..\..\..\src\thread_event.c" />
     <ClCompile Include="..\..\..\..\src\ticker.c" />
     <ClCompile Include="..\..\..\..\src\tsd.c" />
+    <ClCompile Include="..\..\..\..\src\util.c" />
     <ClCompile Include="..\..\..\..\src\witness.c" />
   </ItemGroup>
   <PropertyGroup Label="Globals">

msvc/projects/vc2017/jemalloc/jemalloc.vcxproj.filters

@@ -166,6 +166,9 @@
     <ClCompile Include="..\..\..\..\src\tsd.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\..\..\src\util.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\..\..\src\witness.c">
       <Filter>Source Files</Filter>
     </ClCompile>

msvc/projects/vc2019/jemalloc/jemalloc.vcxproj

@@ -96,6 +96,7 @@
     <ClCompile Include="..\..\..\..\src\thread_event.c" />
     <ClCompile Include="..\..\..\..\src\ticker.c" />
     <ClCompile Include="..\..\..\..\src\tsd.c" />
+    <ClCompile Include="..\..\..\..\src\util.c" />
     <ClCompile Include="..\..\..\..\src\witness.c" />
   </ItemGroup>
   <PropertyGroup Label="Globals">

msvc/projects/vc2019/jemalloc/jemalloc.vcxproj.filters

@@ -166,6 +166,9 @@
     <ClCompile Include="..\..\..\..\src\tsd.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\..\..\src\util.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\..\..\src\witness.c">
       <Filter>Source Files</Filter>
     </ClCompile>

msvc/projects/vc2022/jemalloc/jemalloc.vcxproj

@@ -96,6 +96,7 @@
     <ClCompile Include="..\..\..\..\src\thread_event.c" />
     <ClCompile Include="..\..\..\..\src\ticker.c" />
     <ClCompile Include="..\..\..\..\src\tsd.c" />
+    <ClCompile Include="..\..\..\..\src\util.c" />
     <ClCompile Include="..\..\..\..\src\witness.c" />
   </ItemGroup>
   <PropertyGroup Label="Globals">

msvc/projects/vc2022/jemalloc/jemalloc.vcxproj.filters

@@ -166,6 +166,9 @@
     <ClCompile Include="..\..\..\..\src\tsd.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\..\..\src\util.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\..\..\src\witness.c">
       <Filter>Source Files</Filter>
     </ClCompile>

src/arena.c

@@ -168,8 +168,7 @@ arena_stats_merge(tsdn_t *tsdn, arena_t *arena, unsigned *nthreads,
 			}
 
 			cache_bin_sz_t ncached, nstashed;
-			cache_bin_nitems_get_remote(cache_bin,
+			cache_bin_nitems_get_remote(cache_bin, &ncached, &nstashed);
-			    &cache_bin->bin_info, &ncached, &nstashed);
 			astats->tcache_bytes += ncached * sz_index2size(i);
 			astats->tcache_stashed_bytes += nstashed *
 			    sz_index2size(i);
@@ -1020,15 +1019,14 @@ arena_bin_choose(tsdn_t *tsdn, arena_t *arena, szind_t binind,
 
 void
 arena_cache_bin_fill_small(tsdn_t *tsdn, arena_t *arena,
-    cache_bin_t *cache_bin, cache_bin_info_t *cache_bin_info, szind_t binind,
+    cache_bin_t *cache_bin, szind_t binind, const unsigned nfill) {
-    const unsigned nfill) {
+	assert(cache_bin_ncached_get_local(cache_bin) == 0);
-	assert(cache_bin_ncached_get_local(cache_bin, cache_bin_info) == 0);
+	assert(nfill != 0);
 
 	const bin_info_t *bin_info = &bin_infos[binind];
 
 	CACHE_BIN_PTR_ARRAY_DECLARE(ptrs, nfill);
-	cache_bin_init_ptr_array_for_fill(cache_bin, cache_bin_info, &ptrs,
+	cache_bin_init_ptr_array_for_fill(cache_bin, &ptrs, nfill);
-	    nfill);
 	/*
 	 * Bin-local resources are used first: 1) bin->slabcur, and 2) nonfull
 	 * slabs.  After both are exhausted, new slabs will be allocated through
@@ -1142,7 +1140,7 @@ label_refill:
 		fresh_slab = NULL;
 	}
 
-	cache_bin_finish_fill(cache_bin, cache_bin_info, &ptrs, filled);
+	cache_bin_finish_fill(cache_bin, &ptrs, filled);
 	arena_decay_tick(tsdn, arena);
 }
 
@@ -1665,11 +1663,16 @@ arena_new(tsdn_t *tsdn, unsigned ind, const arena_config_t *config) {
 		}
 	}
 
-	size_t arena_size = sizeof(arena_t) + sizeof(bin_t) * nbins_total;
+	size_t arena_size = ALIGNMENT_CEILING(sizeof(arena_t), CACHELINE) +
+	    sizeof(bin_t) * nbins_total;
 	arena = (arena_t *)base_alloc(tsdn, base, arena_size, CACHELINE);
 	if (arena == NULL) {
 		goto label_error;
 	}
+	JEMALLOC_SUPPRESS_WARN_ON_USAGE(
+	assert((uintptr_t)&arena->all_bins[nbins_total -1] + sizeof(bin_t) <=
+	    (uintptr_t)arena + arena_size);
+	)
 
 	atomic_store_u(&arena->nthreads[0], 0, ATOMIC_RELAXED);
 	atomic_store_u(&arena->nthreads[1], 0, ATOMIC_RELAXED);

src/cache_bin.c

@@ -10,6 +10,7 @@ const uintptr_t disabled_bin = JUNK_ADDR;
 void
 cache_bin_info_init(cache_bin_info_t *info,
     cache_bin_sz_t ncached_max) {
+	assert(ncached_max <= CACHE_BIN_NCACHED_MAX);
 	size_t stack_size = (size_t)ncached_max * sizeof(void *);
 	assert(stack_size < ((size_t)1 << (sizeof(cache_bin_sz_t) * 8)));
 	info->ncached_max = (cache_bin_sz_t)ncached_max;
@@ -27,7 +28,7 @@ cache_bin_stack_use_thp(void) {
 }
 
 void
-cache_bin_info_compute_alloc(cache_bin_info_t *infos, szind_t ninfos,
+cache_bin_info_compute_alloc(const cache_bin_info_t *infos, szind_t ninfos,
     size_t *size, size_t *alignment) {
 	/* For the total bin stack region (per tcache), reserve 2 more slots so
 	 * that
@@ -50,7 +51,7 @@ cache_bin_info_compute_alloc(cache_bin_info_t *infos, szind_t ninfos,
 }
 
 void
-cache_bin_preincrement(cache_bin_info_t *infos, szind_t ninfos, void *alloc,
+cache_bin_preincrement(const cache_bin_info_t *infos, szind_t ninfos, void *alloc,
     size_t *cur_offset) {
 	if (config_debug) {
 		size_t computed_size;
@@ -75,7 +76,7 @@ cache_bin_postincrement(void *alloc, size_t *cur_offset) {
 }
 
 void
-cache_bin_init(cache_bin_t *bin, cache_bin_info_t *info, void *alloc,
+cache_bin_init(cache_bin_t *bin, const cache_bin_info_t *info, void *alloc,
     size_t *cur_offset) {
 	/*
 	 * The full_position points to the lowest available space.  Allocations
@@ -99,7 +100,7 @@ cache_bin_init(cache_bin_t *bin, cache_bin_info_t *info, void *alloc,
 	    bin->low_bits_full, (uint16_t)(uintptr_t)bin->stack_head);
 	assert(free_spots == bin_stack_size);
 	if (!cache_bin_disabled(bin)) {
-		assert(cache_bin_ncached_get_local(bin, &bin->bin_info) == 0);
+		assert(cache_bin_ncached_get_local(bin) == 0);
 	}
 	assert(cache_bin_empty_position_get(bin) == empty_position);
 

src/ctl.c

@@ -68,6 +68,8 @@ CTL_PROTO(max_background_threads)
 CTL_PROTO(thread_tcache_enabled)
 CTL_PROTO(thread_tcache_max)
 CTL_PROTO(thread_tcache_flush)
+CTL_PROTO(thread_tcache_ncached_max_write)
+CTL_PROTO(thread_tcache_ncached_max_read_sizeclass)
 CTL_PROTO(thread_peak_read)
 CTL_PROTO(thread_peak_reset)
 CTL_PROTO(thread_prof_name)
@@ -374,10 +376,17 @@ CTL_PROTO(stats_mutexes_reset)
  */
 #define INDEX(i)	{false},	i##_index
 
+static const ctl_named_node_t	thread_tcache_ncached_max_node[] = {
+	{NAME("read_sizeclass"),
+	    CTL(thread_tcache_ncached_max_read_sizeclass)},
+	{NAME("write"),		CTL(thread_tcache_ncached_max_write)}
+};
+
 static const ctl_named_node_t	thread_tcache_node[] = {
 	{NAME("enabled"),	CTL(thread_tcache_enabled)},
 	{NAME("max"),		CTL(thread_tcache_max)},
-	{NAME("flush"),		CTL(thread_tcache_flush)}
+	{NAME("flush"),		CTL(thread_tcache_flush)},
+	{NAME("ncached_max"),	CHILD(named, thread_tcache_ncached_max)}
 };
 
 static const ctl_named_node_t	thread_peak_node[] = {
@@ -2282,6 +2291,78 @@ label_return:
 
 CTL_RO_NL_GEN(thread_allocated, tsd_thread_allocated_get(tsd), uint64_t)
 CTL_RO_NL_GEN(thread_allocatedp, tsd_thread_allocatedp_get(tsd), uint64_t *)
+
+static int
+thread_tcache_ncached_max_read_sizeclass_ctl(tsd_t *tsd, const size_t *mib,
+    size_t miblen, void *oldp, size_t *oldlenp, void *newp,
+    size_t newlen) {
+	int ret;
+	size_t bin_size = 0;
+
+	/* Read the bin size from newp. */
+	if (newp == NULL) {
+		ret = EINVAL;
+		goto label_return;
+	}
+	WRITE(bin_size, size_t);
+
+	cache_bin_sz_t ncached_max = 0;
+	if (tcache_bin_ncached_max_read(tsd, bin_size, &ncached_max)) {
+		ret = EINVAL;
+		goto label_return;
+	}
+	size_t result = (size_t)ncached_max;
+	READ(result, size_t);
+	ret = 0;
+label_return:
+	return ret;
+}
+
+static int
+thread_tcache_ncached_max_write_ctl(tsd_t *tsd, const size_t *mib,
+    size_t miblen, void *oldp, size_t *oldlenp, void *newp,
+    size_t newlen) {
+	int ret;
+	WRITEONLY();
+	if (newp != NULL) {
+		if (!tcache_available(tsd)) {
+			ret = ENOENT;
+			goto label_return;
+		}
+		char *settings = NULL;
+		WRITE(settings, char *);
+		if (settings == NULL) {
+			ret = EINVAL;
+			goto label_return;
+		}
+		/* Get the length of the setting string safely. */
+		char *end = (char *)memchr(settings, '\0',
+		    CTL_MULTI_SETTING_MAX_LEN);
+		if (end == NULL) {
+			ret = EINVAL;
+			goto label_return;
+		}
+		/*
+		 * Exclude the last '\0' for len since it is not handled by
+		 * multi_setting_parse_next.
+		 */
+		size_t len = (uintptr_t)end - (uintptr_t)settings;
+		if (len == 0) {
+			ret = 0;
+			goto label_return;
+		}
+
+		if (tcache_bins_ncached_max_write(tsd, settings, len)) {
+			ret = EINVAL;
+			goto label_return;
+		}
+	}
+
+	ret = 0;
+label_return:
+	return ret;
+}
+
 CTL_RO_NL_GEN(thread_deallocated, tsd_thread_deallocated_get(tsd), uint64_t)
 CTL_RO_NL_GEN(thread_deallocatedp, tsd_thread_deallocatedp_get(tsd), uint64_t *)
 
@@ -3155,7 +3236,7 @@ CTL_RO_NL_GEN(arenas_quantum, QUANTUM, size_t)
 CTL_RO_NL_GEN(arenas_page, PAGE, size_t)
 CTL_RO_NL_GEN(arenas_tcache_max, global_do_not_change_tcache_maxclass, size_t)
 CTL_RO_NL_GEN(arenas_nbins, SC_NBINS, unsigned)
-CTL_RO_NL_GEN(arenas_nhbins, global_do_not_change_nbins, unsigned)
+CTL_RO_NL_GEN(arenas_nhbins, global_do_not_change_tcache_nbins, unsigned)
 CTL_RO_NL_GEN(arenas_bin_i_size, bin_infos[mib[2]].reg_size, size_t)
 CTL_RO_NL_GEN(arenas_bin_i_nregs, bin_infos[mib[2]].nregs, uint32_t)
 CTL_RO_NL_GEN(arenas_bin_i_slab_size, bin_infos[mib[2]].slab_size, size_t)

src/jemalloc.c

@@ -821,50 +821,6 @@ init_opt_stats_opts(const char *v, size_t vlen, char *dest) {
 	assert(opts_len == strlen(dest));
 }
 
-/* Reads the next size pair in a multi-sized option. */
-static bool
-malloc_conf_multi_sizes_next(const char **slab_size_segment_cur,
-    size_t *vlen_left, size_t *slab_start, size_t *slab_end, size_t *new_size) {
-	const char *cur = *slab_size_segment_cur;
-	char *end;
-	uintmax_t um;
-
-	set_errno(0);
-
-	/* First number, then '-' */
-	um = malloc_strtoumax(cur, &end, 0);
-	if (get_errno() != 0 || *end != '-') {
-		return true;
-	}
-	*slab_start = (size_t)um;
-	cur = end + 1;
-
-	/* Second number, then ':' */
-	um = malloc_strtoumax(cur, &end, 0);
-	if (get_errno() != 0 || *end != ':') {
-		return true;
-	}
-	*slab_end = (size_t)um;
-	cur = end + 1;
-
-	/* Last number */
-	um = malloc_strtoumax(cur, &end, 0);
-	if (get_errno() != 0) {
-		return true;
-	}
-	*new_size = (size_t)um;
-
-	/* Consume the separator if there is one. */
-	if (*end == '|') {
-		end++;
-	}
-
-	*vlen_left -= end - *slab_size_segment_cur;
-	*slab_size_segment_cur = end;
-
-	return false;
-}
-
 static void
 malloc_conf_format_error(const char *msg, const char *begin, const char *end) {
 	size_t len = end - begin + 1;
@@ -1351,7 +1307,7 @@ malloc_conf_init_helper(sc_data_t *sc_data, unsigned bin_shard_sizes[SC_NBINS],
 					size_t size_start;
 					size_t size_end;
 					size_t nshards;
-					bool err = malloc_conf_multi_sizes_next(
+					bool err = multi_setting_parse_next(
 					    &bin_shards_segment_cur, &vlen_left,
 					    &size_start, &size_end, &nshards);
 					if (err || bin_update_shard_size(
@@ -1366,6 +1322,16 @@ malloc_conf_init_helper(sc_data_t *sc_data, unsigned bin_shard_sizes[SC_NBINS],
 				} while (vlen_left > 0);
 				CONF_CONTINUE;
 			}
+			if (CONF_MATCH("tcache_ncached_max")) {
+				bool err = tcache_bin_info_default_init(
+				    v, vlen);
+				if (err) {
+					CONF_ERROR("Invalid settings for "
+					    "tcache_ncached_max", k, klen, v,
+					    vlen);
+				}
+				CONF_CONTINUE;
+			}
 			CONF_HANDLE_INT64_T(opt_mutex_max_spin,
 			    "mutex_max_spin", -1, INT64_MAX, CONF_CHECK_MIN,
 			    CONF_DONT_CHECK_MAX, false);
@@ -1613,7 +1579,7 @@ malloc_conf_init_helper(sc_data_t *sc_data, unsigned bin_shard_sizes[SC_NBINS],
 					size_t slab_start;
 					size_t slab_end;
 					size_t pgs;
-					err = malloc_conf_multi_sizes_next(
+					err = multi_setting_parse_next(
 					    &slab_size_segment_cur,
 					    &vlen_left, &slab_start, &slab_end,
 					    &pgs);
@@ -4140,6 +4106,7 @@ batch_alloc(void **ptrs, size_t num, size_t size, int flags) {
 		tcache_t *tcache = tcache_get_from_ind(tsd, tcache_ind,
 		    /* slow */ true, /* is_alloc */ true);
 		if (likely(tcache != NULL &&
+		    ind < tcache_nbins_get(tcache->tcache_slow) &&
 		    !tcache_bin_disabled(ind, &tcache->bins[ind],
 		    tcache->tcache_slow)) && progress < batch) {
 			if (bin == NULL) {

src/tcache.c

@@ -63,7 +63,7 @@ unsigned opt_lg_tcache_flush_large_div = 1;
  * is only used to initialize tcache_nbins in the per-thread tcache.
  * Directly modifying it will not affect threads already launched.
  */
-unsigned		global_do_not_change_nbins;
+unsigned		global_do_not_change_tcache_nbins;
 /*
  * Max size class to be cached (can be small or large). This value is only used
  * to initialize tcache_max in the per-thread tcache.   Directly modifying it
@@ -71,6 +71,18 @@ unsigned		global_do_not_change_nbins;
  */
 size_t			global_do_not_change_tcache_maxclass;
 
+/*
+ * Default bin info for each bin.  Will be initialized in malloc_conf_init
+ * and tcache_boot and should not be modified after that.
+ */
+static cache_bin_info_t opt_tcache_ncached_max[TCACHE_NBINS_MAX] = {{0}};
+/*
+ * Marks whether a bin's info is set already.  This is used in
+ * tcache_bin_info_compute to avoid overwriting ncached_max specified by
+ * malloc_conf.  It should be set only when parsing malloc_conf.
+ */
+static bool opt_tcache_ncached_max_set[TCACHE_NBINS_MAX] = {0};
+
 tcaches_t		*tcaches;
 
 /* Index of first element within tcaches that has never been used. */
@@ -130,10 +142,8 @@ tcache_gc_small(tsd_t *tsd, tcache_slow_t *tcache_slow, tcache_t *tcache,
 
 	cache_bin_t *cache_bin = &tcache->bins[szind];
 	assert(!tcache_bin_disabled(szind, cache_bin, tcache->tcache_slow));
-	cache_bin_sz_t ncached = cache_bin_ncached_get_local(cache_bin,
+	cache_bin_sz_t ncached = cache_bin_ncached_get_local(cache_bin);
-	    &cache_bin->bin_info);
+	cache_bin_sz_t low_water = cache_bin_low_water_get(cache_bin);
-	cache_bin_sz_t low_water = cache_bin_low_water_get(cache_bin,
-	    &cache_bin->bin_info);
 	assert(!tcache_slow->bin_refilled[szind]);
 
 	size_t nflush = low_water - (low_water >> 2);
@@ -156,8 +166,8 @@ tcache_gc_small(tsd_t *tsd, tcache_slow_t *tcache_slow, tcache_t *tcache,
 	 * Reduce fill count by 2X.  Limit lg_fill_div such that
 	 * the fill count is always at least 1.
 	 */
-	if ((cache_bin_info_ncached_max_get(cache_bin, &cache_bin->bin_info)
+	if ((cache_bin_ncached_max_get(cache_bin) >>
-	    >> (tcache_slow->lg_fill_div[szind] + 1)) >= 1) {
+	    (tcache_slow->lg_fill_div[szind] + 1)) >= 1) {
 		tcache_slow->lg_fill_div[szind]++;
 	}
 }
@@ -169,10 +179,8 @@ tcache_gc_large(tsd_t *tsd, tcache_slow_t *tcache_slow, tcache_t *tcache,
 	assert(szind >= SC_NBINS);
 	cache_bin_t *cache_bin = &tcache->bins[szind];
 	assert(!tcache_bin_disabled(szind, cache_bin, tcache->tcache_slow));
-	cache_bin_sz_t ncached = cache_bin_ncached_get_local(cache_bin,
+	cache_bin_sz_t ncached = cache_bin_ncached_get_local(cache_bin);
-	    &cache_bin->bin_info);
+	cache_bin_sz_t low_water = cache_bin_low_water_get(cache_bin);
-	cache_bin_sz_t low_water = cache_bin_low_water_get(cache_bin,
-	    &cache_bin->bin_info);
 	tcache_bin_flush_large(tsd, tcache, cache_bin, szind,
 	    (unsigned)(ncached - low_water + (low_water >> 2)));
 }
@@ -193,10 +201,8 @@ tcache_event(tsd_t *tsd) {
 		goto label_done;
 	}
 
-	tcache_bin_flush_stashed(tsd, tcache, cache_bin, szind,
+	tcache_bin_flush_stashed(tsd, tcache, cache_bin, szind, is_small);
-	    is_small);
+	cache_bin_sz_t low_water = cache_bin_low_water_get(cache_bin);
-	cache_bin_sz_t low_water = cache_bin_low_water_get(cache_bin,
-	    &cache_bin->bin_info);
 	if (low_water > 0) {
 		if (is_small) {
 			tcache_gc_small(tsd, tcache_slow, tcache, szind);
@@ -244,10 +250,12 @@ tcache_alloc_small_hard(tsdn_t *tsdn, arena_t *arena,
 
 	assert(tcache_slow->arena != NULL);
 	assert(!tcache_bin_disabled(binind, cache_bin, tcache_slow));
-	unsigned nfill = cache_bin_info_ncached_max_get(cache_bin,
+	unsigned nfill = cache_bin_ncached_max_get(cache_bin)
-	    &cache_bin->bin_info) >> tcache_slow->lg_fill_div[binind];
+	    >> tcache_slow->lg_fill_div[binind];
-	arena_cache_bin_fill_small(tsdn, arena, cache_bin,
+	if (nfill == 0) {
-	    &cache_bin->bin_info, binind, nfill);
+		nfill = 1;
+	}
+	arena_cache_bin_fill_small(tsdn, arena, cache_bin, binind, nfill);
 	tcache_slow->bin_refilled[binind] = true;
 	ret = cache_bin_alloc(cache_bin, tcache_success);
 
@@ -519,20 +527,17 @@ tcache_bin_flush_bottom(tsd_t *tsd, tcache_t *tcache, cache_bin_t *cache_bin,
 	assert(!tcache_bin_disabled(binind, cache_bin, tcache->tcache_slow));
 	tcache_bin_flush_stashed(tsd, tcache, cache_bin, binind, small);
 
-	cache_bin_sz_t ncached = cache_bin_ncached_get_local(cache_bin,
+	cache_bin_sz_t ncached = cache_bin_ncached_get_local(cache_bin);
-	    &cache_bin->bin_info);
 	assert((cache_bin_sz_t)rem <= ncached);
 	unsigned nflush = ncached - rem;
 
 	CACHE_BIN_PTR_ARRAY_DECLARE(ptrs, nflush);
-	cache_bin_init_ptr_array_for_flush(cache_bin, &cache_bin->bin_info,
+	cache_bin_init_ptr_array_for_flush(cache_bin, &ptrs, nflush);
-	    &ptrs, nflush);
 
 	tcache_bin_flush_impl(tsd, tcache, cache_bin, binind, &ptrs, nflush,
 	    small);
 
-	cache_bin_finish_flush(cache_bin, &cache_bin->bin_info, &ptrs,
+	cache_bin_finish_flush(cache_bin, &ptrs, ncached - rem);
-	    ncached - rem);
 }
 
 void
@@ -561,36 +566,65 @@ void
 tcache_bin_flush_stashed(tsd_t *tsd, tcache_t *tcache, cache_bin_t *cache_bin,
     szind_t binind, bool is_small) {
 	assert(!tcache_bin_disabled(binind, cache_bin, tcache->tcache_slow));
-	cache_bin_info_t *info = &cache_bin->bin_info;
 	/*
 	 * The two below are for assertion only.  The content of original cached
 	 * items remain unchanged -- the stashed items reside on the other end
 	 * of the stack.  Checking the stack head and ncached to verify.
 	 */
 	void *head_content = *cache_bin->stack_head;
-	cache_bin_sz_t orig_cached = cache_bin_ncached_get_local(cache_bin,
+	cache_bin_sz_t orig_cached = cache_bin_ncached_get_local(cache_bin);
-	    info);
 
-	cache_bin_sz_t nstashed = cache_bin_nstashed_get_local(cache_bin, info);
+	cache_bin_sz_t nstashed = cache_bin_nstashed_get_local(cache_bin);
-	assert(orig_cached + nstashed <=
+	assert(orig_cached + nstashed <= cache_bin_ncached_max_get(cache_bin));
-	    cache_bin_info_ncached_max_get(cache_bin, info));
 	if (nstashed == 0) {
 		return;
 	}
 
 	CACHE_BIN_PTR_ARRAY_DECLARE(ptrs, nstashed);
-	cache_bin_init_ptr_array_for_stashed(cache_bin, binind, info, &ptrs,
+	cache_bin_init_ptr_array_for_stashed(cache_bin, binind, &ptrs,
 	    nstashed);
 	san_check_stashed_ptrs(ptrs.ptr, nstashed, sz_index2size(binind));
 	tcache_bin_flush_impl(tsd, tcache, cache_bin, binind, &ptrs, nstashed,
 	    is_small);
-	cache_bin_finish_flush_stashed(cache_bin, info);
+	cache_bin_finish_flush_stashed(cache_bin);
 
-	assert(cache_bin_nstashed_get_local(cache_bin, info) == 0);
+	assert(cache_bin_nstashed_get_local(cache_bin) == 0);
-	assert(cache_bin_ncached_get_local(cache_bin, info) == orig_cached);
+	assert(cache_bin_ncached_get_local(cache_bin) == orig_cached);
 	assert(head_content == *cache_bin->stack_head);
 }
 
+JET_EXTERN bool
+tcache_get_default_ncached_max_set(szind_t ind) {
+	return opt_tcache_ncached_max_set[ind];
+}
+
+JET_EXTERN const cache_bin_info_t *
+tcache_get_default_ncached_max(void) {
+	return opt_tcache_ncached_max;
+}
+
+bool
+tcache_bin_ncached_max_read(tsd_t *tsd, size_t bin_size,
+    cache_bin_sz_t *ncached_max) {
+	if (bin_size > TCACHE_MAXCLASS_LIMIT) {
+		return true;
+	}
+
+	if (!tcache_available(tsd)) {
+		*ncached_max = 0;
+		return false;
+	}
+
+	tcache_t *tcache = tsd_tcachep_get(tsd);
+	assert(tcache != NULL);
+	szind_t bin_ind = sz_size2index(bin_size);
+
+	cache_bin_t *bin = &tcache->bins[bin_ind];
+	*ncached_max = tcache_bin_disabled(bin_ind, bin, tcache->tcache_slow) ?
+	    0: cache_bin_ncached_max_get(bin);
+	return false;
+}
+
 void
 tcache_arena_associate(tsdn_t *tsdn, tcache_slow_t *tcache_slow,
     tcache_t *tcache, arena_t *arena) {
@@ -651,13 +685,13 @@ static void
 tcache_default_settings_init(tcache_slow_t *tcache_slow) {
 	assert(tcache_slow != NULL);
 	assert(global_do_not_change_tcache_maxclass != 0);
-	assert(global_do_not_change_nbins != 0);
+	assert(global_do_not_change_tcache_nbins != 0);
-	tcache_slow->tcache_nbins = global_do_not_change_nbins;
+	tcache_slow->tcache_nbins = global_do_not_change_tcache_nbins;
 }
 
 static void
 tcache_init(tsd_t *tsd, tcache_slow_t *tcache_slow, tcache_t *tcache,
-    void *mem, cache_bin_info_t *tcache_bin_info) {
+    void *mem, const cache_bin_info_t *tcache_bin_info) {
 	tcache->tcache_slow = tcache_slow;
 	tcache_slow->tcache = tcache;
 
@@ -772,14 +806,16 @@ tcache_ncached_max_compute(szind_t szind) {
 	}
 }
 
-static void
+JET_EXTERN void
 tcache_bin_info_compute(cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX]) {
 	/*
 	 * Compute the values for each bin, but for bins with indices larger
 	 * than tcache_nbins, no items will be cached.
 	 */
 	for (szind_t i = 0; i < TCACHE_NBINS_MAX; i++) {
-		unsigned ncached_max = tcache_ncached_max_compute(i);
+		unsigned ncached_max = tcache_get_default_ncached_max_set(i) ?
+		    (unsigned)tcache_get_default_ncached_max()[i].ncached_max:
+		    tcache_ncached_max_compute(i);
 		assert(ncached_max <= CACHE_BIN_NCACHED_MAX);
 		cache_bin_info_init(&tcache_bin_info[i], ncached_max);
 	}
@@ -787,7 +823,7 @@ tcache_bin_info_compute(cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX]) {
 
 static bool
 tsd_tcache_data_init_impl(tsd_t *tsd, arena_t *arena,
-    cache_bin_info_t *tcache_bin_info) {
+    const cache_bin_info_t *tcache_bin_info) {
 	tcache_slow_t *tcache_slow = tsd_tcache_slowp_get_unsafe(tsd);
 	tcache_t *tcache = tsd_tcachep_get_unsafe(tsd);
 
@@ -841,20 +877,11 @@ tsd_tcache_data_init_impl(tsd_t *tsd, arena_t *arena,
 	return false;
 }
 
-static bool
-tsd_tcache_data_init_with_bin_settings(tsd_t *tsd, arena_t *arena,
-    cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX]) {
-	assert(tcache_bin_info != NULL);
-	return tsd_tcache_data_init_impl(tsd, arena, tcache_bin_info);
-}
-
 /* Initialize auto tcache (embedded in TSD). */
 static bool
-tsd_tcache_data_init(tsd_t *tsd, arena_t *arena) {
+tsd_tcache_data_init(tsd_t *tsd, arena_t *arena,
-	/* Takes 146B stack space. */
+    const cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX]) {
-	cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX] = {{0}};
+	assert(tcache_bin_info != NULL);
-	tcache_bin_info_compute(tcache_bin_info);
-
 	return tsd_tcache_data_init_impl(tsd, arena, tcache_bin_info);
 }
 
@@ -866,12 +893,10 @@ tcache_create_explicit(tsd_t *tsd) {
 	 * the beginning of the whole allocation (for freeing).  The makes sure
 	 * the cache bins have the requested alignment.
 	 */
-	unsigned tcache_nbins = global_do_not_change_nbins;
+	unsigned tcache_nbins = global_do_not_change_tcache_nbins;
 	size_t tcache_size, alignment;
-	cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX] = {{0}};
+	cache_bin_info_compute_alloc(tcache_get_default_ncached_max(),
-	tcache_bin_info_compute(tcache_bin_info);
+	    tcache_nbins, &tcache_size, &alignment);
-	cache_bin_info_compute_alloc(tcache_bin_info, tcache_nbins,
-	    &tcache_size, &alignment);
 
 	size_t size = tcache_size + sizeof(tcache_t)
 	    + sizeof(tcache_slow_t);
@@ -888,7 +913,8 @@ tcache_create_explicit(tsd_t *tsd) {
 	tcache_slow_t *tcache_slow =
 	    (void *)((byte_t *)mem + tcache_size + sizeof(tcache_t));
 	tcache_default_settings_init(tcache_slow);
-	tcache_init(tsd, tcache_slow, tcache, mem, tcache_bin_info);
+	tcache_init(tsd, tcache_slow, tcache, mem,
+	    tcache_get_default_ncached_max());
 
 	tcache_arena_associate(tsd_tsdn(tsd), tcache_slow, tcache,
 	    arena_ichoose(tsd, NULL));
@@ -909,7 +935,8 @@ tsd_tcache_enabled_data_init(tsd_t *tsd) {
 
 	if (opt_tcache) {
 		/* Trigger tcache init. */
-		tsd_tcache_data_init(tsd, NULL);
+		tsd_tcache_data_init(tsd, NULL,
+		    tcache_get_default_ncached_max());
 	}
 
 	return false;
@@ -920,7 +947,8 @@ tcache_enabled_set(tsd_t *tsd, bool enabled) {
 	bool was_enabled = tsd_tcache_enabled_get(tsd);
 
 	if (!was_enabled && enabled) {
-		tsd_tcache_data_init(tsd, NULL);
+		tsd_tcache_data_init(tsd, NULL,
+		    tcache_get_default_ncached_max());
 	} else if (was_enabled && !enabled) {
 		tcache_cleanup(tsd);
 	}
@@ -956,13 +984,79 @@ thread_tcache_max_set(tsd_t *tsd, size_t tcache_max) {
 	tcache_max_set(tcache_slow, tcache_max);
 
 	if (enabled) {
-		tsd_tcache_data_init_with_bin_settings(tsd, assigned_arena,
+		tsd_tcache_data_init(tsd, assigned_arena, tcache_bin_info);
-		    tcache_bin_info);
 	}
 
 	assert(tcache_nbins_get(tcache_slow) == sz_size2index(tcache_max) + 1);
 }
 
+static bool
+tcache_bin_info_settings_parse(const char *bin_settings_segment_cur,
+    size_t len_left, cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX],
+    bool bin_info_is_set[TCACHE_NBINS_MAX]) {
+	do {
+		size_t size_start, size_end;
+		size_t ncached_max;
+		bool err = multi_setting_parse_next(&bin_settings_segment_cur,
+		    &len_left, &size_start, &size_end, &ncached_max);
+		if (err) {
+			return true;
+		}
+		if (size_end > TCACHE_MAXCLASS_LIMIT) {
+			size_end = TCACHE_MAXCLASS_LIMIT;
+		}
+		if (size_start > TCACHE_MAXCLASS_LIMIT ||
+		    size_start > size_end) {
+			continue;
+		}
+		/* May get called before sz_init (during malloc_conf_init). */
+		szind_t bin_start = sz_size2index_compute(size_start);
+		szind_t bin_end = sz_size2index_compute(size_end);
+		if (ncached_max > CACHE_BIN_NCACHED_MAX) {
+			ncached_max = (size_t)CACHE_BIN_NCACHED_MAX;
+		}
+		for (szind_t i = bin_start; i <= bin_end; i++) {
+			cache_bin_info_init(&tcache_bin_info[i],
+			    (cache_bin_sz_t)ncached_max);
+			if (bin_info_is_set != NULL) {
+				bin_info_is_set[i] = true;
+			}
+		}
+	} while (len_left > 0);
+
+	return false;
+}
+
+bool
+tcache_bin_info_default_init(const char *bin_settings_segment_cur,
+    size_t len_left) {
+	return tcache_bin_info_settings_parse(bin_settings_segment_cur,
+	    len_left, opt_tcache_ncached_max, opt_tcache_ncached_max_set);
+}
+
+
+bool
+tcache_bins_ncached_max_write(tsd_t *tsd, char *settings, size_t len) {
+	assert(tcache_available(tsd));
+	assert(len != 0);
+	tcache_t *tcache = tsd_tcachep_get(tsd);
+	assert(tcache != NULL);
+	cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX];
+	tcache_bin_settings_backup(tcache, tcache_bin_info);
+
+	if(tcache_bin_info_settings_parse(settings, len, tcache_bin_info,
+	    NULL)) {
+		return true;
+	}
+
+	arena_t *assigned_arena = tcache->tcache_slow->arena;
+	tcache_cleanup(tsd);
+	tsd_tcache_data_init(tsd, assigned_arena,
+	    tcache_bin_info);
+
+	return false;
+}
+
 static void
 tcache_flush_cache(tsd_t *tsd, tcache_t *tcache) {
 	tcache_slow_t *tcache_slow = tcache->tcache_slow;
@@ -999,7 +1093,7 @@ tcache_destroy(tsd_t *tsd, tcache_t *tcache, bool tsd_tcache) {
 
 	if (tsd_tcache) {
 		cache_bin_t *cache_bin = &tcache->bins[0];
-		cache_bin_assert_empty(cache_bin, &cache_bin->bin_info);
+		cache_bin_assert_empty(cache_bin);
 	}
 	if (tsd_tcache && cache_bin_stack_use_thp()) {
 		b0_dalloc_tcache_stack(tsd_tsdn(tsd), tcache_slow->dyn_alloc);
@@ -1180,8 +1274,15 @@ bool
 tcache_boot(tsdn_t *tsdn, base_t *base) {
 	global_do_not_change_tcache_maxclass = sz_s2u(opt_tcache_max);
 	assert(global_do_not_change_tcache_maxclass <= TCACHE_MAXCLASS_LIMIT);
-	global_do_not_change_nbins =
+	global_do_not_change_tcache_nbins =
 	    sz_size2index(global_do_not_change_tcache_maxclass) + 1;
+	/*
+	 * Pre-compute default bin info and store the results in
+	 * opt_tcache_ncached_max. After the changes here,
+	 * opt_tcache_ncached_max should not be modified and should always be
+	 * accessed using tcache_get_default_ncached_max.
+	 */
+	tcache_bin_info_compute(opt_tcache_ncached_max);
 
 	if (malloc_mutex_init(&tcaches_mtx, "tcaches", WITNESS_RANK_TCACHES,
 	    malloc_mutex_rank_exclusive)) {

src/util.c

@@ -0,0 +1,49 @@
+#include "jemalloc/internal/jemalloc_preamble.h"
+#include "jemalloc/internal/jemalloc_internal_includes.h"
+
+#include "jemalloc/internal/util.h"
+
+/* Reads the next size pair in a multi-sized option. */
+bool
+multi_setting_parse_next(const char **setting_segment_cur, size_t *len_left,
+    size_t *key_start, size_t *key_end, size_t *value) {
+	const char *cur = *setting_segment_cur;
+	char *end;
+	uintmax_t um;
+
+	set_errno(0);
+
+	/* First number, then '-' */
+	um = malloc_strtoumax(cur, &end, 0);
+	if (get_errno() != 0 || *end != '-') {
+		return true;
+	}
+	*key_start = (size_t)um;
+	cur = end + 1;
+
+	/* Second number, then ':' */
+	um = malloc_strtoumax(cur, &end, 0);
+	if (get_errno() != 0 || *end != ':') {
+		return true;
+	}
+	*key_end = (size_t)um;
+	cur = end + 1;
+
+	/* Last number */
+	um = malloc_strtoumax(cur, &end, 0);
+	if (get_errno() != 0) {
+		return true;
+	}
+	*value = (size_t)um;
+
+	/* Consume the separator if there is one. */
+	if (*end == '|') {
+		end++;
+	}
+
+	*len_left -= end - *setting_segment_cur;
+	*setting_segment_cur = end;
+
+	return false;
+}
+

test/unit/cache_bin.c

@@ -1,19 +1,18 @@
 #include "test/jemalloc_test.h"
 
 static void
-do_fill_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
+do_fill_test(cache_bin_t *bin, void **ptrs, cache_bin_sz_t ncached_max,
-    cache_bin_sz_t ncached_max, cache_bin_sz_t nfill_attempt,
+    cache_bin_sz_t nfill_attempt, cache_bin_sz_t nfill_succeed) {
-    cache_bin_sz_t nfill_succeed) {
 	bool success;
 	void *ptr;
-	assert_true(cache_bin_ncached_get_local(bin, info) == 0, "");
+	assert_true(cache_bin_ncached_get_local(bin) == 0, "");
 	CACHE_BIN_PTR_ARRAY_DECLARE(arr, nfill_attempt);
-	cache_bin_init_ptr_array_for_fill(bin, info, &arr, nfill_attempt);
+	cache_bin_init_ptr_array_for_fill(bin, &arr, nfill_attempt);
 	for (cache_bin_sz_t i = 0; i < nfill_succeed; i++) {
 		arr.ptr[i] = &ptrs[i];
 	}
-	cache_bin_finish_fill(bin, info, &arr, nfill_succeed);
+	cache_bin_finish_fill(bin, &arr, nfill_succeed);
-	expect_true(cache_bin_ncached_get_local(bin, info) == nfill_succeed,
+	expect_true(cache_bin_ncached_get_local(bin) == nfill_succeed,
 	    "");
 	cache_bin_low_water_set(bin);
 
@@ -22,18 +21,18 @@ do_fill_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
 		expect_true(success, "");
 		expect_ptr_eq(ptr, (void *)&ptrs[i],
 		    "Should pop in order filled");
-		expect_true(cache_bin_low_water_get(bin, info)
+		expect_true(cache_bin_low_water_get(bin)
 		    == nfill_succeed - i - 1, "");
 	}
-	expect_true(cache_bin_ncached_get_local(bin, info) == 0, "");
+	expect_true(cache_bin_ncached_get_local(bin) == 0, "");
-	expect_true(cache_bin_low_water_get(bin, info) == 0, "");
+	expect_true(cache_bin_low_water_get(bin) == 0, "");
 }
 
 static void
-do_flush_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
+do_flush_test(cache_bin_t *bin, void **ptrs, cache_bin_sz_t nfill,
-    cache_bin_sz_t nfill, cache_bin_sz_t nflush) {
+    cache_bin_sz_t nflush) {
 	bool success;
-	assert_true(cache_bin_ncached_get_local(bin, info) == 0, "");
+	assert_true(cache_bin_ncached_get_local(bin) == 0, "");
 
 	for (cache_bin_sz_t i = 0; i < nfill; i++) {
 		success = cache_bin_dalloc_easy(bin, &ptrs[i]);
@@ -41,30 +40,30 @@ do_flush_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
 	}
 
 	CACHE_BIN_PTR_ARRAY_DECLARE(arr, nflush);
-	cache_bin_init_ptr_array_for_flush(bin, info, &arr, nflush);
+	cache_bin_init_ptr_array_for_flush(bin, &arr, nflush);
 	for (cache_bin_sz_t i = 0; i < nflush; i++) {
 		expect_ptr_eq(arr.ptr[i], &ptrs[nflush - i - 1], "");
 	}
-	cache_bin_finish_flush(bin, info, &arr, nflush);
+	cache_bin_finish_flush(bin, &arr, nflush);
 
-	expect_true(cache_bin_ncached_get_local(bin, info) == nfill - nflush,
+	expect_true(cache_bin_ncached_get_local(bin) == nfill - nflush,
 	    "");
-	while (cache_bin_ncached_get_local(bin, info) > 0) {
+	while (cache_bin_ncached_get_local(bin) > 0) {
 		cache_bin_alloc(bin, &success);
 	}
 }
 
 static void
-do_batch_alloc_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
+do_batch_alloc_test(cache_bin_t *bin, void **ptrs, cache_bin_sz_t nfill,
-    cache_bin_sz_t nfill, size_t batch) {
+    size_t batch) {
-	assert_true(cache_bin_ncached_get_local(bin, info) == 0, "");
+	assert_true(cache_bin_ncached_get_local(bin) == 0, "");
 	CACHE_BIN_PTR_ARRAY_DECLARE(arr, nfill);
-	cache_bin_init_ptr_array_for_fill(bin, info, &arr, nfill);
+	cache_bin_init_ptr_array_for_fill(bin, &arr, nfill);
 	for (cache_bin_sz_t i = 0; i < nfill; i++) {
 		arr.ptr[i] = &ptrs[i];
 	}
-	cache_bin_finish_fill(bin, info, &arr, nfill);
+	cache_bin_finish_fill(bin, &arr, nfill);
-	assert_true(cache_bin_ncached_get_local(bin, info) == nfill, "");
+	assert_true(cache_bin_ncached_get_local(bin) == nfill, "");
 	cache_bin_low_water_set(bin);
 
 	void **out = malloc((batch + 1) * sizeof(void *));
@@ -73,9 +72,9 @@ do_batch_alloc_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
 	for (cache_bin_sz_t i = 0; i < (cache_bin_sz_t)n; i++) {
 		expect_ptr_eq(out[i], &ptrs[i], "");
 	}
-	expect_true(cache_bin_low_water_get(bin, info) == nfill -
+	expect_true(cache_bin_low_water_get(bin) == nfill -
 	    (cache_bin_sz_t)n, "");
-	while (cache_bin_ncached_get_local(bin, info) > 0) {
+	while (cache_bin_ncached_get_local(bin) > 0) {
 		bool success;
 		cache_bin_alloc(bin, &success);
 	}
@@ -106,13 +105,11 @@ TEST_BEGIN(test_cache_bin) {
 	cache_bin_info_init(&info, ncached_max);
 	cache_bin_t bin;
 	test_bin_init(&bin, &info);
-	cache_bin_info_t *bin_info = &bin.bin_info;
 
 	/* Initialize to empty; should then have 0 elements. */
-	expect_d_eq(ncached_max, cache_bin_info_ncached_max_get(&bin,
+	expect_d_eq(ncached_max, cache_bin_ncached_max_get(&bin), "");
-	    &bin.bin_info), "");
+	expect_true(cache_bin_ncached_get_local(&bin) == 0, "");
-	expect_true(cache_bin_ncached_get_local(&bin, bin_info) == 0, "");
+	expect_true(cache_bin_low_water_get(&bin) == 0, "");
-	expect_true(cache_bin_low_water_get(&bin, bin_info) == 0, "");
 
 	ptr = cache_bin_alloc_easy(&bin, &success);
 	expect_false(success, "Shouldn't successfully allocate when empty");
@@ -129,14 +126,14 @@ TEST_BEGIN(test_cache_bin) {
 	void **ptrs = mallocx(sizeof(void *) * (ncached_max + 1), 0);
 	assert_ptr_not_null(ptrs, "Unexpected mallocx failure");
 	for  (cache_bin_sz_t i = 0; i < ncached_max; i++) {
-		expect_true(cache_bin_ncached_get_local(&bin, bin_info) == i, "");
+		expect_true(cache_bin_ncached_get_local(&bin) == i, "");
 		success = cache_bin_dalloc_easy(&bin, &ptrs[i]);
 		expect_true(success,
 		    "Should be able to dalloc into a non-full cache bin.");
-		expect_true(cache_bin_low_water_get(&bin, bin_info) == 0,
+		expect_true(cache_bin_low_water_get(&bin) == 0,
 		    "Pushes and pops shouldn't change low water of zero.");
 	}
-	expect_true(cache_bin_ncached_get_local(&bin, bin_info) == ncached_max,
+	expect_true(cache_bin_ncached_get_local(&bin) == ncached_max,
 	    "");
 	success = cache_bin_dalloc_easy(&bin, &ptrs[ncached_max]);
 	expect_false(success, "Shouldn't be able to dalloc into a full bin.");
@@ -144,9 +141,9 @@ TEST_BEGIN(test_cache_bin) {
 	cache_bin_low_water_set(&bin);
 
 	for (cache_bin_sz_t i = 0; i < ncached_max; i++) {
-		expect_true(cache_bin_low_water_get(&bin, bin_info)
+		expect_true(cache_bin_low_water_get(&bin)
 		    == ncached_max - i, "");
-		expect_true(cache_bin_ncached_get_local(&bin, bin_info)
+		expect_true(cache_bin_ncached_get_local(&bin)
 		    == ncached_max - i, "");
 		/*
 		 * This should fail -- the easy variant can't change the low
@@ -155,9 +152,9 @@ TEST_BEGIN(test_cache_bin) {
 		ptr = cache_bin_alloc_easy(&bin, &success);
 		expect_ptr_null(ptr, "");
 		expect_false(success, "");
-		expect_true(cache_bin_low_water_get(&bin, bin_info)
+		expect_true(cache_bin_low_water_get(&bin)
 		    == ncached_max - i, "");
-		expect_true(cache_bin_ncached_get_local(&bin, bin_info)
+		expect_true(cache_bin_ncached_get_local(&bin)
 		    == ncached_max - i, "");
 
 		/* This should succeed, though. */
@@ -165,13 +162,13 @@ TEST_BEGIN(test_cache_bin) {
 		expect_true(success, "");
 		expect_ptr_eq(ptr, &ptrs[ncached_max - i - 1],
 		    "Alloc should pop in stack order");
-		expect_true(cache_bin_low_water_get(&bin, bin_info)
+		expect_true(cache_bin_low_water_get(&bin)
 		    == ncached_max - i - 1, "");
-		expect_true(cache_bin_ncached_get_local(&bin, bin_info)
+		expect_true(cache_bin_ncached_get_local(&bin)
 		    == ncached_max - i - 1, "");
 	}
 	/* Now we're empty -- all alloc attempts should fail. */
-	expect_true(cache_bin_ncached_get_local(&bin, bin_info) == 0, "");
+	expect_true(cache_bin_ncached_get_local(&bin) == 0, "");
 	ptr = cache_bin_alloc_easy(&bin, &success);
 	expect_ptr_null(ptr, "");
 	expect_false(success, "");
@@ -187,7 +184,7 @@ TEST_BEGIN(test_cache_bin) {
 	for (cache_bin_sz_t i = ncached_max / 2; i < ncached_max; i++) {
 		cache_bin_dalloc_easy(&bin, &ptrs[i]);
 	}
-	expect_true(cache_bin_ncached_get_local(&bin, bin_info) == ncached_max,
+	expect_true(cache_bin_ncached_get_local(&bin) == ncached_max,
 	    "");
 	for (cache_bin_sz_t i = ncached_max - 1; i >= ncached_max / 2; i--) {
 		/*
@@ -204,77 +201,72 @@ TEST_BEGIN(test_cache_bin) {
 	expect_ptr_null(ptr, "");
 
 	/* We're going to test filling -- we must be empty to start. */
-	while (cache_bin_ncached_get_local(&bin, bin_info)) {
+	while (cache_bin_ncached_get_local(&bin)) {
 		cache_bin_alloc(&bin, &success);
 		expect_true(success, "");
 	}
 
 	/* Test fill. */
 	/* Try to fill all, succeed fully. */
-	do_fill_test(&bin, bin_info, ptrs, ncached_max, ncached_max,
+	do_fill_test(&bin, ptrs, ncached_max, ncached_max,
 	    ncached_max);
 	/* Try to fill all, succeed partially. */
-	do_fill_test(&bin, bin_info, ptrs, ncached_max, ncached_max,
+	do_fill_test(&bin, ptrs, ncached_max, ncached_max,
 	    ncached_max / 2);
 	/* Try to fill all, fail completely. */
-	do_fill_test(&bin, bin_info, ptrs, ncached_max, ncached_max, 0);
+	do_fill_test(&bin, ptrs, ncached_max, ncached_max, 0);
 
 	/* Try to fill some, succeed fully. */
-	do_fill_test(&bin, bin_info, ptrs, ncached_max, ncached_max / 2,
+	do_fill_test(&bin, ptrs, ncached_max, ncached_max / 2,
 	    ncached_max / 2);
 	/* Try to fill some, succeed partially. */
-	do_fill_test(&bin, bin_info, ptrs, ncached_max, ncached_max / 2,
+	do_fill_test(&bin, ptrs, ncached_max, ncached_max / 2,
 	    ncached_max / 4);
 	/* Try to fill some, fail completely. */
-	do_fill_test(&bin, bin_info, ptrs, ncached_max, ncached_max / 2, 0);
+	do_fill_test(&bin, ptrs, ncached_max, ncached_max / 2, 0);
 
-	do_flush_test(&bin, bin_info, ptrs, ncached_max, ncached_max);
+	do_flush_test(&bin, ptrs, ncached_max, ncached_max);
-	do_flush_test(&bin, bin_info, ptrs, ncached_max, ncached_max / 2);
+	do_flush_test(&bin, ptrs, ncached_max, ncached_max / 2);
-	do_flush_test(&bin, bin_info, ptrs, ncached_max, 0);
+	do_flush_test(&bin, ptrs, ncached_max, 0);
-	do_flush_test(&bin, bin_info, ptrs, ncached_max / 2, ncached_max / 2);
+	do_flush_test(&bin, ptrs, ncached_max / 2, ncached_max / 2);
-	do_flush_test(&bin, bin_info, ptrs, ncached_max / 2, ncached_max / 4);
+	do_flush_test(&bin, ptrs, ncached_max / 2, ncached_max / 4);
-	do_flush_test(&bin, bin_info, ptrs, ncached_max / 2, 0);
+	do_flush_test(&bin, ptrs, ncached_max / 2, 0);
 
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max, ncached_max);
+	do_batch_alloc_test(&bin, ptrs, ncached_max, ncached_max);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max,
+	do_batch_alloc_test(&bin, ptrs, ncached_max, ncached_max * 2);
-	    ncached_max * 2);
+	do_batch_alloc_test(&bin, ptrs, ncached_max, ncached_max / 2);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max,
+	do_batch_alloc_test(&bin, ptrs, ncached_max, 2);
-	    ncached_max / 2);
+	do_batch_alloc_test(&bin, ptrs, ncached_max, 1);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max, 2);
+	do_batch_alloc_test(&bin, ptrs, ncached_max, 0);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max, 1);
+	do_batch_alloc_test(&bin, ptrs, ncached_max / 2, ncached_max / 2);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max, 0);
+	do_batch_alloc_test(&bin, ptrs, ncached_max / 2, ncached_max);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max / 2,
+	do_batch_alloc_test(&bin, ptrs, ncached_max / 2, ncached_max / 4);
-	    ncached_max / 2);
+	do_batch_alloc_test(&bin, ptrs, ncached_max / 2, 2);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max / 2,
+	do_batch_alloc_test(&bin, ptrs, ncached_max / 2, 1);
-	    ncached_max);
+	do_batch_alloc_test(&bin, ptrs, ncached_max / 2, 0);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max / 2,
+	do_batch_alloc_test(&bin, ptrs, 2, ncached_max);
-	    ncached_max / 4);
+	do_batch_alloc_test(&bin, ptrs, 2, 2);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max / 2, 2);
+	do_batch_alloc_test(&bin, ptrs, 2, 1);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max / 2, 1);
+	do_batch_alloc_test(&bin, ptrs, 2, 0);
-	do_batch_alloc_test(&bin, bin_info, ptrs, ncached_max / 2, 0);
+	do_batch_alloc_test(&bin, ptrs, 1, 2);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 2, ncached_max);
+	do_batch_alloc_test(&bin, ptrs, 1, 1);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 2, 2);
+	do_batch_alloc_test(&bin, ptrs, 1, 0);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 2, 1);
+	do_batch_alloc_test(&bin, ptrs, 0, 2);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 2, 0);
+	do_batch_alloc_test(&bin, ptrs, 0, 1);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 1, 2);
+	do_batch_alloc_test(&bin, ptrs, 0, 0);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 1, 1);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 1, 0);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 0, 2);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 0, 1);
-	do_batch_alloc_test(&bin, bin_info, ptrs, 0, 0);
 
 	free(ptrs);
 }
 TEST_END
 
 static void
-do_flush_stashed_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
+do_flush_stashed_test(cache_bin_t *bin, void **ptrs, cache_bin_sz_t nfill,
-    cache_bin_sz_t nfill, cache_bin_sz_t nstash) {
+    cache_bin_sz_t nstash) {
-	expect_true(cache_bin_ncached_get_local(bin, info) == 0,
+	expect_true(cache_bin_ncached_get_local(bin) == 0,
 	    "Bin not empty");
-	expect_true(cache_bin_nstashed_get_local(bin, info) == 0,
+	expect_true(cache_bin_nstashed_get_local(bin) == 0,
 	    "Bin not empty");
-	expect_true(nfill + nstash <= info->ncached_max, "Exceeded max");
+	expect_true(nfill + nstash <= bin->bin_info.ncached_max, "Exceeded max");
 
 	bool ret;
 	/* Fill */
@@ -282,7 +274,7 @@ do_flush_stashed_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
 		ret = cache_bin_dalloc_easy(bin, &ptrs[i]);
 		expect_true(ret, "Unexpected fill failure");
 	}
-	expect_true(cache_bin_ncached_get_local(bin, info) == nfill,
+	expect_true(cache_bin_ncached_get_local(bin) == nfill,
 	    "Wrong cached count");
 
 	/* Stash */
@@ -290,10 +282,10 @@ do_flush_stashed_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
 		ret = cache_bin_stash(bin, &ptrs[i + nfill]);
 		expect_true(ret, "Unexpected stash failure");
 	}
-	expect_true(cache_bin_nstashed_get_local(bin, info) == nstash,
+	expect_true(cache_bin_nstashed_get_local(bin) == nstash,
 	    "Wrong stashed count");
 
-	if (nfill + nstash == info->ncached_max) {
+	if (nfill + nstash == bin->bin_info.ncached_max) {
 		ret = cache_bin_dalloc_easy(bin, &ptrs[0]);
 		expect_false(ret, "Should not dalloc into a full bin");
 		ret = cache_bin_stash(bin, &ptrs[0]);
@@ -308,19 +300,19 @@ do_flush_stashed_test(cache_bin_t *bin, cache_bin_info_t *info, void **ptrs,
 		expect_true((uintptr_t)ptr < (uintptr_t)&ptrs[nfill],
 		    "Should not alloc stashed ptrs");
 	}
-	expect_true(cache_bin_ncached_get_local(bin, info) == 0,
+	expect_true(cache_bin_ncached_get_local(bin) == 0,
 	    "Wrong cached count");
-	expect_true(cache_bin_nstashed_get_local(bin, info) == nstash,
+	expect_true(cache_bin_nstashed_get_local(bin) == nstash,
 	    "Wrong stashed count");
 
 	cache_bin_alloc(bin, &ret);
 	expect_false(ret, "Should not alloc stashed");
 
 	/* Clear stashed ones */
-	cache_bin_finish_flush_stashed(bin, info);
+	cache_bin_finish_flush_stashed(bin);
-	expect_true(cache_bin_ncached_get_local(bin, info) == 0,
+	expect_true(cache_bin_ncached_get_local(bin) == 0,
 	    "Wrong cached count");
-	expect_true(cache_bin_nstashed_get_local(bin, info) == 0,
+	expect_true(cache_bin_nstashed_get_local(bin) == 0,
 	    "Wrong stashed count");
 
 	cache_bin_alloc(bin, &ret);
@@ -334,7 +326,6 @@ TEST_BEGIN(test_cache_bin_stash) {
 	cache_bin_info_t info;
 	cache_bin_info_init(&info, ncached_max);
 	test_bin_init(&bin, &info);
-	cache_bin_info_t *bin_info = &bin.bin_info;
 
 	/*
 	 * The content of this array is not accessed; instead the interior
@@ -344,9 +335,9 @@ TEST_BEGIN(test_cache_bin_stash) {
 	assert_ptr_not_null(ptrs, "Unexpected mallocx failure");
 	bool ret;
 	for (cache_bin_sz_t i = 0; i < ncached_max; i++) {
-		expect_true(cache_bin_ncached_get_local(&bin, bin_info) ==
+		expect_true(cache_bin_ncached_get_local(&bin) ==
 		    (i / 2 + i % 2), "Wrong ncached value");
-		expect_true(cache_bin_nstashed_get_local(&bin, bin_info) ==
+		expect_true(cache_bin_nstashed_get_local(&bin) ==
 		    i / 2, "Wrong nstashed value");
 		if (i % 2 == 0) {
 			cache_bin_dalloc_easy(&bin, &ptrs[i]);
@@ -369,22 +360,21 @@ TEST_BEGIN(test_cache_bin_stash) {
 			expect_true(diff % 2 == 0, "Should be able to alloc");
 		} else {
 			expect_false(ret, "Should not alloc stashed");
-			expect_true(cache_bin_nstashed_get_local(&bin,
+			expect_true(cache_bin_nstashed_get_local(&bin) == ncached_max / 2,
-			    bin_info) == ncached_max / 2,
 			    "Wrong nstashed value");
 		}
 	}
 
 	test_bin_init(&bin, &info);
-	do_flush_stashed_test(&bin, bin_info, ptrs, ncached_max, 0);
+	do_flush_stashed_test(&bin, ptrs, ncached_max, 0);
-	do_flush_stashed_test(&bin, bin_info, ptrs, 0, ncached_max);
+	do_flush_stashed_test(&bin, ptrs, 0, ncached_max);
-	do_flush_stashed_test(&bin, bin_info, ptrs, ncached_max / 2,
+	do_flush_stashed_test(&bin, ptrs, ncached_max / 2,
 	    ncached_max / 2);
-	do_flush_stashed_test(&bin, bin_info, ptrs, ncached_max / 4,
+	do_flush_stashed_test(&bin, ptrs, ncached_max / 4,
 	    ncached_max / 2);
-	do_flush_stashed_test(&bin, bin_info, ptrs, ncached_max / 2,
+	do_flush_stashed_test(&bin, ptrs, ncached_max / 2,
 	    ncached_max / 4);
-	do_flush_stashed_test(&bin, bin_info, ptrs, ncached_max / 4,
+	do_flush_stashed_test(&bin, ptrs, ncached_max / 4,
 	    ncached_max / 4);
 }
 TEST_END

test/unit/ncached_max.c

@@ -0,0 +1,268 @@
+#include "test/jemalloc_test.h"
+#include "test/san.h"
+
+const char *malloc_conf =
+"tcache_ncached_max:256-1024:1001|2048-2048:0|8192-8192:1,tcache_max:4096";
+extern void tcache_bin_info_compute(
+    cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX]);
+extern bool tcache_get_default_ncached_max_set(szind_t ind);
+extern const cache_bin_info_t *tcache_get_default_ncached_max(void);
+
+static void
+check_bins_info(cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX]) {
+	size_t mib_get[4], mib_get_len;
+	mib_get_len = sizeof(mib_get) / sizeof(size_t);
+	const char *get_name = "thread.tcache.ncached_max.read_sizeclass";
+	size_t ncached_max;
+	size_t sz = sizeof(size_t);
+	expect_d_eq(mallctlnametomib(get_name, mib_get, &mib_get_len), 0,
+	    "Unexpected mallctlnametomib() failure");
+
+	for (szind_t i = 0; i < TCACHE_NBINS_MAX; i++) {
+		size_t bin_size = sz_index2size(i);
+		expect_d_eq(mallctlbymib(mib_get, mib_get_len,
+		    (void *)&ncached_max, &sz,
+		    (void *)&bin_size, sizeof(size_t)), 0,
+		    "Unexpected mallctlbymib() failure");
+		expect_zu_eq(ncached_max, tcache_bin_info[i].ncached_max,
+		    "Unexpected ncached_max for bin %d", i);
+		/* Check ncached_max returned under a non-bin size. */
+		bin_size--;
+		size_t temp_ncached_max = 0;
+		expect_d_eq(mallctlbymib(mib_get, mib_get_len,
+		    (void *)&temp_ncached_max, &sz,
+		    (void *)&bin_size, sizeof(size_t)), 0,
+		    "Unexpected mallctlbymib() failure");
+		expect_zu_eq(temp_ncached_max, ncached_max,
+		    "Unexpected ncached_max for inaccurate bin size.");
+	}
+}
+
+static void *
+ncached_max_check(void* args) {
+	cache_bin_info_t tcache_bin_info[TCACHE_NBINS_MAX];
+	cache_bin_info_t tcache_bin_info_backup[TCACHE_NBINS_MAX];
+	tsd_t *tsd = tsd_fetch();
+	tcache_t *tcache = tsd_tcachep_get(tsd);
+	assert(tcache != NULL);
+	tcache_slow_t *tcache_slow = tcache->tcache_slow;
+
+
+	tcache_bin_info_compute(tcache_bin_info);
+	memcpy(tcache_bin_info_backup, tcache_bin_info,
+	    sizeof(tcache_bin_info));
+	/* Check ncached_max set by malloc_conf. */
+	for (szind_t i = 0; i < TCACHE_NBINS_MAX; i++) {
+		bool first_range = (i >= sz_size2index(256) &&
+		    i <= sz_size2index(1024));
+		bool second_range = (i == sz_size2index(2048));
+		bool third_range = (i == sz_size2index(8192));
+		cache_bin_sz_t target_ncached_max = 0;
+		if (first_range || second_range || third_range) {
+			target_ncached_max = first_range ? 1001:
+			    (second_range ? 0: 1);
+			expect_true(tcache_get_default_ncached_max_set(i),
+			    "Unexpected state for bin %u", i);
+			expect_zu_eq(target_ncached_max,
+			    tcache_bin_info[i].ncached_max,
+			    "Unexpected generated ncached_max for bin %u", i);
+			expect_zu_eq(target_ncached_max,
+			    tcache_get_default_ncached_max()[i].ncached_max,
+			    "Unexpected pre-set ncached_max for bin %u", i);
+		} else {
+			expect_false(tcache_get_default_ncached_max_set(i),
+			    "Unexpected state for bin %u", i);
+		}
+	}
+	unsigned nbins = tcache_nbins_get(tcache_slow);
+	for (szind_t i = nbins; i < TCACHE_NBINS_MAX; i++) {
+		cache_bin_info_init(&tcache_bin_info[i], 0);
+	}
+	/* Check the initial bin settings. */
+	check_bins_info(tcache_bin_info);
+
+	size_t mib_set[4], mib_set_len;
+	mib_set_len = sizeof(mib_set) / sizeof(size_t);
+	const char *set_name = "thread.tcache.ncached_max.write";
+	expect_d_eq(mallctlnametomib(set_name, mib_set, &mib_set_len), 0,
+	    "Unexpected mallctlnametomib() failure");
+
+	/* Test the ncached_max set with tcache on. */
+	char inputs[100] = "8-128:1|160-160:11|170-320:22|224-8388609:0";
+	char *inputp = inputs;
+	expect_d_eq(mallctlbymib(mib_set, mib_set_len, NULL, NULL,
+	    (void *)&inputp, sizeof(char *)), 0,
+	    "Unexpected mallctlbymib() failure");
+	for (szind_t i = 0; i < TCACHE_NBINS_MAX; i++) {
+		if (i >= sz_size2index(8) &&i <= sz_size2index(128)) {
+			cache_bin_info_init(&tcache_bin_info[i], 1);
+		}
+		if (i == sz_size2index(160)) {
+			cache_bin_info_init(&tcache_bin_info[i], 11);
+		}
+		if (i >= sz_size2index(170) && i <= sz_size2index(320)) {
+			cache_bin_info_init(&tcache_bin_info[i], 22);
+		}
+		if (i >= sz_size2index(224)) {
+			cache_bin_info_init(&tcache_bin_info[i], 0);
+		}
+		if (i >= nbins) {
+			cache_bin_info_init(&tcache_bin_info[i], 0);
+		}
+	}
+	check_bins_info(tcache_bin_info);
+
+	/*
+	 * Close the tcache and set ncached_max of some bins.  It will be
+	 * set properly but thread.tcache.ncached_max.read still returns 0
+	 * since the bin is not available yet.  After enabling the tcache,
+	 * the new setting will not be carried on.  Instead, the default
+	 * settings will be applied.
+	 */
+	bool e0 = false, e1;
+	size_t bool_sz = sizeof(bool);
+	expect_d_eq(mallctl("thread.tcache.enabled", (void *)&e1, &bool_sz,
+	    (void *)&e0, bool_sz), 0, "Unexpected mallctl() error");
+	expect_true(e1, "Unexpected previous tcache state");
+	strcpy(inputs, "0-112:8");
+	/* Setting returns ENOENT when the tcache is disabled. */
+	expect_d_eq(mallctlbymib(mib_set, mib_set_len, NULL, NULL,
+	    (void *)&inputp, sizeof(char *)), ENOENT,
+	    "Unexpected mallctlbymib() failure");
+	/* All ncached_max should return 0 once tcache is disabled. */
+	for (szind_t i = 0; i < TCACHE_NBINS_MAX; i++) {
+		cache_bin_info_init(&tcache_bin_info[i], 0);
+	}
+	check_bins_info(tcache_bin_info);
+
+	e0 = true;
+	expect_d_eq(mallctl("thread.tcache.enabled", (void *)&e1, &bool_sz,
+	    (void *)&e0, bool_sz), 0, "Unexpected mallctl() error");
+	expect_false(e1, "Unexpected previous tcache state");
+	memcpy(tcache_bin_info, tcache_bin_info_backup,
+	    sizeof(tcache_bin_info_backup));
+	for (szind_t i = tcache_nbins_get(tcache_slow); i < TCACHE_NBINS_MAX;
+	    i++) {
+		cache_bin_info_init(&tcache_bin_info[i], 0);
+	}
+	check_bins_info(tcache_bin_info);
+
+	/*
+	 * Set ncached_max of bins not enabled yet.  Then, enable them by
+	 * resetting tcache_max.  The ncached_max changes should stay.
+	 */
+	size_t tcache_max = 1024;
+	assert_d_eq(mallctl("thread.tcache.max",
+	    NULL, NULL, (void *)&tcache_max, sizeof(size_t)),.0,
+	    "Unexpected.mallctl().failure");
+	for (szind_t i = sz_size2index(1024) + 1; i < TCACHE_NBINS_MAX; i++) {
+		cache_bin_info_init(&tcache_bin_info[i], 0);
+	}
+	strcpy(inputs, "2048-6144:123");
+	expect_d_eq(mallctlbymib(mib_set, mib_set_len, NULL, NULL,
+	    (void *)&inputp, sizeof(char *)), 0,
+	    "Unexpected mallctlbymib() failure");
+	check_bins_info(tcache_bin_info);
+
+	tcache_max = 6144;
+	assert_d_eq(mallctl("thread.tcache.max",
+	    NULL, NULL, (void *)&tcache_max, sizeof(size_t)),.0,
+	    "Unexpected.mallctl().failure");
+	memcpy(tcache_bin_info, tcache_bin_info_backup,
+	    sizeof(tcache_bin_info_backup));
+	for (szind_t i = sz_size2index(2048); i < TCACHE_NBINS_MAX; i++) {
+		if (i <= sz_size2index(6144)) {
+			cache_bin_info_init(&tcache_bin_info[i], 123);
+		} else if (i > sz_size2index(6144)) {
+			cache_bin_info_init(&tcache_bin_info[i], 0);
+		}
+	}
+	check_bins_info(tcache_bin_info);
+
+	/* Test an empty input, it should do nothing. */
+	strcpy(inputs, "");
+	expect_d_eq(mallctlbymib(mib_set, mib_set_len, NULL, NULL,
+	    (void *)&inputp, sizeof(char *)), 0,
+	    "Unexpected mallctlbymib() failure");
+	check_bins_info(tcache_bin_info);
+
+	/* Test a half-done string, it should return EINVAL and do nothing. */
+	strcpy(inputs, "4-1024:7|256-1024");
+	expect_d_eq(mallctlbymib(mib_set, mib_set_len, NULL, NULL,
+	    (void *)&inputp, sizeof(char *)), EINVAL,
+	    "Unexpected mallctlbymib() failure");
+	check_bins_info(tcache_bin_info);
+
+	/*
+	 * Test an invalid string with start size larger than end size.  It
+	 * should return success but do nothing.
+	 */
+	strcpy(inputs, "1024-256:7");
+	expect_d_eq(mallctlbymib(mib_set, mib_set_len, NULL, NULL,
+	    (void *)&inputp, sizeof(char *)), 0,
+	    "Unexpected mallctlbymib() failure");
+	check_bins_info(tcache_bin_info);
+
+	/*
+	 * Test a string exceeding the length limit, it should return EINVAL
+	 * and do nothing.
+	 */
+	char *long_inputs = (char *)malloc(10000 * sizeof(char));
+	expect_true(long_inputs != NULL, "Unexpected allocation failure.");
+	for (int i = 0; i < 200; i++) {
+		memcpy(long_inputs + i * 9, "4-1024:3|", 9);
+	}
+	memcpy(long_inputs + 200 * 9, "4-1024:3", 8);
+	long_inputs[200 * 9 + 8] = '\0';
+	inputp = long_inputs;
+	expect_d_eq(mallctlbymib(mib_set, mib_set_len, NULL, NULL,
+	    (void *)&inputp, sizeof(char *)), EINVAL,
+	    "Unexpected mallctlbymib() failure");
+	check_bins_info(tcache_bin_info);
+	free(long_inputs);
+
+	/*
+	 * Test a string with invalid characters, it should return EINVAL
+	 * and do nothing.
+	 */
+	strcpy(inputs, "k8-1024:77p");
+	inputp = inputs;
+	expect_d_eq(mallctlbymib(mib_set, mib_set_len, NULL, NULL,
+	    (void *)&inputp, sizeof(char *)), EINVAL,
+	    "Unexpected mallctlbymib() failure");
+	check_bins_info(tcache_bin_info);
+
+	/* Test large ncached_max, it should return success but capped. */
+	strcpy(inputs, "1024-1024:65540");
+	expect_d_eq(mallctlbymib(mib_set, mib_set_len, NULL, NULL,
+	    (void *)&inputp, sizeof(char *)), 0,
+	    "Unexpected mallctlbymib() failure");
+	cache_bin_info_init(&tcache_bin_info[sz_size2index(1024)],
+	    CACHE_BIN_NCACHED_MAX);
+	check_bins_info(tcache_bin_info);
+
+	return NULL;
+}
+
+TEST_BEGIN(test_ncached_max) {
+	test_skip_if(!config_stats);
+	test_skip_if(!opt_tcache);
+	test_skip_if(san_uaf_detection_enabled());
+	/* TODO: change nthreads to 8 to reduce CI loads. */
+	unsigned nthreads = 108;
+	VARIABLE_ARRAY(thd_t, threads, nthreads);
+	for (unsigned i = 0; i < nthreads; i++) {
+		thd_create(&threads[i], ncached_max_check, NULL);
+	}
+	for (unsigned i = 0; i < nthreads; i++) {
+		thd_join(threads[i], NULL);
+	}
+}
+TEST_END
+
+int
+main(void) {
+	return test(
+	    test_ncached_max);
+}
+

test/unit/tcache_max.c

@@ -81,8 +81,7 @@ tcache_bytes_read_local(void) {
 		if (tcache_bin_disabled(i, cache_bin, tcache->tcache_slow)) {
 			continue;
 		}
-		cache_bin_sz_t ncached = cache_bin_ncached_get_local(cache_bin,
+		cache_bin_sz_t ncached = cache_bin_ncached_get_local(cache_bin);
-		    &cache_bin->bin_info);
 		tcache_bytes += ncached * sz_index2size(i);
 	}
 	return tcache_bytes;
@@ -260,7 +259,7 @@ tcache_check(void *arg) {
 	expect_zu_eq(old_tcache_max, opt_tcache_max,
 	    "Unexpected default value for tcache_max");
 	tcache_nbins = tcache_nbins_get(tcache_slow);
-	expect_zu_eq(tcache_nbins, (size_t)global_do_not_change_nbins,
+	expect_zu_eq(tcache_nbins, (size_t)global_do_not_change_tcache_nbins,
 	    "Unexpected default value for tcache_nbins");
 	validate_tcache_stack(tcache);
 
@@ -370,4 +369,3 @@ main(void) {
 	    test_tcache_max,
 	    test_thread_tcache_max);
 }
-