From 59eeeadc3473e6d38dd83bc41d317b494df1f8ef Mon Sep 17 00:00:00 2001
From: Daan Leijen <daan@microsoft.com>
Date: Tue, 4 Feb 2025 12:26:21 -0800
Subject: [PATCH 1/4] only allow page_reclaim_on_free for small block pages

---
 bin/readme.md               | 2 +-
 include/mimalloc/internal.h | 2 +-
 src/free.c                  | 9 +++++----
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/bin/readme.md b/bin/readme.md
index f08b2e87..b79157de 100644
--- a/bin/readme.md
+++ b/bin/readme.md
@@ -63,7 +63,7 @@ need a specific redirection DLL:
   mode on Windows arm64. Unfortunately we cannot run x64 code emulated on Windows arm64 with
   the x64 mimalloc override directly (since the C runtime always uses `arm64ec`). Instead:
   1. Build the program as normal for x64 and link as normal with the x64 
-     `mimalloc.lib` export library.
+     `mimalloc.dll.lib` export library.
   2. Now separately build `mimalloc.dll` in `arm64ec` mode and _overwrite_ your
      previous (x64) `mimalloc.dll` -- the loader can handle the mix of arm64ec
      and x64 code. Now use `mimalloc-redirect-arm64ec.dll` to match your new
diff --git a/include/mimalloc/internal.h b/include/mimalloc/internal.h
index 8e7ed5e9..e18390a8 100644
--- a/include/mimalloc/internal.h
+++ b/include/mimalloc/internal.h
@@ -433,7 +433,7 @@ static inline bool mi_heap_is_backing(const mi_heap_t* heap) {
   return (heap->tld->heap_backing == heap);
 }
 
-static inline bool mi_heap_is_initialized(mi_heap_t* heap) {
+static inline bool mi_heap_is_initialized(const mi_heap_t* heap) {
   mi_assert_internal(heap != NULL);
   return (heap != NULL && heap != &_mi_heap_empty);
 }
diff --git a/src/free.c b/src/free.c
index 865efafa..1a81c504 100644
--- a/src/free.c
+++ b/src/free.c
@@ -185,7 +185,7 @@ void mi_free(void* p) mi_attr_noexcept
   else {
     // page is full or contains (inner) aligned blocks; use generic multi-thread path
     mi_free_generic_mt(page, p);
-  }  
+  }
 }
 
 
@@ -218,7 +218,8 @@ static void mi_decl_noinline mi_free_try_collect_mt(mi_page_t* page) mi_attr_noe
   // 2. if the page is not too full, we can try to reclaim it for ourselves
   // note: this seems a bad idea but it speeds up some benchmarks (like `larson`) quite a bit.
   if (_mi_option_get_fast(mi_option_page_reclaim_on_free) != 0 &&
-      !mi_page_is_used_at_frac(page,8) 
+      page->block_size <= MI_SMALL_MAX_OBJ_SIZE &&                    // only for small sized blocks
+      !mi_page_is_used_at_frac(page,8)                                // and not too full
       // && !mi_page_is_abandoned_mapped(page)
      )
   {
@@ -228,11 +229,11 @@ static void mi_decl_noinline mi_free_try_collect_mt(mi_page_t* page) mi_attr_noe
     // note: don't use `mi_heap_get_default()` as we may just have terminated this thread and we should
     // not reinitialize the heap for this thread. (can happen due to thread-local destructors for example -- issue #944)
     mi_heap_t* const heap = mi_prim_get_default_heap();
-    if (heap != (mi_heap_t*)&_mi_heap_empty)  // we did not already terminate our thread (can this happen?
+    if (mi_heap_is_initialized(heap))  // we did not already terminate our thread
     {
       mi_heap_t* const tagheap = _mi_heap_by_tag(heap, page->heap_tag);
       if ((tagheap != NULL) &&                         // don't reclaim across heap object types
-          (tagheap->allow_page_reclaim) &&             // we are allowed to reclaim abandoned pages
+          (tagheap->allow_page_reclaim) &&             // and we are allowed to reclaim abandoned pages
           // (page->subproc == tagheap->tld->subproc) &&  // don't reclaim across sub-processes; todo: make this check faster (integrate with _mi_heap_by_tag ? )
           (_mi_arena_memid_is_suitable(page->memid, tagheap->exclusive_arena))  // don't reclaim across unsuitable arena's; todo: inline arena_is_suitable (?)
          )

From db7930f961ceb781cd4e70140676e389db4576f1 Mon Sep 17 00:00:00 2001
From: Daan Leijen <daan@microsoft.com>
Date: Tue, 4 Feb 2025 14:58:08 -0800
Subject: [PATCH 2/4] avoid atomics in mi_free_try_collect_mt

---
 include/mimalloc/internal.h |  3 +-
 src/free.c                  | 14 ++++---
 src/heap.c                  |  8 ++--
 src/page.c                  | 80 ++++++++++++++++++++++++-------------
 4 files changed, 67 insertions(+), 38 deletions(-)

diff --git a/include/mimalloc/internal.h b/include/mimalloc/internal.h
index e18390a8..c1e55ddc 100644
--- a/include/mimalloc/internal.h
+++ b/include/mimalloc/internal.h
@@ -199,7 +199,8 @@ void          _mi_heap_collect_retired(mi_heap_t* heap, bool force);
 size_t        _mi_page_queue_append(mi_heap_t* heap, mi_page_queue_t* pq, mi_page_queue_t* append);
 void          _mi_deferred_free(mi_heap_t* heap, bool force);
 
-void          _mi_page_free_collect(mi_page_t* page,bool force);
+void          _mi_page_free_collect(mi_page_t* page, bool force);
+void          _mi_page_free_collect_partly(mi_page_t* page, mi_block_t* head);
 void          _mi_page_init(mi_heap_t* heap, mi_page_t* page);
 
 size_t        _mi_bin_size(uint8_t bin); // for stats
diff --git a/src/free.c b/src/free.c
index 1a81c504..ebcf08ab 100644
--- a/src/free.c
+++ b/src/free.c
@@ -48,7 +48,7 @@ static inline void mi_free_block_local(mi_page_t* page, mi_block_t* block, bool
 }
 
 // Forward declaration for multi-threaded collect
-static void mi_decl_noinline mi_free_try_collect_mt(mi_page_t* page) mi_attr_noexcept;
+static void mi_decl_noinline mi_free_try_collect_mt(mi_page_t* page, mi_block_t* mt_free) mi_attr_noexcept;
 
 // Free a block multi-threaded
 static inline void mi_free_block_mt(mi_page_t* page, mi_block_t* block) mi_attr_noexcept
@@ -69,14 +69,14 @@ static inline void mi_free_block_mt(mi_page_t* page, mi_block_t* block) mi_attr_
   mi_thread_free_t tf_old = mi_atomic_load_relaxed(&page->xthread_free);
   do {
     mi_block_set_next(page, block, mi_tf_block(tf_old));
-    tf_new = mi_tf_create(block, true /* always owned: try to claim it if abandoned */);
+    tf_new = mi_tf_create(block, true /* always use owned: try to claim it if the page is abandoned */);
   } while (!mi_atomic_cas_weak_acq_rel(&page->xthread_free, &tf_old, tf_new)); // todo: release is enough?
 
   // and atomically try to collect the page if it was abandoned
   const bool is_owned_now = !mi_tf_is_owned(tf_old);
   if (is_owned_now) {
     mi_assert_internal(mi_page_is_abandoned(page));
-    mi_free_try_collect_mt(page);
+    mi_free_try_collect_mt(page,block);
   }
 }
 
@@ -194,18 +194,20 @@ void mi_free(void* p) mi_attr_noexcept
 // ------------------------------------------------------
 
 
-static void mi_decl_noinline mi_free_try_collect_mt(mi_page_t* page) mi_attr_noexcept {
+static void mi_decl_noinline mi_free_try_collect_mt(mi_page_t* page, mi_block_t* mt_free) mi_attr_noexcept {
   mi_assert_internal(mi_page_is_owned(page));
   mi_assert_internal(mi_page_is_abandoned(page));
 
   // we own the page now..
   // safe to collect the thread atomic free list
-  _mi_page_free_collect(page, false);  // update `used` count
+  // use the `_partly` version to avoid atomic operations since we already have the `mt_free` pointing into the thread free list
+  _mi_page_free_collect_partly(page, mt_free);
+
   #if MI_DEBUG > 1
   if (mi_page_is_singleton(page)) { mi_assert_internal(mi_page_all_free(page)); }
   #endif
 
-  // 1. free if the page is free now
+  // 1. free if the page is free now  (this is updated by `_mi_page_free_collect_partly`)
   if (mi_page_all_free(page))
   {
     // first remove it from the abandoned pages in the arena (if mapped, this waits for any readers to finish)
diff --git a/src/heap.c b/src/heap.c
index 1ae7e99f..10c65ff2 100644
--- a/src/heap.c
+++ b/src/heap.c
@@ -115,14 +115,14 @@ static void mi_heap_collect_ex(mi_heap_t* heap, mi_collect_t collect)
 
   // collect retired pages
   _mi_heap_collect_retired(heap, force);
-  
+
   // if (_mi_is_main_thread()) { mi_debug_show_arenas(true, false, false); }
-  
+
   // collect all pages owned by this thread
   mi_heap_visit_pages(heap, &mi_heap_page_collect, &collect, NULL);
 
-  // collect arenas (this is program wide so don't force purges on abandonment of threads)  
-  //mi_atomic_storei64_release(&heap->tld->subproc->purge_expire, 1); 
+  // collect arenas (this is program wide so don't force purges on abandonment of threads)
+  //mi_atomic_storei64_release(&heap->tld->subproc->purge_expire, 1);
   _mi_arenas_collect(collect == MI_FORCE /* force purge? */, collect >= MI_FORCE /* visit all? */, heap->tld);
 }
 
diff --git a/src/page.c b/src/page.c
index af1d5072..ccb4445b 100644
--- a/src/page.c
+++ b/src/page.c
@@ -137,9 +137,39 @@ bool _mi_page_is_valid(mi_page_t* page) {
   Page collect the `local_free` and `thread_free` lists
 ----------------------------------------------------------- */
 
-// Collect the local `thread_free` list using an atomic exchange.
-static void _mi_page_thread_free_collect(mi_page_t* page)
+static void mi_page_thread_collect_to_local(mi_page_t* page, mi_block_t* head)
 {
+  if (head == NULL) return;
+
+  // find the last block in the list -- also to get a proper use count (without data races)
+  size_t max_count = page->capacity; // cannot collect more than capacity
+  size_t count = 1;
+  mi_block_t* last = head;
+  mi_block_t* next;
+  while ((next = mi_block_next(page, last)) != NULL && count <= max_count) {
+    count++;
+    last = next;
+  }
+
+  // if `count > max_count` there was a memory corruption (possibly infinite list due to double multi-threaded free)
+  if (count > max_count) {
+    _mi_error_message(EFAULT, "corrupted thread-free list\n");
+    return; // the thread-free items cannot be freed
+  }
+
+  // and append the current local free list
+  mi_block_set_next(page, last, page->local_free);
+  page->local_free = head;
+
+  // update counts now
+  mi_assert_internal(count <= UINT16_MAX);
+  page->used = page->used - (uint16_t)count;
+}
+
+// Collect the local `thread_free` list using an atomic exchange.
+static void mi_page_thread_free_collect(mi_page_t* page)
+{
+  // atomically capture the thread free list
   mi_block_t* head;
   mi_thread_free_t tfreex;
   mi_thread_free_t tfree = mi_atomic_load_relaxed(&page->xthread_free);
@@ -150,35 +180,15 @@ static void _mi_page_thread_free_collect(mi_page_t* page)
   } while (!mi_atomic_cas_weak_acq_rel(&page->xthread_free, &tfree, tfreex));  // release is enough?
   mi_assert_internal(head != NULL);
 
-  // find the tail -- also to get a proper count (without data races)
-  size_t max_count = page->capacity; // cannot collect more than capacity
-  size_t count = 1;
-  mi_block_t* tail = head;
-  mi_block_t* next;
-  while( (next = mi_block_next(page,tail)) != NULL && count <= max_count) {
-    count++;
-    tail = next;
-  }
-
-  // if `count > max_count` there was a memory corruption (possibly infinite list due to double multi-threaded free)
-  if (count > max_count) {
-    _mi_error_message(EFAULT, "corrupted thread-free list\n");
-    return; // the thread-free items cannot be freed
-  }
-
-  // and append the current local free list
-  mi_block_set_next(page,tail, page->local_free);
-  page->local_free = head;
-
-  // update counts now
-  page->used -= (uint16_t)count;
+  // and move it to the local list
+  mi_page_thread_collect_to_local(page, head);
 }
 
 void _mi_page_free_collect(mi_page_t* page, bool force) {
   mi_assert_internal(page!=NULL);
 
   // collect the thread free list
-  _mi_page_thread_free_collect(page);
+  mi_page_thread_free_collect(page);
 
   // and the local free list
   if (page->local_free != NULL) {
@@ -205,6 +215,23 @@ void _mi_page_free_collect(mi_page_t* page, bool force) {
   mi_assert_internal(!force || page->local_free == NULL);
 }
 
+// collect elements in the thread-free list starting at `head`.
+void _mi_page_free_collect_partly(mi_page_t* page, mi_block_t* head) {
+  if (head == NULL) return;
+  mi_block_t* next = mi_block_next(page,head);  // we cannot collect the head element itself as `page->thread_free` may point at it (and we want to avoid atomic ops)
+  if (next != NULL) {
+    mi_page_thread_collect_to_local(page, next);
+    if (page->local_free != NULL && page->free == NULL) {
+      page->free = page->local_free;
+      page->local_free = NULL;
+      page->free_is_zero = false;
+    }
+  }
+  if (page->used == 1) {
+    // all elements are free'd since we skipped the `head` element itself
+    _mi_page_free_collect(page, false);  // collect the final element
+  }
+}
 
 
 /* -----------------------------------------------------------
@@ -333,9 +360,8 @@ static void mi_page_to_full(mi_page_t* page, mi_page_queue_t* pq) {
     // abandon full pages
     _mi_page_abandon(page, pq);
   }
-  else {
+  else if (!mi_page_is_in_full(page)) {
     // put full pages in a heap local queue
-    if (mi_page_is_in_full(page)) return;
     mi_page_queue_enqueue_from(&mi_page_heap(page)->pages[MI_BIN_FULL], pq, page);
     _mi_page_free_collect(page, false);  // try to collect right away in case another thread freed just before MI_USE_DELAYED_FREE was set
   }

From b0c8d86c41066832d35db85952d65f483b1fecf6 Mon Sep 17 00:00:00 2001
From: Daan Leijen <daan@microsoft.com>
Date: Tue, 4 Feb 2025 15:03:27 -0800
Subject: [PATCH 3/4] refactor mi_free_try_collect_mt

---
 src/free.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/free.c b/src/free.c
index ebcf08ab..5e83ad95 100644
--- a/src/free.c
+++ b/src/free.c
@@ -217,12 +217,13 @@ static void mi_decl_noinline mi_free_try_collect_mt(mi_page_t* page, mi_block_t*
     return;
   }
 
+  const bool too_full = mi_page_is_used_at_frac(page, 8);  // more than 7/8th of the page is in use?
+
   // 2. if the page is not too full, we can try to reclaim it for ourselves
   // note: this seems a bad idea but it speeds up some benchmarks (like `larson`) quite a bit.
-  if (_mi_option_get_fast(mi_option_page_reclaim_on_free) != 0 &&
-      page->block_size <= MI_SMALL_MAX_OBJ_SIZE &&                    // only for small sized blocks
-      !mi_page_is_used_at_frac(page,8)                                // and not too full
-      // && !mi_page_is_abandoned_mapped(page)
+  if (!too_full &&
+      _mi_option_get_fast(mi_option_page_reclaim_on_free) != 0 &&
+      page->block_size <= MI_SMALL_MAX_OBJ_SIZE         // only for small sized blocks
      )
   {
     // the page has still some blocks in use (but not too many)
@@ -252,7 +253,7 @@ static void mi_decl_noinline mi_free_try_collect_mt(mi_page_t* page, mi_block_t*
   }
 
   // 3. if the page is unmapped, try to reabandon so it can possibly be mapped and found for allocations
-  if (!mi_page_is_used_at_frac(page,8) &&  // only reabandon if a full page starts to have enough blocks available to prevent immediate re-abandon of a full page
+  if (!too_full &&  // only reabandon if a full page starts to have enough blocks available to prevent immediate re-abandon of a full page
       !mi_page_is_abandoned_mapped(page) && page->memid.memkind == MI_MEM_ARENA &&
       _mi_arenas_page_try_reabandon_to_mapped(page))
   {

From 8fc8da5d81bcee92650752d473603ea42a6fb203 Mon Sep 17 00:00:00 2001
From: Daan Leijen <daan@microsoft.com>
Date: Tue, 4 Feb 2025 17:54:49 -0800
Subject: [PATCH 4/4] use thread local stats for abandoned statistics to reduce
 contention

---
 include/mimalloc/internal.h |  3 ++-
 include/mimalloc/types.h    | 13 ++++++++++---
 src/arena.c                 | 25 +++++++++++++------------
 src/init.c                  | 12 ++++++++++++
 src/page.c                  |  2 +-
 src/stats.c                 |  6 ++++++
 6 files changed, 44 insertions(+), 17 deletions(-)

diff --git a/include/mimalloc/internal.h b/include/mimalloc/internal.h
index c1e55ddc..92f02788 100644
--- a/include/mimalloc/internal.h
+++ b/include/mimalloc/internal.h
@@ -116,6 +116,7 @@ mi_subproc_t* _mi_subproc_main(void);
 mi_subproc_t* _mi_subproc_from_id(mi_subproc_id_t subproc_id);
 mi_threadid_t _mi_thread_id(void) mi_attr_noexcept;
 size_t        _mi_thread_seq_id(void) mi_attr_noexcept;
+mi_tld_t*     _mi_thread_tld(void) mi_attr_noexcept;
 void          _mi_heap_guarded_init(mi_heap_t* heap);
 
 // os.c
@@ -171,7 +172,7 @@ void          _mi_arenas_unsafe_destroy_all(mi_tld_t* tld);
 
 mi_page_t*    _mi_arenas_page_alloc(mi_heap_t* heap, size_t block_size, size_t page_alignment);
 void          _mi_arenas_page_free(mi_page_t* page);
-void          _mi_arenas_page_abandon(mi_page_t* page);
+void          _mi_arenas_page_abandon(mi_page_t* page, mi_tld_t* tld);
 void          _mi_arenas_page_unabandon(mi_page_t* page);
 bool          _mi_arenas_page_try_reabandon_to_mapped(mi_page_t* page);
 
diff --git a/include/mimalloc/types.h b/include/mimalloc/types.h
index 0bf5722b..6ed17f09 100644
--- a/include/mimalloc/types.h
+++ b/include/mimalloc/types.h
@@ -544,13 +544,20 @@ void __mi_stat_counter_increase_mt(mi_stat_counter_t* stat, size_t amount);
 #define mi_subproc_stat_adjust_increase(subproc,stat,amnt,b)    __mi_stat_adjust_increase_mt( &(subproc)->stats.stat, amnt, b)
 #define mi_subproc_stat_adjust_decrease(subproc,stat,amnt,b)    __mi_stat_adjust_decrease_mt( &(subproc)->stats.stat, amnt, b)
 
+#define mi_tld_stat_counter_increase(tld,stat,amount)           __mi_stat_counter_increase( &(tld)->stats.stat, amount)
+#define mi_tld_stat_increase(tld,stat,amount)                   __mi_stat_increase( &(tld)->stats.stat, amount)
+#define mi_tld_stat_decrease(tld,stat,amount)                   __mi_stat_decrease( &(tld)->stats.stat, amount)
+#define mi_tld_stat_adjust_increase(tld,stat,amnt,b)            __mi_stat_adjust_increase( &(tld)->stats.stat, amnt, b)
+#define mi_tld_stat_adjust_decrease(tld,stat,amnt,b)            __mi_stat_adjust_decrease( &(tld)->stats.stat, amnt, b)
+
+
 #define mi_os_stat_counter_increase(stat,amount)                mi_subproc_stat_counter_increase(_mi_subproc(),stat,amount)
 #define mi_os_stat_increase(stat,amount)                        mi_subproc_stat_increase(_mi_subproc(),stat,amount)
 #define mi_os_stat_decrease(stat,amount)                        mi_subproc_stat_decrease(_mi_subproc(),stat,amount)
 
-#define mi_heap_stat_counter_increase(heap,stat,amount)         __mi_stat_counter_increase( &(heap)->tld->stats.stat, amount)
-#define mi_heap_stat_increase(heap,stat,amount)                 __mi_stat_increase( &(heap)->tld->stats.stat, amount)
-#define mi_heap_stat_decrease(heap,stat,amount)                 __mi_stat_decrease( &(heap)->tld->stats.stat, amount)
+#define mi_heap_stat_counter_increase(heap,stat,amount)         mi_tld_stat_counter_increase(heap->tld, stat, amount)
+#define mi_heap_stat_increase(heap,stat,amount)                 mi_tld_stat_increase( heap->tld, stat, amount)
+#define mi_heap_stat_decrease(heap,stat,amount)                 mi_tld_stat_decrease( heap->tld, stat, amount)
 
 #define mi_debug_heap_stat_counter_increase(heap,stat,amount)   mi_debug_stat_counter_increase( (heap)->tld->stats.stat, amount)
 #define mi_debug_heap_stat_increase(heap,stat,amount)           mi_debug_stat_increase( (heap)->tld->stats.stat, amount)
diff --git a/src/arena.c b/src/arena.c
index e111a417..ca2ea164 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -563,8 +563,9 @@ static mi_page_t* mi_arenas_page_try_find_abandoned(mi_subproc_t* subproc, size_
       mi_assert_internal(mi_page_is_abandoned(page));
       mi_assert_internal(mi_arena_has_page(arena,page));
       mi_atomic_decrement_relaxed(&subproc->abandoned_count[bin]);
-      mi_subproc_stat_decrease( arena->subproc, pages_abandoned, 1);
-      mi_subproc_stat_counter_increase(arena->subproc, pages_reclaim_on_alloc, 1);
+      mi_tld_t* tld = _mi_thread_tld();
+      mi_tld_stat_decrease( tld, pages_abandoned, 1);
+      mi_tld_stat_counter_increase( tld, pages_reclaim_on_alloc, 1);
 
       _mi_page_free_collect(page, false);  // update `used` count
       mi_assert_internal(mi_bbitmap_is_clearN(arena->slices_free, slice_index, slice_count));
@@ -855,7 +856,7 @@ void _mi_arenas_page_free(mi_page_t* page) {
   Arena abandon
 ----------------------------------------------------------- */
 
-void _mi_arenas_page_abandon(mi_page_t* page) {
+void _mi_arenas_page_abandon(mi_page_t* page, mi_tld_t* tld) {
   mi_assert_internal(_mi_is_aligned(page, MI_PAGE_ALIGN));
   mi_assert_internal(_mi_ptr_page(page)==page);
   mi_assert_internal(mi_page_is_owned(page));
@@ -878,7 +879,7 @@ void _mi_arenas_page_abandon(mi_page_t* page) {
     const bool wasclear = mi_bitmap_set(arena->pages_abandoned[bin], slice_index);
     MI_UNUSED(wasclear); mi_assert_internal(wasclear);
     mi_atomic_increment_relaxed(&arena->subproc->abandoned_count[bin]);
-    mi_subproc_stat_increase(arena->subproc, pages_abandoned, 1);
+    mi_tld_stat_increase(tld, pages_abandoned, 1);
   }
   else {
     // page is full (or a singleton), or the page is OS/externally allocated
@@ -894,7 +895,7 @@ void _mi_arenas_page_abandon(mi_page_t* page) {
         subproc->os_abandoned_pages = page;
       }
     }
-    mi_subproc_stat_increase(_mi_subproc(), pages_abandoned, 1);
+    mi_tld_stat_increase(tld, pages_abandoned, 1);
   }
   _mi_page_unown(page);
 }
@@ -912,10 +913,10 @@ bool _mi_arenas_page_try_reabandon_to_mapped(mi_page_t* page) {
     return false;
   }
   else {
-    mi_subproc_t* subproc = _mi_subproc();
-    mi_subproc_stat_counter_increase( subproc, pages_reabandon_full, 1);
-    mi_subproc_stat_adjust_decrease( subproc, pages_abandoned, 1, true /* on alloc */);  // adjust as we are not abandoning fresh
-    _mi_arenas_page_abandon(page);
+    mi_tld_t* tld = _mi_thread_tld();
+    mi_tld_stat_counter_increase( tld, pages_reabandon_full, 1);
+    mi_tld_stat_adjust_decrease( tld, pages_abandoned, 1, true /* on alloc */);  // adjust as we are not abandoning fresh
+    _mi_arenas_page_abandon(page,tld);
     return true;
   }
 }
@@ -942,14 +943,14 @@ void _mi_arenas_page_unabandon(mi_page_t* page) {
     mi_bitmap_clear_once_set(arena->pages_abandoned[bin], slice_index);
     mi_page_clear_abandoned_mapped(page);
     mi_atomic_decrement_relaxed(&arena->subproc->abandoned_count[bin]);
-    mi_subproc_stat_decrease(arena->subproc, pages_abandoned, 1);
+    mi_tld_stat_decrease(_mi_thread_tld(), pages_abandoned, 1);
   }
   else {
     // page is full (or a singleton), page is OS allocated
-    mi_subproc_t* subproc = _mi_subproc();
-    mi_subproc_stat_decrease(_mi_subproc(), pages_abandoned, 1);
+    mi_tld_stat_decrease(_mi_thread_tld(), pages_abandoned, 1);
     // if not an arena page, remove from the subproc os pages list
     if (page->memid.memkind != MI_MEM_ARENA && mi_option_is_enabled(mi_option_visit_abandoned)) {
+      mi_subproc_t* subproc = _mi_subproc();
       mi_lock(&subproc->os_abandoned_pages_lock) {
         if (page->prev != NULL) { page->prev->next = page->next; }
         if (page->next != NULL) { page->next->prev = page->prev; }
diff --git a/src/init.c b/src/init.c
index 33c9794d..ced30104 100644
--- a/src/init.c
+++ b/src/init.c
@@ -357,6 +357,18 @@ mi_subproc_t* _mi_subproc(void) {
 }
 
 
+mi_tld_t* _mi_thread_tld(void) mi_attr_noexcept {
+  // should work without doing initialization (as it may be called from `_mi_tld -> mi_tld_alloc ... -> os_alloc -> _mi_subproc()`
+  mi_heap_t* heap = mi_prim_get_default_heap();
+  if (heap == NULL) {
+    return &tld_empty;
+  }
+  else {
+    return heap->tld;
+  }
+}
+
+
 /* -----------------------------------------------------------
   Sub process
 ----------------------------------------------------------- */
diff --git a/src/page.c b/src/page.c
index ccb4445b..dc3a6365 100644
--- a/src/page.c
+++ b/src/page.c
@@ -280,7 +280,7 @@ void _mi_page_abandon(mi_page_t* page, mi_page_queue_t* pq) {
     mi_page_queue_remove(pq, page);
     mi_tld_t* tld = page->heap->tld;
     mi_page_set_heap(page, NULL);
-    _mi_arenas_page_abandon(page);
+    _mi_arenas_page_abandon(page,tld);
     _mi_arenas_collect(false, false, tld); // allow purging
   }
 }
diff --git a/src/stats.c b/src/stats.c
index 057dc093..d8450a84 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -152,6 +152,12 @@ static void mi_stats_add(mi_stats_t* stats, const mi_stats_t* src) {
   mi_stat_counter_add(&stats->normal_count, &src->normal_count, 1);
   mi_stat_counter_add(&stats->huge_count, &src->huge_count, 1);
   mi_stat_counter_add(&stats->guarded_alloc_count, &src->guarded_alloc_count, 1);
+
+  mi_stat_counter_add(&stats->pages_extended, &src->pages_extended, 1);
+  mi_stat_counter_add(&stats->pages_reclaim_on_alloc, &src->pages_reclaim_on_alloc, 1);
+  mi_stat_counter_add(&stats->pages_reclaim_on_free, &src->pages_reclaim_on_free, 1);
+  mi_stat_counter_add(&stats->pages_reabandon_full, &src->pages_reabandon_full, 1);
+  mi_stat_counter_add(&stats->pages_unabandon_busy_wait, &src->pages_unabandon_busy_wait, 1);
 #if MI_STAT>1
   for (size_t i = 0; i <= MI_BIN_HUGE; i++) {
     if (src->normal_bins[i].allocated > 0 || src->normal_bins[i].freed > 0) {