diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index d853db2f..b44d7740 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -43,7 +43,7 @@ jobs:
       solution: $(BuildType)/libmimalloc.sln
       configuration: '$(MSBuildConfiguration)'
       msbuildArguments: -m
-  - script: ctest --verbose --timeout 180 -C $(MSBuildConfiguration)
+  - script: ctest --verbose --timeout 240 -C $(MSBuildConfiguration)
     workingDirectory: $(BuildType)
     displayName: CTest
   #- script: $(BuildType)\$(BuildType)\mimalloc-test-stress
@@ -126,7 +126,7 @@ jobs:
       cmakeArgs: .. $(cmakeExtraArgs)
   - script: make -j$(nproc) -C $(BuildType)
     displayName: Make
-  - script: ctest --verbose --timeout 180
+  - script: ctest --verbose --timeout 240
     workingDirectory: $(BuildType)
     displayName: CTest
     env:
@@ -157,7 +157,7 @@ jobs:
       cmakeArgs: .. $(cmakeExtraArgs)
   - script: make -j$(sysctl -n hw.ncpu) -C $(BuildType)
     displayName: Make
-  - script: ctest --verbose --timeout 180
+  - script: ctest --verbose --timeout 240
     workingDirectory: $(BuildType)
     displayName: CTest
 #  - upload: $(Build.SourcesDirectory)/$(BuildType)
@@ -192,7 +192,7 @@ jobs:
       solution: $(BuildType)/libmimalloc.sln
       configuration: '$(MSBuildConfiguration)'
       msbuildArguments: -m
-  - script: ctest --verbose --timeout 180 -C $(MSBuildConfiguration)
+  - script: ctest --verbose --timeout 240 -C $(MSBuildConfiguration)
     workingDirectory: $(BuildType)
     displayName: CTest
 
@@ -235,7 +235,7 @@ jobs:
       cmakeArgs: .. $(cmakeExtraArgs)
   - script: make -j$(nproc) -C $(BuildType)
     displayName: Make
-  - script: ctest --verbose --timeout 180
+  - script: ctest --verbose --timeout 240
     workingDirectory: $(BuildType)
     displayName: CTest
 
@@ -278,7 +278,7 @@ jobs:
       cmakeArgs: .. $(cmakeExtraArgs)
   - script: make -j$(nproc) -C $(BuildType)
     displayName: Make
-  - script: ctest --verbose --timeout 180
+  - script: ctest --verbose --timeout 240
     workingDirectory: $(BuildType)
     displayName: CTest
 
@@ -302,7 +302,7 @@ jobs:
       cmakeArgs: .. $(cmakeExtraArgs)
   - script: make -j$(sysctl -n hw.ncpu) -C $(BuildType)
     displayName: Make
-  - script: ctest --verbose --timeout 180
+  - script: ctest --verbose --timeout 240
     workingDirectory: $(BuildType)
     displayName: CTest
 
diff --git a/bin/minject-arm64.exe b/bin/minject-arm64.exe
index 63987afc..97188c4f 100644
Binary files a/bin/minject-arm64.exe and b/bin/minject-arm64.exe differ
diff --git a/bin/minject.exe b/bin/minject.exe
index dba8f80f..53c42f5d 100644
Binary files a/bin/minject.exe and b/bin/minject.exe differ
diff --git a/bin/minject32.exe b/bin/minject32.exe
index f837383b..926facfd 100644
Binary files a/bin/minject32.exe and b/bin/minject32.exe differ
diff --git a/include/mimalloc/types.h b/include/mimalloc/types.h
index 920a8e2c..f95f481b 100644
--- a/include/mimalloc/types.h
+++ b/include/mimalloc/types.h
@@ -485,18 +485,27 @@ typedef struct mi_stats_s {
 } mi_stats_t;
 
 
+// add to stat keeping track of the peak
 void _mi_stat_increase(mi_stat_count_t* stat, size_t amount);
 void _mi_stat_decrease(mi_stat_count_t* stat, size_t amount);
+// adjust stat in special cases to compensate for double counting
+void _mi_stat_adjust_increase(mi_stat_count_t* stat, size_t amount);
+void _mi_stat_adjust_decrease(mi_stat_count_t* stat, size_t amount);
+// counters can just be increased
 void _mi_stat_counter_increase(mi_stat_counter_t* stat, size_t amount);
 
 #if (MI_STAT)
 #define mi_stat_increase(stat,amount)         _mi_stat_increase( &(stat), amount)
 #define mi_stat_decrease(stat,amount)         _mi_stat_decrease( &(stat), amount)
 #define mi_stat_counter_increase(stat,amount) _mi_stat_counter_increase( &(stat), amount)
+#define mi_stat_adjust_increase(stat,amount)  _mi_stat_adjust_increase( &(stat), amount)
+#define mi_stat_adjust_decrease(stat,amount)  _mi_stat_adjust_decrease( &(stat), amount)
 #else
-#define mi_stat_increase(stat,amount)         (void)0
-#define mi_stat_decrease(stat,amount)         (void)0
-#define mi_stat_counter_increase(stat,amount) (void)0
+#define mi_stat_increase(stat,amount)         ((void)0)
+#define mi_stat_decrease(stat,amount)         ((void)0)
+#define mi_stat_counter_increase(stat,amount) ((void)0)
+#define mi_stat_adjuct_increase(stat,amount)  ((void)0)
+#define mi_stat_adjust_decrease(stat,amount)  ((void)0)
 #endif
 
 #define mi_heap_stat_counter_increase(heap,stat,amount)  mi_stat_counter_increase( (heap)->tld->stats.stat, amount)
diff --git a/src/arena.c b/src/arena.c
index 6c048073..122de4d1 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -231,12 +231,24 @@ static mi_decl_noinline void* mi_arena_try_alloc_at(
     // commit requested, but the range may not be committed as a whole: ensure it is committed now
     if (!mi_bitmap_is_setN(arena->slices_committed, slice_index, slice_count)) {
       // not fully committed: commit the full range and set the commit bits
-      // (this may race and we may double-commit which is fine)
+      // we set the bits first since we own these slices (they are no longer free)
+      size_t already_committed_count = 0;
+      mi_bitmap_setN(arena->slices_committed, slice_index, slice_count, &already_committed_count);
+      // adjust the stats so we don't double count the commits
+      if (already_committed_count > 0) {
+        _mi_stat_adjust_decrease(&_mi_stats_main.committed, mi_size_of_slices(already_committed_count));
+      }
+      // now actually commit
       bool commit_zero = false;
       if (!_mi_os_commit(p, mi_size_of_slices(slice_count), &commit_zero)) {
+        // failed to commit (todo: give warning?)
+        if (already_committed_count > 0) {
+          _mi_stat_increase(&_mi_stats_main.committed, mi_size_of_slices(already_committed_count));
+        }
         memid->initially_committed = false;
       }
       else {
+        // committed
         if (commit_zero) { memid->initially_zero = true; }
         #if MI_DEBUG > 1
         if (memid->initially_zero) {
@@ -245,13 +257,7 @@ static mi_decl_noinline void* mi_arena_try_alloc_at(
             memid->initially_zero = false;
           }
         }
-        #endif
-        size_t already_committed_count = 0;
-        mi_bitmap_setN(arena->slices_committed, slice_index, slice_count, &already_committed_count);
-        if (already_committed_count < slice_count) {
-          // todo: also decrease total
-          mi_stat_decrease(_mi_stats_main.committed, mi_size_of_slices(already_committed_count));
-        }
+        #endif        
       }
     }
     if (memid->initially_zero) {
@@ -795,7 +801,7 @@ void _mi_arena_page_free(mi_page_t* page) {
   Arena abandon
 ----------------------------------------------------------- */
 
-static void mi_arena_page_abandon_no_stat(mi_page_t* page) {
+void _mi_arena_page_abandon(mi_page_t* page) {
   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));
@@ -824,12 +830,8 @@ static void mi_arena_page_abandon_no_stat(mi_page_t* page) {
     // page is full (or a singleton), page is OS/externally allocated
     // leave as is; it will be reclaimed when an object is free'd in the page
   }
-  _mi_page_unown(page);
-}
-
-void _mi_arena_page_abandon(mi_page_t* page) {
-  mi_arena_page_abandon_no_stat(page);
   _mi_stat_increase(&_mi_stats_main.pages_abandoned, 1);
+  _mi_page_unown(page);
 }
 
 bool _mi_arena_page_try_reabandon_to_mapped(mi_page_t* page) {
@@ -846,7 +848,8 @@ bool _mi_arena_page_try_reabandon_to_mapped(mi_page_t* page) {
   }
   else {
     _mi_stat_counter_increase(&_mi_stats_main.pages_reabandon_full, 1);
-    mi_arena_page_abandon_no_stat(page);
+    _mi_stat_adjust_decrease(&_mi_stats_main.pages_abandoned, 1);  // adjust as we are not abandoning fresh
+    _mi_arena_page_abandon(page);
     return true;
   }
 }
@@ -1416,19 +1419,21 @@ int mi_reserve_huge_os_pages(size_t pages, double max_secs, size_t* pages_reserv
 
 // reset or decommit in an arena and update the commit bitmap
 // assumes we own the area (i.e. slices_free is claimed by us)
-static void mi_arena_purge(mi_arena_t* arena, size_t slice_index, size_t slice_count) {
+// returns if the memory is no longer committed (versus reset which keeps the commit)
+static bool mi_arena_purge(mi_arena_t* arena, size_t slice_index, size_t slice_count) {
   mi_assert_internal(!arena->memid.is_pinned);
   mi_assert_internal(mi_bbitmap_is_clearN(arena->slices_free, slice_index, slice_count));
 
   const size_t size = mi_size_of_slices(slice_count);
   void* const p = mi_arena_slice_start(arena, slice_index);
   const bool all_committed = mi_bitmap_is_setN(arena->slices_committed, slice_index, slice_count);
-  const bool needs_recommit = _mi_os_purge_ex(p, size, all_committed);
+  const bool needs_recommit = _mi_os_purge_ex(p, size, all_committed /* allow reset? */);
 
   // update committed bitmap
   if (needs_recommit) {
     mi_bitmap_clearN(arena->slices_committed, slice_index, slice_count);
   }
+  return needs_recommit;
 }
 
 
@@ -1445,12 +1450,13 @@ static void mi_arena_schedule_purge(mi_arena_t* arena, size_t slice_index, size_
   }
   else {
     // schedule purge
-    mi_msecs_t expire = mi_atomic_loadi64_relaxed(&arena->purge_expire);
-    if (expire == 0) {
-      mi_atomic_storei64_release(&arena->purge_expire, _mi_clock_now() + delay);
+    mi_msecs_t expire0 = 0;
+    if (mi_atomic_casi64_strong_acq_rel(&arena->purge_expire, &expire0, _mi_clock_now() + delay)) {
+      // expiration was not yet set
       mi_atomic_storei64_release(&arena->purge_expire_extend, 0);      
     }
     else if (mi_atomic_loadi64_acquire(&arena->purge_expire_extend) < 10*delay) {     // limit max extension time
+      // already an expiration was set
       mi_atomic_addi64_acq_rel(&arena->purge_expire_extend, (mi_msecs_t)(delay/10));  // add smallish extra delay
     }
     mi_bitmap_setN(arena->slices_purge, slice_index, slice_count, NULL);
@@ -1467,8 +1473,8 @@ typedef struct mi_purge_visit_info_s {
 static bool mi_arena_try_purge_range(mi_arena_t* arena, size_t slice_index, size_t slice_count) {
   if (mi_bbitmap_try_clearN(arena->slices_free, slice_index, slice_count)) {
     // purge
-    mi_arena_purge(arena, slice_index, slice_count);
-    mi_assert_internal(mi_bitmap_is_clearN(arena->slices_committed, slice_index, slice_count));
+    bool decommitted = mi_arena_purge(arena, slice_index, slice_count); MI_UNUSED(decommitted);
+    mi_assert_internal(!decommitted || mi_bitmap_is_clearN(arena->slices_committed, slice_index, slice_count));
     // and reset the free range
     mi_bbitmap_setN(arena->slices_free, slice_index, slice_count);
     return true;
@@ -1495,8 +1501,8 @@ static bool mi_arena_try_purge_visitor(size_t slice_index, size_t slice_count, m
       vinfo->all_purged = vinfo->all_purged && purged;
     }
   }
-  // done: clear the purge bits
-  mi_bitmap_clearN(arena->slices_purge, slice_index, slice_count);
+  // don't clear the purge bits as that is done atomically be the _bitmap_forall_set_ranges
+  // mi_bitmap_clearN(arena->slices_purge, slice_index, slice_count);
   return true; // continue
 }
 
@@ -1520,17 +1526,11 @@ static bool mi_arena_try_purge(mi_arena_t* arena, mi_msecs_t now, bool force)
   _mi_stat_counter_increase(&_mi_stats_main.arena_purges, 1);
 
   // go through all purge info's  (with max MI_BFIELD_BITS ranges at a time)
+  // this also clears those ranges atomically (so any newly freed blocks will get purged next
+  // time around)
   mi_purge_visit_info_t vinfo = { now, mi_arena_purge_delay(), true /*all?*/, false /*any?*/};
-  _mi_bitmap_forall_set_ranges(arena->slices_purge, &mi_arena_try_purge_visitor, arena, &vinfo);
+  _mi_bitmap_forall_setc_ranges(arena->slices_purge, &mi_arena_try_purge_visitor, arena, &vinfo);
 
-  // if not fully purged, make sure to purge again in the future
-  if (!vinfo.all_purged) {
-    const long delay = mi_arena_purge_delay();
-    mi_msecs_t expected = 0;
-    if (mi_atomic_casi64_strong_acq_rel(&arena->purge_expire, &expected, _mi_clock_now() + delay)) {
-      mi_atomic_storei64_release(&arena->purge_expire_extend, (mi_msecs_t)0);
-    }
-  }
   return vinfo.any_purged;
 }
 
diff --git a/src/bitmap.c b/src/bitmap.c
index 5734b9f5..71e54ba9 100644
--- a/src/bitmap.c
+++ b/src/bitmap.c
@@ -1239,9 +1239,10 @@ bool _mi_bitmap_forall_set(mi_bitmap_t* bitmap, mi_forall_set_fun_t* visit, mi_a
 }
 
 // Visit all set bits in a bitmap but try to return ranges (within bfields) if possible.
-// used by purging to purge larger ranges if possible
+// Also clear those ranges atomically.
+// Used by purging to purge larger ranges when possible
 // todo: optimize further? maybe use avx512 to directly get all indices using a mask_compressstore?
-bool _mi_bitmap_forall_set_ranges(mi_bitmap_t* bitmap, mi_forall_set_fun_t* visit, mi_arena_t* arena, void* arg) {
+bool _mi_bitmap_forall_setc_ranges(mi_bitmap_t* bitmap, mi_forall_set_fun_t* visit, mi_arena_t* arena, void* arg) {
   // for all chunkmap entries
   const size_t chunkmap_max = _mi_divide_up(mi_bitmap_chunk_count(bitmap), MI_BFIELD_BITS);
   for (size_t i = 0; i < chunkmap_max; i++) {
@@ -1254,7 +1255,7 @@ bool _mi_bitmap_forall_set_ranges(mi_bitmap_t* bitmap, mi_forall_set_fun_t* visi
       mi_bchunk_t* const chunk = &bitmap->chunks[chunk_idx];
       for (size_t j = 0; j < MI_BCHUNK_FIELDS; j++) {
         const size_t base_idx = (chunk_idx*MI_BCHUNK_BITS) + (j*MI_BFIELD_BITS);
-        mi_bfield_t b = mi_atomic_load_relaxed(&chunk->bfields[j]);
+        mi_bfield_t b = mi_atomic_exchange_acq_rel(&chunk->bfields[j], 0); // can be relaxed?
         #if MI_DEBUG > 1
         const size_t bpopcount = mi_popcount(b);
         size_t rngcount = 0;
diff --git a/src/bitmap.h b/src/bitmap.h
index 4faaa3a1..ed37e975 100644
--- a/src/bitmap.h
+++ b/src/bitmap.h
@@ -204,7 +204,7 @@ typedef bool (mi_forall_set_fun_t)(size_t slice_index, size_t slice_count, mi_ar
 bool _mi_bitmap_forall_set(mi_bitmap_t* bitmap, mi_forall_set_fun_t* visit, mi_arena_t* arena, void* arg);
 
 // Visit all set bits in a bitmap with larger ranges if possible (`slice_count >= 1`)
-bool _mi_bitmap_forall_set_ranges(mi_bitmap_t* bitmap, mi_forall_set_fun_t* visit, mi_arena_t* arena, void* arg);
+bool _mi_bitmap_forall_setc_ranges(mi_bitmap_t* bitmap, mi_forall_set_fun_t* visit, mi_arena_t* arena, void* arg);
 
 
 /* ----------------------------------------------------------------------------
diff --git a/src/stats.c b/src/stats.c
index 860a69ef..53937330 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -26,7 +26,7 @@ static bool mi_is_in_main(void* stat) {
 
 static void mi_stat_update(mi_stat_count_t* stat, int64_t amount) {
   if (amount == 0) return;
-  if (mi_is_in_main(stat))
+  if mi_unlikely(mi_is_in_main(stat))
   {
     // add atomically (for abandoned pages)
     int64_t current = mi_atomic_addi64_relaxed(&stat->current, amount);
@@ -51,6 +51,27 @@ static void mi_stat_update(mi_stat_count_t* stat, int64_t amount) {
   }
 }
 
+// Adjust stats to compensate; for example before committing a range,
+// first adjust downwards with parts that were already committed so 
+// we avoid double counting.
+static void mi_stat_adjust(mi_stat_count_t* stat, int64_t amount) {
+  if (amount == 0) return;
+  if mi_unlikely(mi_is_in_main(stat))
+  {
+    // adjust atomically 
+    mi_atomic_addi64_relaxed(&stat->current, amount);
+    mi_atomic_addi64_relaxed(&stat->allocated, amount);
+    mi_atomic_addi64_relaxed(&stat->freed, amount);
+  }
+  else {
+    // don't affect the peak
+    stat->current += amount;    
+    // add to both
+    stat->allocated += amount;
+    stat->freed += amount;    
+  }
+}
+
 void _mi_stat_counter_increase(mi_stat_counter_t* stat, size_t amount) {
   if (mi_is_in_main(stat)) {
     mi_atomic_addi64_relaxed( &stat->count, 1 );
@@ -70,6 +91,14 @@ void _mi_stat_decrease(mi_stat_count_t* stat, size_t amount) {
   mi_stat_update(stat, -((int64_t)amount));
 }
 
+void _mi_stat_adjust_increase(mi_stat_count_t* stat, size_t amount) {
+  mi_stat_adjust(stat, (int64_t)amount);
+}
+
+void _mi_stat_adjust_decrease(mi_stat_count_t* stat, size_t amount) {
+  mi_stat_adjust(stat, -((int64_t)amount));
+}
+
 // must be thread safe as it is called from stats_merge
 static void mi_stat_add(mi_stat_count_t* stat, const mi_stat_count_t* src, int64_t unit) {
   if (stat==src) return;