diff --git a/src/segment-cache.c b/src/segment-cache.c
index 6f9d5fcb..eeae1b50 100644
--- a/src/segment-cache.c
+++ b/src/segment-cache.c
@@ -216,20 +216,27 @@ mi_decl_noinline bool _mi_segment_cache_push(void* start, size_t size, size_t me
   return false;
 #else
 
-  // only for normal segment blocks
+  // purge expired entries
+  mi_segment_cache_purge(false /* limit purges to a constant N */, false /* don't force unexpired */, tld);
+
+  // only cache normal segment blocks
   if (size != MI_SEGMENT_SIZE || ((uintptr_t)start % MI_SEGMENT_ALIGN) != 0) return false;
 
+  // Also do not cache arena allocated segments that cannot be decommitted. (as arena allocation is fast)
+  // This is a common case with reserved huge OS pages.
+  // 
+  // (note: we could also allow segments that are already fully decommitted but that never happens
+  //  as the first slice is always committed (for the segment metadata))
+  if (!_mi_arena_is_os_allocated(memid) && is_pinned) return false;
+
   // numa node determines start field
   int numa_node = _mi_os_numa_node(NULL);
   size_t start_field = 0;
   if (numa_node > 0) {
-    start_field = (MI_CACHE_FIELDS / _mi_os_numa_node_count())*numa_node;
+    start_field = (MI_CACHE_FIELDS / _mi_os_numa_node_count()) * numa_node;
     if (start_field >= MI_CACHE_FIELDS) start_field = 0;
   }
 
-  // purge expired entries
-  mi_segment_cache_purge(false /* limit purges to a constant N */, false /* don't force unexpired */, tld);
-
   // find an available slot
   mi_bitmap_index_t bitidx;
   bool claimed = _mi_bitmap_try_find_from_claim(cache_inuse, MI_CACHE_FIELDS, start_field, 1, &bitidx);
diff --git a/src/segment.c b/src/segment.c
index f8a5d6a0..dc25dbda 100644
--- a/src/segment.c
+++ b/src/segment.c
@@ -397,8 +397,10 @@ static void mi_segment_os_free(mi_segment_t* segment, mi_segments_tld_t* tld) {
   if (size != MI_SEGMENT_SIZE || segment->mem_align_offset != 0 || segment->kind == MI_SEGMENT_HUGE || // only push regular segments on the cache
        !_mi_segment_cache_push(segment, size, segment->memid, &segment->commit_mask, &segment->decommit_mask, segment->mem_is_large, segment->mem_is_pinned, tld->os)) 
   {
-    const size_t csize = _mi_commit_mask_committed_size(&segment->commit_mask, size);
-    if (csize > 0 && !segment->mem_is_pinned) _mi_stat_decrease(&_mi_stats_main.committed, csize);
+    if (!segment->mem_is_pinned) {
+      const size_t csize = _mi_commit_mask_committed_size(&segment->commit_mask, size);
+      if (csize > 0) { _mi_stat_decrease(&_mi_stats_main.committed, csize); }
+    }
     _mi_abandoned_await_readers();  // wait until safe to free
     _mi_arena_free(segment, mi_segment_size(segment), segment->mem_alignment, segment->mem_align_offset, segment->memid, segment->mem_is_pinned /* pretend not committed to not double count decommits */, tld->stats);
   }