[zone] Fix zone segment pooling size limits

src/zone/accounting-allocator.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/zone/accounting-allocator.h"
 
 #include <cstdlib>
 
 #if V8_LIBC_BIONIC
 #include <malloc.h>  // NOLINT
@@ skipping 41 matching lines @@
   // This code will work best if the max_pool_size is a multiple of the
   // full_size. If max_pool_size is no sum of segment sizes the actual pool
   // size might be smaller then max_pool_size. Note that no actual memory gets
   // wasted though.
   // TODO(heimbuef): Determine better strategy generating a segment sizes
   // distribution that is closer to real/benchmark usecases and uses the given
   // max_pool_size more efficiently.
   size_t total_size = fits_fully * full_size;
 
   for (size_t power = 0; power < kNumberBuckets; ++power) {
-    if (total_size + (size_t(1) << power) <= max_pool_size) {
+    if (total_size + (size_t(1) << (power + kMinSegmentSizePower)) <=
+        max_pool_size) {
       unused_segments_max_sizes_[power] = fits_fully + 1;
       total_size += size_t(1) << power;
     } else {
       unused_segments_max_sizes_[power] = fits_fully;
     }
   }
 }
 
 Segment* AccountingAllocator::GetSegment(size_t bytes) {
   Segment* result = GetSegmentFromPool(bytes);
@@ skipping 120 matching lines @@
       Segment* next = current->next();
       FreeSegment(current);
       current = next;
     }
     unused_segments_heads_[power] = nullptr;
   }
 }
 
 }  // namespace internal
 }  // namespace v8