// is to avoid excessive malloc() and free() overhead.
Segment* head = Segment::head();
int old_size = (head == NULL) ? 0 : head->size();
- int new_size = sizeof(Segment) + kAlignment + size + (old_size << 1);
- if (new_size < kMinimumSegmentSize) new_size = kMinimumSegmentSize;
+ static const int kSegmentOverhead = sizeof(Segment) + kAlignment;
+ int new_size = kSegmentOverhead + size + (old_size << 1);
+ if (new_size < kMinimumSegmentSize) {
+ new_size = kMinimumSegmentSize;
+ } else if (new_size > kMaximumSegmentSize) {
+ // Limit the size of new segments to avoid growing the segment size
+ // exponentially, thus putting pressure on contiguous virtual address
+ // space.
+ if (size > (kMaximumSegmentSize - kSegmentOverhead)) {
+ // Make sure to allocate a segment at large enough to hold the requested
+ // size.
+ new_size = kSegmentOverhead + size;
+ } else {
+ // Allocate a new segment of maximum size.
+ new_size = kMaximumSegmentSize;
+ }
+ }
Segment* segment = Segment::New(new_size);
if (segment == NULL) V8::FatalProcessOutOfMemory("Zone");
// Never allocate segments smaller than this size in bytes.
static const int kMinimumSegmentSize = 8 * KB;
+
+ // Never allocate segments larger than this size in bytes.
+ static const int kMaximumSegmentSize = 1 * MB;
// Never keep segments larger than this size in bytes around.
static const int kMaximumKeptSegmentSize = 64 * KB;