@@ -658,7 +658,7 @@ heap_trim (heap_info *heap, size_t pad)
unsigned long pagesz = GLRO (dl_pagesize);
mchunkptr top_chunk = top (ar_ptr), p, bck, fwd;
heap_info *prev_heap;
- long new_size, top_size, extra, prev_size, misalign;
+ long new_size, top_size, top_area, extra, prev_size, misalign;
/* Can this heap go away completely? */
while (top_chunk == chunk_at_offset (heap, sizeof (*heap)))
@@ -694,9 +694,16 @@ heap_trim (heap_info *heap, size_t pad)
set_head (top_chunk, new_size | PREV_INUSE);
/*check_chunk(ar_ptr, top_chunk);*/
}
+
+ /* Uses similar logic for per-thread arenas as the main arena with systrim
+ by preserving the top pad and at least a page. */
top_size = chunksize (top_chunk);
- extra = (top_size - pad - MINSIZE - 1) & ~(pagesz - 1);
- if (extra < (long) pagesz)
+ top_area = top_size - MINSIZE - 1;
+ if (top_area <= pad)
+ return 0;
+
+ extra = (top_area - pad) & ~(pagesz - 1);
+ if ((unsigned long) extra < mp_.trim_threshold)
return 0;
/* Try to shrink. */