title: How to trace "tcmalloc : large alloc .... "
body: <p>my app print several line like:</p>
  
  <pre><code>tcmalloc: large alloc 4294488064 bytes == 0x2b968d8000 @  0x727432 0x727302 0x727a58    0x75a07d 0x574beb 0x585756 0x5575df 0x5717db 0x57108f 0x58078c 0x302b80610a
  tcmalloc: large alloc 4294488064 bytes == 0x2c97063000 @  0x727432 0x727302 0x727a58   0x75a07d 0x574beb 0x585756 0x5575df 0x5717db 0x57108f 0x58078c 0x302b80610a
  tcmalloc: large alloc 4294488064 bytes == 0x2b968d8000 @  0x727432 0x727302 0x727a58 0x75a07d 0x574beb 0x585756 0x5575df 0x5717db 0x57108f 0x58078c 0x302b80610a
  </code></pre>
  
  <p>where does this message comes from? does it means my app has some bugs or memory-leak? how can I trace the root cause?</p>