JDK-8061996 : NMT2 overflows MallocSiteTable too much
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 9
  • Priority: P4
  • Status: Closed
  • Resolution: Won't Fix
  • Submitted: 2014-10-23
  • Updated: 2015-03-09
  • Resolved: 2015-03-09
Related Reports
Relates :  
Description
Several bugs have been found where the MallocSiteTable is overflowed.  The index to the table might be 128 or some non-prime number.  This should be improved.
Comments
Found the other bug that caused this, we'll not change the hash. Closing as WNF
09-03-2015

// Currently, (number of buckets / number of entires) ratio is // about 1 / 6 enum { table_base_size = 128, // The base size is calculated from statistics to give // table ratio around 1:6 table_size = (table_base_size * NMT_TrackingStackDepth - 1) }; NMT_TrackingStackDepth = 4, so the table size is 511, which is divisible by 7. ATM we only have stress tests that overflow the table though.
15-12-2014