IV62211: CRASH WITH ASSERTION FAILED AT MGCALLOC.CPP:453

APAR status

• Closed as program error.

Error description

• Error Message: An assertion triggers with the line:j9mm.107    *
  ** ASSERTION FAILED ** at mgcalloc.cpp:453: ((false &&
  (extensions->isOld(objectPtr))))The line number (453 in this
  case) may be different.
  .
  Stack Trace: J9AllocateObjectNoGCorJ9AllocateObjectwill be on
  the top of the stack and this assertion should appear:j9mm.107
   *   ** ASSERTION FAILED ** at mgcalloc.cpp:453: ((false &&
  (extensions->isOld(objectPtr))))The line number (453 in this
  case) may be different.
  .
  n/a
  

Local fix

• There is no true workaround for this but it is possible to
  decrease the odds of this problem occurring.  This problem only
  happens if there is a lot of heap pressure in tenure space.So
  this can be mitigated by increasing the amount of tenure heap.
  i.e. set -Xmx, -Xms to a larger number.  Note the circumstances
  for this problem to occur requires a situation where an
  OutOfMemoryError is imminent.
  

Problem summary

• The problem occurs as a result of a flaw in the allocation logic
  such that an attempt to tenure-allocate may result in a nursery
  allocation if tenure is full after a global GC.  This causes
  various problems because certain types of objects (such as
  interned strings and class objects) must be tenure-allocated.  A
  failure to do this may lead to the objects being collected
  prematurely.Later versions of the JVM include an assert (the one
  described in the error message) to catch this problem.
  

Problem conclusion

• The JVM has been updated to never nursery-allocate if
  tenure-allocation is specified.
  .
  This APAR will be fixed in the following Java Releases:
     6 R1 SR8 FP1   (6.1.8.1)
     7 R1 SR1 FP1   (7.1.1.1)
     7    SR7 FP1   (7.0.7.1)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, Java maintenance is available
  from:
             https://www.ibm.com/developerworks/java/jdk/
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  J9 COMMON CODE

• Fixed component ID

  620700127

Applicable component levels

• R260 PSY

     UP

• R270 PSY

     UP