public long determineMaxMmSize(long defragHeadroom, long maxMmSize) {
    if (defragHeadroom > 0) {
      long maxHeadroom = (long) Math.floor(maxSize * MAX_DEFRAG_HEADROOM_FRACTION);
      defragHeadroom = Math.min(maxHeadroom, defragHeadroom);
      LlapIoImpl.LOG.info("Leaving " + defragHeadroom + " of defragmentation headroom");
      maxMmSize -= defragHeadroom;
    }
    return maxMmSize;
  }
Default max amount of bytes to force evict on failed allocation attempts 16MB. used for testing, for production
please adjust {@link ConfVars.LLAP_ALLOCATOR_MAX_FORCE_EVICTED}
llap-server/src/java/org/apache/hadoop/hive/llap/cache/BuddyAllocator.java