Code review request: CR 6995781 Native Memory Tracking Phase 1

[Zhengyu Gu]

This is the webrev for native memory tracking phase 1, which is tracked 
by CR6995781 (http://monaco.us.oracle.com/detail.jsf?cr=6995781) and 
related DCmd CR7151532 (http://monaco.us.oracle.com/detail.jsf?cr=7151532).

Native memory tracking (NMT) phase 1, is designed to track native memory 
(malloc'd and mmap'd) usages by VM code only, it does not track the 
memory usages by libraries and JNI code.

On the implementation side, NMT intercepts memory related calls in os 
implementation, such as os::malloc, os::realloc, os::free, 
os::reserve_memory, os::commit_memory and etc. the caller is required to 
provide the 'memory type' information, which represents the VM subsystem 
that the memory is allocated for. The 'memory type' is defined in 
/src/share/memory/allocation.hpp. Also, a caller's pc is captured if NMT 
tracking level is set to detail.

There are a few ways to tag a memory block to a memory type:

1. os::malloc takes an extra parameter for the memory type.
2. CHeapObj now is a template, it takes a memory type as template 
parameter to tag the object to a specified memory type.
3. Utility classes, such as Arena, GrowableArray and etc. the memory 
type is a parameter of 'new' operator.
4. Virtual memory block is tagged on its base address.

When NMT intercepts the call, a memory record is created and serialized 
by a sequence number, generated by global sequence generator. The memory 
record is written to a per-thread recorder without a  lock, when calling 
thread is a 'safepoint visible' JavaThread - a JavaThread that will 
block at safepoint. Otherwise, ThreadCritical lock is acquired to write 
to a global recorder. The recorders (or raw data) are synchronized at 
some safepoints, and global sequence generator is also reset at 
synchronization time, to avoid overflow the sequence number.

A dedicated NMT worker thread is created to process the raw memory 
records. It first stages a generation of raw data (a generation is 
defined as span between resets of global sequence number), then promotes 
the staged data to a global snapshot, which maintains information of all 
'live' memory block.

NMT Tracking option has to be specified through VM command line option 
-XX:NativeMemoryTracking (off by default), tracking level can not be 
altered during runtime, but it can be shutdown through jcmd tool.

NMT DCmd implements a set of sub-command to control NMT runtime and 
request tracking data.

Webrev: http://cr.openjdk.java.net/~zgu/6995781/webrev.00

The tests and results:

  - Passed internal smoke tests
  - JTreg test: http://cr.openjdk.java.net/~zgu/6995781/JTreport/


Additional notes:
   - Some classes' new operators are marked _NOINLINE_ (for the same 
purpose as above), the performance runs, I performed, indicate that they 
do not impact performance numbers.

   - SA agent changes are in progress

Thanks,

-Zhengyu