Users can now pass --enable-mpit-pvars to configure to statically
enable/disable MPIT performance variables so as to limit performance
impacts only to those variables they need.

Current valid arguments are as follows:
    none     - No performance info recorded
    recvq    - All message queue-related variables
    nem      - All nemesis-related variables
    all      - All variables above

A macro framework is added to facilitate the addition of new variables
(see MPIR_T_GATE on mpid_common_statistics.h).

Also add a check to the MPIT nemesis test to ensure that the variables
being tested have been registered with the runtime.

The following MPIT performance variables are added:

 - nem_fbox_fall_back_to_queue_count;
 - time_failed_matching_postedq;
 - time_matching_unexpectedq;
 - unexpected_recvq_buffer_size.

Some common MPIT-related routines, handle creation functions and
enable/disable switches are gathered in a common file.

Two test cases are furnished, but not yet integrated with 'make check'.

This commit implements MPI-3 RMA's flush and flush_all operations.

Reviewer: buntinas

When enabled, this mode of operation immediately requests the lock when
MPI_Win_lock is called.  Currently, this is enabled by setting the
MPICH_RMA_LOCK_IMMED environment variable.  In the future, we can also make
this mode of operation available though an info/assert.  This capability is
needed to implement MPI-3's flush operations.

Reviewer: buntinas

Reviewer: goodell

By setting "indent-tabs-mode:nil" we should hopefully begin to slowly
squeeze out hard tabs from the source without a disruptive (to
downstream projects) whitespace-fixing change.

No reviewer.

Updated the fetch_and_op implementation to have two data transfer paths; one
where data can be embedded in the packet header and one where it is sent
separately.  With this change, the header size is back to 40 bytes.

Reviewer: buntinas

Adds implementation of atomic fetch-and-op operation and several test cases.

Reviewer: buntinas

The source_win_handle is used to inform the target that the RMA access epoch
has ended.  This was removed from the CAS packet to save space and was replaced
with another packet type, MPIDI_CH3_PKT_CAS_UNLOCK, which conveys the same
information.

This patch adds support for the new MPI-3 compare-and-swap routine.  The
implementation embeds the data into the packet header to reduce the number of
messages.

Reviewer: buntinas

Moved RMA implementation constants from mpidimpl.h to the RMA implementation
header.  Also updated constants to use enumeration types and removed an old
fixme note, which indicated that this should be done.

Reviewer: buntinas

[svn-r7416] Major improvement to RMA performance for long lists of operations, an immediate mode accumulate for single ints, store the MPID_Comm within the window, and added a basic performance instrumentation interface that was extensively used to improve the RMA performance (enabled with --enable-g=instr).  With these fixes, MPICH2 can run the one-sided version of the Graph500 benchmark at a respectable if not great rate

[svn-r7312] Correct use of MPI_ERR_NO_MEM (should be MPI_ERR_OTHER) for out-of-memory that does not pertain to MPI_Alloc_mem and add detail to error messages about out-of-memory

[svn-r3296] Added message about number of reqs in unexpected buffer when we fail to allocate a request for an unexpected message.  This is a more informative message so the user can see why a request was unable to be allocated.

[svn-r3271] Committing the 64-bit optimization code for queue searching. This should make queue searches for the posted queue and the unexpected queue considerably faster for large queue lengths. Reviewed by
buntinas.

[svn-r3070] Added ATTRIBUTE((unused)) (which is defined to work with gcc and disappear for other compilers only to the functions whose arguments are defined by a general pattern (such as a request handler) and thus must be used even if not needed.  For functions that have parameters that are not used and are not needed to conform to a pattern, do not use ATTRIBUTE((unused)), instead, fix the routine to either make use of the argument in a real way or change the routine to not pass the argument.

[svn-r477] Initializing some additional variables during their declaration. This doesn't hurt MPICH2, but eases OSU's MVAPICH2 integration.