This change set disables creation of the monitor thread by default.  The global
counter maintained by the monitor thread was replaced by logic that uses system
time directly, and cyclic yielding on Linux target was also removed since there
was no clear benefit of using it. Turning on KMP_USE_MONITOR variable (=1)
enables creation of monitor thread again if it is really necessary for some
reasons.

Differential Revision: https://reviews.llvm.org/D24739

llvm-svn: 282507

When linking with libhwloc, the ORDERED EPCC test slows down on big
machines (> 48 cores). Performance analysis showed that a cache thrash
was occurring and this padding helps alleviate the problem.

Also, inside the main spin-wait loop in kmp_wait_release.h, we can eliminate
the references to the global shared variables by instead creating a local
variable, oversubscribed and instead checking that.

Differential Revision: http://reviews.llvm.org/D22093

llvm-svn: 274894

This patch doesn't affect D19878's context.  So D19878 still cleanly applies.

llvm-svn: 270252

This reverts a presumaby-unintentional change in:

  r268640 - [STATS] Use partitioned timer scheme

and fixes segfaults in an x86_64 debug build of the runtime library.

llvm-svn: 269259

This change removes the current timers with ones that partition time properly.
The current timers are nested, so that if a new timer, B, starts when the
current timer, A, is already timing, A's time will include B's. To eliminate
this problem, the partitioned timers are designed to stop the current timer (A),
let the new timer run (B), and when the new timer is finished, restart the
previously running timer (A). With this partitioning of time, a threads' timers
all sum up to the OMP_worker_thread_life time and can now easily show the
percentage of time a thread is spending in different parts of the runtime or
user code.

There is also a new state variable associated with each thread which tells where
it is executing a task. This corresponds with the timers: OMP_task_*, e.g., if
time is spent in OMP_task_taskwait, then that thread executed tasks inside a
#pragma omp taskwait construct.

The changes are mostly changing the MACROs to use the new PARITIONED_* macros,
the new partitionedTimers class and its methods, and new state logic.

Differential Revision: http://reviews.llvm.org/D19229

llvm-svn: 268640

Removed reference to "ref ct" in a comment, as ref_ct no longer exists. Also
moved the comment to where the task_team is about to be tested if NULL.

llvm-svn: 264786

llvm-svn: 257378

llvm-svn: 256060

1) Add get_ptr_type() method to all wait flag types.
2) Flag in sleep_loc may change type by the time the resume is called from
   __kmp_null_resume_wrapper. We use get_ptr_type to obtain the real type
   and compare it to the casted object received. If they don't match, we know
   the flag has changed (already resumed and replaced by another flag). If they
   match, it doesn't hurt to go ahead and resume it.

Differential Revision: http://reviews.llvm.org/D14458

llvm-svn: 252487

This is a refactoring of the task_team code that more elegantly handles the two
task_team case. Two task_teams per team are kept in use for the lifetime of the
team. Thus no reference counting is needed.

Differential Revision: http://reviews.llvm.org/D13993

llvm-svn: 252082

llvm-svn: 249725

These changes improve/update the trace messages and debug asserts related to
the previous wait/release checkin.

llvm-svn: 249717

These changes improve the wait/release mechanism for threads spinning in 
barriers that are handling tasks while spinnin by providing feedback to the 
barriers about any task stealing that occurs.

Differential Revision: http://reviews.llvm.org/D13353

llvm-svn: 249711

Prior to this change, OMPT had a status flag ompt_status, which could take
several values. This was due to an earlier OMPT design that had several levels
of enablement (ready, disabled, tracking state, tracking callbacks). The
current OMPT design has OMPT support either on or off.
This revision replaces ompt_status with a boolean flag ompt_enabled, which 
simplifies the runtime logic for OMPT.

Patch by John Mellor-Crummey

Differential Revision: http://reviews.llvm.org/D12999

llvm-svn: 248189

This only triggered when built in debug mode with OMPT enabled:
__kmp_wait_template expected the state of the current thread to be either
ompt_state_idle or ompt_state_wait_barrier{,_implicit,_explicit}.

Patch by Jonas Hahnfeld

Differential Revision: http://reviews.llvm.org/D12754

llvm-svn: 247339

This change changes kmp_bstate.old_tid to sign integer instead of unsigned integer.
It also defines two new macros KMP_NSEC_PER_SEC and KMP_USEC_PER_SEC which lets us take
control of the sign (we want them to be longs).  Also, in kmp_wait_release.h, the byteref()
function's return type is changed from char to unsigned char.

llvm-svn: 239057

in kmp_wait_release.h, there were some constructors where the initialization
lists were out of order with the member declarations inside the class.  This
patch just reorders the initialization list so the compiler doesn't complain.
http://lists.cs.uiuc.edu/pipermail/openmp-dev/2015-June/000670.html

Patch by Jack Howarth and Jonathan Peyton

llvm-svn: 238946

These are the actual changes in the runtime to issue OMPT-related functions. All of them are surrounded by #if OMPT_SUPPORT and can be disabled (which is the default).

llvm-svn: 236122

llvm-svn: 228718

llvm-svn: 227207

understand that this is not friendly, and are working to change our
internal code-development to make it easier to make development
features available more frequently and in finer (more functional)
chunks. Unfortunately we haven't got that in place yet, and unpicking
this into multiple separate check-ins would be non-trivial, so please
bear with me on this one. We should be better in the future.

Apologies over, what do we have here?

GGC 4.9 compatibility
--------------------
* We have implemented the new entrypoints used by code compiled by GCC
4.9 to implement the same functionality in gcc 4.8. Therefore code
compiled with gcc 4.9 that used to work will continue to do so.
However, there are some other new entrypoints (associated with task
cancellation) which are not implemented. Therefore user code compiled
by gcc 4.9 that uses these new features will not link against the LLVM
runtime. (It remains unclear how to handle those entrypoints, since
the GCC interface has potentially unpleasant performance implications
for join barriers even when cancellation is not used)

--- new parallel entry points ---
new entry points that aren't OpenMP 4.0 related
These are implemented fully :-
      GOMP_parallel_loop_dynamic()
      GOMP_parallel_loop_guided()
      GOMP_parallel_loop_runtime()
      GOMP_parallel_loop_static()
      GOMP_parallel_sections()
      GOMP_parallel()

--- cancellation entry points ---
Currently, these only give a runtime error if OMP_CANCELLATION is true
because our plain barriers don't check for cancellation while waiting
        GOMP_barrier_cancel()
        GOMP_cancel()
        GOMP_cancellation_point()
        GOMP_loop_end_cancel()
        GOMP_sections_end_cancel()

--- taskgroup entry points ---
These are implemented fully.
      GOMP_taskgroup_start()
      GOMP_taskgroup_end()

--- target entry points ---
These are empty (as they are in libgomp)
     GOMP_target()
     GOMP_target_data()
     GOMP_target_end_data()
     GOMP_target_update()
     GOMP_teams()

Improvements in Barriers and Fork/Join
--------------------------------------
* Barrier and fork/join code is now in its own file (which makes it
easier to understand and modify).
* Wait/release code is now templated and in its own file; suspend/resume code is also templated
* There's a new, hierarchical, barrier, which exploits the
cache-hierarchy of the Intel(r) Xeon Phi(tm) coprocessor to improve
fork/join and barrier performance.

***BEWARE*** the new source files have *not* been added to the legacy
Cmake build system. If you want to use that fixes wil be required.

Statistics Collection Code
--------------------------
* New code has been added to collect application statistics (if this
is enabled at library compile time; by default it is not). The
statistics code itself is generally useful, the lightweight timing
code uses the X86 rdtsc instruction, so will require changes for other
architectures.
The intent of this code is not for users to tune their codes but
rather 
1) For timing code-paths inside the runtime
2) For gathering general properties of OpenMP codes to focus attention
on which OpenMP features are most used. 

Nested Hot Teams
----------------
* The runtime now maintains more state to reduce the overhead of
creating and destroying inner parallel teams. This improves the
performance of code that repeatedly uses nested parallelism with the
same resource allocation. Set the new KMP_HOT_TEAMS_MAX_LEVEL
envirable to a depth to enable this (and, of course, OMP_NESTED=true
to enable nested parallelism at all).

Improved Intel(r) VTune(Tm) Amplifier support
---------------------------------------------
* The runtime provides additional information to Vtune via the
itt_notify interface to allow it to display better OpenMP specific
analyses of load-imbalance.

Support for OpenMP Composite Statements
---------------------------------------
* Implement new entrypoints required by some of the OpenMP 4.1
composite statements.

Improved ifdefs
---------------
* More separation of concepts ("Does this platform do X?") from
platforms ("Are we compiling for platform Y?"), which should simplify
future porting.


ScaleMP* contribution
---------------------
Stack padding to improve the performance in their environment where
cross-node coherency is managed at the page level.

Redesign of wait and release code
---------------------------------
The code is simplified and performance improved.

Bug Fixes
---------
    *Fixes for Windows multiple processor groups.
    *Fix Fortran module build on Linux: offload attribute added.
    *Fix entry names for distribute-parallel-loop construct to be consistent with the compiler codegen.
    *Fix an inconsistent error message for KMP_PLACE_THREADS environment variable.

llvm-svn: 219214