The __kmp_execute_tasks_template() function reads the task_team and
current_task from the thread structure. There appears to be a pathological
timing where the number of threads in the hot team decreases and so a
thread is put in the pool via __kmp_free_thread(). It could be the case that:
1) A thread reads th_task_team into task_team local variables
and is then interrupted by the OS
2) Master frees the thread and sets current task and task team to NULL
3) The thread reads current_task as NULL
When this happens, current_task is dereferenced and a segfault occurs.
This patch just checks for current_task to not be NULL as well.
Differential Revision: https://reviews.llvm.org/D50651
llvm-svn: 340632
If hot teams are not being used, this code could seg fault without the added
check, and does so when composability is used in conjunction with nesting.
The fix prevents the segfault.
Differential Revision: https://reviews.llvm.org/D50649
llvm-svn: 340629
Exclude nested explicit tasks from timing, only outer level explicit task
counted and its time added to barrier arrive time for the thread.
Differential Revision: https://reviews.llvm.org/D50584
llvm-svn: 340628
The idle callback was removed from the spec as of TR7.
This removes it from the implementation.
Patch provided by Simon Convent
Reviewers: hbae, protze.joachim
Differential Revision: https://reviews.llvm.org/D48362
llvm-svn: 339771
This change fixes an incorrect behavior of the omp_control_tool function when
called from Fortran applications. A tool callback function for this event is
supposed to get NULL for the third argument according to the specification, but
the current implementation just passes a garbage value. A possible fix is to use
the OPTIONAL attribute for the third argument.
Patch by Hansang Bae
Differential Revision: https://reviews.llvm.org/D50565
llvm-svn: 339585
This patch cleans up unused functions, variables, sign compare issues, and
addresses some -Warning flags which are now enabled including -Wcast-qual.
Not all the warning flags in LibompHandleFlags.cmake are enabled, but some
are with this patch.
Some __kmp_gtid_from_* macros in kmp.h are switched to static inline functions
which allows us to remove the awkward definition of KMP_DEBUG_ASSERT() and
KMP_ASSERT() macros which used the comma operator. This had to be done for the
innumerable -Wunused-value warnings related to KMP_DEBUG_ASSERT()
Differential Revision: https://reviews.llvm.org/D49105
llvm-svn: 339393
From the bug report, the runtime needs to initialize the nproc variables
(inside middle init) for each root when the task is encountered, otherwise,
a segfault can occur.
Bugzilla: https://bugs.llvm.org/show_bug.cgi?id=36720
Differential Revision: https://reviews.llvm.org/D49996
llvm-svn: 338313
Summary:
When OMPT is not supported the __kmp_omp_task() function is passed the parameters in the wrong order. This is a fix related to patch D47709.
Reviewers: Hahnfeld, sconvent, caomhin, jlpeyton
Reviewed By: Hahnfeld
Subscribers: guansong, openmp-commits
Differential Revision: https://reviews.llvm.org/D50001
llvm-svn: 338295
This change introduces GOMP doacross compatibility. There are 12 new interface
functions 6 for long type and 6 for unsigned long long type:
GOMP_doacross_post, GOMP_doacross_wait, GOMP_loop_doacross_[schedule]_start
where schedule can be static, dynamic, guided, or runtime.
These functions just translate the parameters if necessary and send them
to the corresponding kmp function.
E.g., GOMP_doacross_post() -> __kmpc_doacross_post()
For the GOMP_doacross_post function, there is template specialization to
account for when long is a four byte vs an eight byte type. If it is a
four byte type, then a temporary array has to be created to convert the
four byte integers into eight byte integers and then sending that into
__kmpc_doacross_post(). Because GOMP_doacross_wait uses varargs, it
always needs a temporary array and does not need template specialization.
Differential Revision: https://reviews.llvm.org/D49857
llvm-svn: 338280
This change fixes build errors when building a runtime with adaptive lock stats
enabled. Most of the errors were due to the recent changes in the runtime, but
it seems that we have not tried to build this debug runtime on Windows for a
long time.
Patch by Hansang Bae
Differential Revision: https://reviews.llvm.org/D49823
llvm-svn: 338277
1) Remove unnecessary data from list node structure
2) Remove timerPair in favor of pushing/popping explicitTimers.
This way, nested timers will work properly.
3) Fix #pragma omp critical timers
4) Add histogram capability
5) Add KMP_STATS_FILE formatting capability
6) Have time partitioned into serial & parallel by introducing
partitionedTimers::exchange(). This also counts the number of serial regions
in the executable.
7) Fix up the timers around OMP loops so that scheduling overhead and work are
both counted correctly.
8) Fix up the iterations statistics so they count the number of iterations the
thread receives at each loop scheduling event
9) Change timers so there is only one RDTSC read per event change
10) Fix up the outdated comments for the timers
Differential Revision: https://reviews.llvm.org/D49699
llvm-svn: 338276
Fix the order of callbacks related to the taskloop construct.
Add the iteration_count to work callbacks (according to the spec).
Use kmpc_omp_task() instead of kmp_omp_task() to include OMPT callbacks.
Add a testcase.
Patch by Simon Convent
Reviewed by: protze.joachim, hbae
Subscribers: openmp-commits
Differential Revision: https://reviews.llvm.org/D47709
llvm-svn: 338146
The ompt/tasks/task_types.c testcase did not test untied tasks properly. Now,
frame addresses are tested and two scheduling points are added at which the
task can switch to another thread. Due to scheduling effects, the frame address
could be NULL.
This needed a restructure of the way OMPT callbacks are called.
__ompt_task_finish() now as an extra parameter, whether a task is completed.
Its invocation has been moved into __kmp_task_finish(). Thus, the order of the
writes to the frame addresses is not subject to scheduling effects anymore.
Patch by Simon Convent
Reviewed by: protze.joachim, hbae
Subscribers: openmp-commits
Differential Revision: https://reviews.llvm.org/D49181
llvm-svn: 338145
This function was not enabled by default and not exported when manually
tweaking the build flags. Additionally it was hard to use since there
is no corresponding __kmp_ft_page_free().
The code itself is questionable because the returned memory address
is padded by an extra pointer which stores the unpadded start of the
allocated region (this would need to be freed).
Differential Revision: https://reviews.llvm.org/D49802
llvm-svn: 338052
This change fixes possibly invalid access to the internal data structure during
library shutdown. In a heavily oversubscribed situation, the library shutdown
sequence can reach the point where resources are deallocated while there still
exist threads in their final spinning loop. The added loop in
__kmp_internal_end() checks if there are such busy-waiting threads and blocks
the shutdown sequence if that is the case. Two versions of kmp_wait_template()
are now used to minimize performance impact.
Patch by Hansang Bae
Differential Revision: https://reviews.llvm.org/D49452
llvm-svn: 337486
This patch introduces the logic implementing hierarchical scheduling.
First and foremost, hierarchical scheduling is off by default
To enable, use -DLIBOMP_USE_HIER_SCHED=On during CMake's configure stage.
This work is based off if the IWOMP paper:
"Workstealing and Nested Parallelism in SMP Systems"
Hierarchical scheduling is the layering of OpenMP schedules for different layers
of the memory hierarchy. One can have multiple layers between the threads and
the global iterations space. The threads will go up the hierarchy to grab
iterations, using possibly a different schedule & chunk for each layer.
[ Global iteration space (0-999) ]
(use static)
[ L1 | L1 | L1 | L1 ]
(use dynamic,1)
[ T0 T1 | T2 T3 | T4 T5 | T6 T7 ]
In the example shown above, there are 8 threads and 4 L1 caches begin targeted.
If the topology indicates that there are two threads per core, then two
consecutive threads will share the data of one L1 cache unit. This example
would have the iteration space (0-999) split statically across the four L1
caches (so the first L1 would get (0-249), the second would get (250-499), etc).
Then the threads will use a dynamic,1 schedule to grab iterations from the L1
cache units. There are currently four supported layers: L1, L2, L3, NUMA
OMP_SCHEDULE can now read a hierarchical schedule with this syntax:
OMP_SCHEDULE='EXPERIMENTAL LAYER,SCHED[,CHUNK][:LAYER,SCHED[,CHUNK]...]:SCHED,CHUNK
And OMP_SCHEDULE can still read the normal SCHED,CHUNK syntax from before
I've kept most of the hierarchical scheduling logic inside kmp_dispatch_hier.h
to try to keep it separate from the rest of the code.
Differential Revision: https://reviews.llvm.org/D47962
llvm-svn: 336571
This patch reorganizes the loop scheduling code in order to allow hierarchical
scheduling to use it more effectively. In particular, the goal of this patch
is to separate the algorithmic parts of the scheduling from the thread
logistics code.
Moves declarations & structures to kmp_dispatch.h for easier access in
other files. Extracts the algorithmic part of __kmp_dispatch_init() and
__kmp_dispatch_next() into __kmp_dispatch_init_algorithm() and
__kmp_dispatch_next_algorithm(). The thread bookkeeping logic is still kept in
__kmp_dispatch_init() and __kmp_dispatch_next(). This is done because the
hierarchical scheduler needs to access the scheduling logic without the
bookkeeping logic. To prepare for new pointer in dispatch_private_info_t, a
new flags variable is created which stores the ordered and nomerge flags instead
of them being in two separate variables. This will keep the
dispatch_private_info_t structure the same size.
Differential Revision: https://reviews.llvm.org/D47961
llvm-svn: 336568
These are preliminary changes that attempt to use C++11 Atomics in the runtime.
We are expecting better portability with this change across architectures/OSes.
Here is the summary of the changes.
Most variables that need synchronization operation were converted to generic
atomic variables (std::atomic<T>). Variables that are updated with combined CAS
are packed into a single atomic variable, and partial read/write is done
through unpacking/packing
Patch by Hansang Bae
Differential Revision: https://reviews.llvm.org/D47903
llvm-svn: 336563
The current implementation always provides the thread-num for the current
parallel region. This patch fixes the behavior for ancestor levels >0.
Differential Revision: https://reviews.llvm.org/D46533
llvm-svn: 336085
Introduce OPENMP_INSTALL_LIBDIR and use in all install() commands.
This also fixes installation of libomptarget-nvptx that previously
didn't honor {OPENMP,LLVM}_LIBDIR_SUFFIX.
Differential Revision: https://reviews.llvm.org/D47130
llvm-svn: 333284
implicit_task_end callbacks in nested parallel regions did not always give the
correct thread_num, since the inner parallel region may have already been
finalized.
Now, the thread_num is stored at the beginning of the implicit task and
retrieved at the end, whenever necessary.
A testcase was added as well.
Differential Revision: https://reviews.llvm.org/D46260
llvm-svn: 331632
Currently, the affinity API reports garbage for the initial place list and any
thread's place lists when using KMP_AFFINITY=none|compact|scatter.
This patch does two things:
for KMP_AFFINITY=none, Creates a one entry table for the places, this way, the
initial place list is just a single place with all the proc ids in it. We also
set the initial place of any thread to 0 instead of KMP_PLACE_ALL so that the
thread reports that single place (place 0) instead of garbage (-1) when using
the affinity API.
When non-OMP_PROC_BIND affinity is used
(including KMP_AFFINITY=compact|scatter), a thread's place list is populated
correctly. We assume that each thread is assigned to a single place. This is
implemented in two of the affinity API functions
Differential Revision: https://reviews.llvm.org/D45527
llvm-svn: 330283
This patch introduces GOMP_taskloop to our API. It adds GOMP_4.5 to our
version symbols. Being a wrapper around __kmpc_taskloop, the function
creates a task with the loop bounds properly nested in the shareds so that
the GOMP task thunk will work properly. Also, the firstprivate copy constructors
are properly handled using the __kmp_gomp_task_dup() auxiliary function.
Currently, only linear spawning of tasks is supported
for the GOMP_taskloop interface.
Differential Revision: https://reviews.llvm.org/D45327
llvm-svn: 330282
This change removes the unnecessary lock operation on __kmp_initz_lock inside
the __kmp_atfork_child() function for Linux; the lock variable is initialized
in the same function later.
Patch by Hansang Bae
Differential Revision: https://reviews.llvm.org/D44949
llvm-svn: 328900
Added settings code to read OMP_TARGET_OFFLOAD environment variable. Added
target-offload-var ICV as __kmp_target_offload, set via OMP_TARGET_OFFLOAD,
if available, otherwise defaulting to DEFAULT. Valid values for the ICV are
specified as enum values {0,1,2} for disabled, default, and mandatory. An
internal API access function __kmpc_get_target_offload is provided.
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D44577
llvm-svn: 328046
The thread_num parameter of ompt_get_task_info() was not being used previously,
but need to be set.
The print_task_type() function (form the task-types.c testcase) was merged into
the print_ids() function (in callback.h). Testing of ompt_get_task_info() was
added to the task-types.c testcase. It was not tested extensively previously.
Differential Revision: https://reviews.llvm.org/D42472
llvm-svn: 326338
This is required to be NULL for implicit barriers at the end of a
parallel region. Noticed in review of D43191.
Differential Revision: https://reviews.llvm.org/D43308
llvm-svn: 325922
Only use ompt_ functions when testing OMPT in api_calls testcase.
Add size parameter to print_list.
Fix small bug in implementation of ompt_get_partition_place_nums(): return correct length.
Differential Revision: https://reviews.llvm.org/D42162
llvm-svn: 325422
If tool initialization returns 0, OMPT should not be active. The current
implementation provided some callback invocations in this case.
Differential Revision: https://reviews.llvm.org/D42709
llvm-svn: 324320
The defintion is not part of the spec and thus should not have the prefix
"ompt_" but rather a prefix that indicates that this is implementation
specific.
Differential Revision: https://reviews.llvm.org/D41166
llvm-svn: 322621
