This is a partial fix for bug 34050.
This prevents callers of omp_set_lock (which does not hold __kmp_global_lock)
from ever seeing an uninitialized version of __kmp_i_lock_table.table.
It does not solve a use-after-free race condition if omp_set_lock obtains a
pointer to __kmp_i_lock_table.table before it is updated and then attempts to
dereference afterwards. That race is far less likely and can be handled in a
separate patch.
The unit test usually segfaults on the current trunk revision. It passes with
the patch.
Patch by Adam Azarchs
Differential Revision: https://reviews.llvm.org/D39439
llvm-svn: 317115
The code is tested to work with latest clang, GNU and Intel compiler. The implementation
is optimized for low overhead when no tool is attached shifting the cost to execution with
tool attached.
This patch does not implement OMPT for libomptarget.
Patch by Simon Convent and Joachim Protze
Differential Revision: https://reviews.llvm.org/D38185
llvm-svn: 317085
This change fixes the implementation of OMP_THREAD_LIMIT. The implementation of
this previously was not restricted to a contention group (but it should be,
according to the spec), and this is fixed here. A field is added to root thread
to store a counter of the threads in the contention group. An extra check is
added when reserving threads for a parallel region that checks this variable and
compares to threadlimit-var, which is implemented as a new global variable,
kmp_cg_max_nth. Associated settings changes were also made, and clean up of
comments that referred to OMP_THREAD_LIMIT, but should refer to the new
KMP_DEVICE_THREAD_LIMIT (added in an earlier patch).
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D35912
llvm-svn: 309319
Summary:
Taskloop implementation is extended by using recursive task scheduling.
Envirable KMP_TASKLOOP_MIN_TASKS added as a manual threshold for the user
to switch from recursive to linear tasks scheduling.
Details:
* The calculations for the loop parameters are moved from __kmp_taskloop_linear
upper level
* Initial calculation is done in the __kmpc_taskloop, further range splitting
is done in the __kmp_taskloop_recur.
* Added threshold to switch from recursive to linear tasks scheduling;
* One half of split range is scheduled as an internal task which just moves
sub-range parameters to the stealing thread that continues recursive
scheduling (if number of tasks still enough), the other half is processed
recursively;
* Internal task duplication routine fixed to assign parent task, that was not
needed when all tasks were scheduled by same thread, but is needed now.
Patch by Andrey Churbanov
Differential Revision: https://reviews.llvm.org/D35273
llvm-svn: 308338
I've found it very difficult to get test/parallel/omp_nested.c to pass
consistently across my build environments. The problem is that it creates N^2
threads (it is testing nested parallel regions), and that often exceeds the
thread limits on systems with many cores. We do raise the process limits in
lit, and that often helps, but if running lit with a smaller number of threads
or on a system where we're otherwise resource constrained, this particular test
tends to fail (because the runtime cannot create a sufficient number of
threads).
This seems to work: if the maximum number of threads is more than some small
number, then cap the number of threads used for the parallel region. The choice
of 4 here is somewhat arbitrary.
Differential Revision: https://reviews.llvm.org/D32033
llvm-svn: 306357
With these settings, the create_hwloc_map() method was being called causing an
assert(). After some consideration, it was determined that disabling affinity
explicitly should just disable hwloc as well. i.e., KMP_AFFINITY overrides
KMP_TOPOLOGY_METHOD. This lets the user know that the Hwloc mechanism is being
ignored when KMP_AFFINITY=disabled.
Differential Revision: https://reviews.llvm.org/D33208
llvm-svn: 304344
Without this fix cancellation status for parallel, sections and for persists
across construct boundaries.
Differential Revision: https://reviews.llvm.org/D31419
llvm-svn: 299434
When using -rtlib=libgcc, the fallback implementation of __atomic_*
builtins is provided via libatomic (included in GCC). However, neither
GCC itself nor clang link libatomic implicitly, and it seems that GCC
upstream expects projects to link it explicitly as necessary.
Since compiler-rt provides __atomic_* builtins directly in the main
library, check if they are provided by the default libraries first.
If they are not, check if -latomic is available to provide them
and add explicit -latomic for tests in this case.
This fixes unresolved __atomic_load() references when running openmp
tests on i386 with libgcc backend.
Differential Revision: https://reviews.llvm.org/D30083
llvm-svn: 296183
Added test kmp_task_reduction_nest.cpp which has an example of
possible compiler codegen.
Differential Revision: https://reviews.llvm.org/D29600
llvm-svn: 295343
The lock tables were being reallocated if kmp_set_defaults() was called.
In the env_init code it says that the user should be able to switch between
different KMP_CONSISTENCY_CHECK values which is what this change enables.
llvm-svn: 292349
Support finding lit as plain 'lit', which is the name used by setup.py
in LLVM's utils/lit.
Differential Revision: https://reviews.llvm.org/D25072
llvm-svn: 282876
Fix lit search to correctly respect LIBOMP_LLVM_LIT_EXECUTABLE as full
program path.
The variable passed to find_program() is created by CMake as a cache
variable, and therefore can be directly overriden by the user. Since
this was the design of LIBOMP_LLVM_LIT_EXECUTABLE (as can be deduced
from the error messages) and there is no other use of LIT_EXECUTABLE,
remove the redundant variable and pass LIBOMP_LLVM_LIT_EXECUTABLE
directly to find_program().
Furthermore, the previous code did not work since the HINTS argument
specifies more search directories rather than expected full path.
Quoting the CMake documentation:
> 3. Search the paths specified by the HINTS option. These should be
> paths computed by system introspection, such as a hint provided by
> the location of another item already found. Hard-coded guesses should
> be specified with the PATHS option.
Differential Revision: https://reviews.llvm.org/D24710
llvm-svn: 281887
Previous differencials D23305-D23310 changed task frame information management only for the kmp interface, but not for the whole gomp interface. This broke some testcases when building with gcc.
This patch fixes the broken task frame information for the gomp interface.
Patch by Joachim Protze!
Differential Revision: https://reviews.llvm.org/D24502
llvm-svn: 281468
In case, the current team is a serialized team (lwt), the frame information should be written to this data structure.
Before, nested serialized teams would overwrite the same task information.
Patch by Joachim Protze!
Differential Revision: https://reviews.llvm.org/D23310
llvm-svn: 281467
The comment already states, that this function should work similarly as __ompt_get_taskinfo.
The function only looked for lwt entries of the current team, but not when unrolling the parents. This fix aligns the implementation to __ompt_get_taskinfo.
The new test case creates a single theaded team (->lwt) and then a nested active team.
Before the innermost print_id(1) would deliver a different team then the outer print_id(0).
Patch by Joachim Protze!
Differential Revision: https://reviews.llvm.org/D23309
llvm-svn: 281466
The exit address is set when execution of a task is started and should be reset as soon as the execution is finished.
Especially for the asm implementation of __kmp_invoke_microtask, resetting in this call would be painfull, so reset just after the invokation.
The testcase shows the effect of this patch:
Before, the implicit barriers at the end of an implicit task would see an exit address for the implicit task.
This barrier is a task scheduling point. Thus, any explicit task scheduled there would see an exit, but no reenter address for the implicit task.
Patch by Joachim Protze!
Differential Revision: https://reviews.llvm.org/D23307
llvm-svn: 281465
The latest OMPT spec changed the semantic of a tasks reenter frame to be the application frame, that will be entered, when the runtime frame drops.
Before it was the last frame in the runtime. This doesn't work for some gcc execution pathes or even clang generated code for :
Since there is no runtime frame between the executed task and the encountering task.
The test case compares exit and reenter addresses against addresses captured in application code
Patch by Joachim Protze!
Differential Revision: https://reviews.llvm.org/D23305
llvm-svn: 281464
OMPT tests can check for right frame information of tasks:
* parent_task_frame was directly printed as a pointer, but actually points to a struct ompt_frame {void*, void*}
* NULL is printed in the beginning of execution and loaded to FileChecker variable [[NULL]]
* implicit tasks now also print their frame information
* macro to print frame address from application
* print task info for barrier begin
Patch by Joachim Protze!
Differential Revision: https://reviews.llvm.org/D23304
llvm-svn: 281463
Summary:
On FreeBSD, linking the misc_bugs/omp_foreign_thread_team_reuse.c test
case fails with:
/usr/local/bin/ld: /tmp/omp_foreign_thread_team_reuse-c5e71b.o: undefined reference to symbol 'pthread_create@@FBSD_1.0'
This is because the program is linked without `-lpthread`. Since the
%libomp-compile-and-run macro does not allow that option to be added to
the compile command line, split it up and add the required `-lpthread`
between %libomp-compile and %libomp-run.
Reviewers: jlpeyton, hfinkel, Hahnfeld
Subscribers: Hahnfeld, emaste, openmp-commits
Differential Revision: https://reviews.llvm.org/D23084
llvm-svn: 278036
Consider the following code:
int dep;
#pragma omp target nowait depend(out: dep)
{
sleep(1);
}
#pragma omp task depend(in: dep)
{
printf("Task with dependency\n");
}
printf("Doing some work...\n");
In its current state the runtime will block on the second task and not
continue execution.
Differential Revision: https://reviews.llvm.org/D23116
llvm-svn: 277992
Consider the following code which may be executed by a serial team:
int dep;
#pragma omp target nowait depend(out: dep)
{
sleep(1);
}
#pragma omp task depend(in: dep)
{
#pragma omp target nowait
{
sleep(1);
}
}
Here the explicit task may not be freed until the nested proxy task has
finished. The current code hasn't considered this and called __kmp_free_task
anyway which triggered an assert because of remaining incomplete children:
KMP_DEBUG_ASSERT( TCR_4(taskdata->td_incomplete_child_tasks) == 0 );
Differential Revision: https://reviews.llvm.org/D23115
llvm-svn: 277991
These tests are now modeled after the sections nowait test where threads wait
to be released in the first construct (either for or single) and the last thread
skips the last for/single construct and releases those threads. If the test
fails, then it hangs because an unnecessary barrier is executed in between the
constructs.
llvm-svn: 274641
This rewrite of the omp_sections_nowait.c test file causes it to hang if the
nowait is not respected. If the nowait isn't respected, the lone thread which
can escape the first sections construct will just sleep at a barrier which
shouldn't exist. All reliance on timers is taken out. For good measure, the test
makes sure that all eight sections are executed as well. The test should take no
longer than a few seconds on any modern machine.
Differential Revision: http://reviews.llvm.org/D21842
llvm-svn: 274151
* Incorrect lock value written in __kmp_test_futex_lock
* Incorrect lock value check in tas/futex lock with USE_LOCK_PROFILE on
Patch by Hansang Bae
llvm-svn: 274053
Bug fix for hang when omp task and nested parallelism used together.
Still some problem remains with task state saving/restoring, but
user's case works fine now. All tasking unit tests passed as well.
Patch by Andrey Churbanov
Differential Revision: http://reviews.llvm.org/D21558
llvm-svn: 273297
Refactored __kmp_execute_tasks_template to shorten and remove code redundancy.
The original code for __kmp_execute_tasks_template was very redundant with
large sections of repeated code that needed to be kept consistent, and goto
statements that made the control flow difficult to discern. This refactoring
removes all gotos and redundancy.
Patch by Terry Wilmarth
Differential Revision: http://reviews.llvm.org/D20879
llvm-svn: 272286
The problem is the lack of dispatch buffers when thousands of loops with nowait,
about 10 iterations each, are executed by hundreds of threads. We only have
built-in 7 dispatch buffers, but there is a need in dozens or hundreds of
buffers.
The problem can be fixed by setting KMP_MAX_DISP_BUF to bigger value. In order
to give users same possibility I changed build-time control into run-time one,
adding API just in case.
This change adds an environment variable KMP_DISP_NUM_BUFFERS and a new API
function kmp_set_disp_num_buffers(int num_buffers).
The KMP_DISP_NUM_BUFFERS envirable works only before serial initialization,
because during the serial initialization we already allocate buffers for the hot
team, so it is too late to change the number of buffers later (or we need to
reallocate buffers for all teams which sounds too complicated). The
kmp_set_defaults() routine does not work for this envirable, because it calls
serial initialization before reading the parameter string. So a new routine,
kmp_set_disp_num_buffers(), is created so that it can set our internal global
variable before the library initialization. If both the envirable and API used
the envirable wins.
Differential Revision: http://reviews.llvm.org/D20697
llvm-svn: 271318
These changes allow testing on Windows using clang.exe.
There are two main changes:
1. Only link to -lm when it actually exists on the system
2. Create basic versions of pthread_create() and pthread_join() for windows.
They are not POSIX compliant by any stretch but will allow any existing
and future tests to use pthread_create() and pthread_join() for testing
interactions of libomp with os threads.
Differential Revision: http://reviews.llvm.org/D20391
llvm-svn: 270464
This change adds a new entry point,
kmp_aligned_malloc(size_t size, size_t alignment), an entry point corresponding
to kmp_malloc() but with the capability to return aligned memory as well.
Other allocator routines have been adjusted so that kmp_free() can be used for
freeing memory blocks allocated by any kmp_*alloc() routine, including the new
kmp_aligned_malloc() routine.
Differential Revision: http://reviews.llvm.org/D19814
llvm-svn: 269365
After hot teams were enabled by default, the library started using levels kept
in the team structure. The levels are broken in case foreign thread exits and
puts its team into the pool which is then re-used by another foreign thread.
The broken behavior observed is when printing the levels for each new team, one
gets 1, 2, 1, 2, 1, 2, etc. This makes the library believe that every other
team is nested which is incorrect. What is wanted is for the levels to be
1, 1, 1, etc.
Differential Revision: http://reviews.llvm.org/D19980
llvm-svn: 269363
Jonathan Peyton