This commit adds skewed distribution of iterations in
nonmonotonic:dynamic schedule (static steal) for hybrid systems when
thread affinity is assigned. Currently, it distributes the iterations at
60:40 ratio. Consider this loop with dynamic schedule type,
for (int i = 0; i < 100; ++i). In a hybrid system with 20 hardware
threads (16 CORE and 4 ATOM core), 88 iterations will be assigned to
performance cores and 12 iterations will be assigned to efficient cores.
Each thread with CORE core will process 5 iterations + extras and with
ATOM core will process 3 iterations.
Differential Revision: https://reviews.llvm.org/D152955
This patch fixes assertion failure in dynamic schedule with 8 byte induction
variable. It uses acquire load instead of relaxed to ensure that steal_lock
pointer is not NULL.
Differential Revision: https://reviews.llvm.org/D139373
This fixes warnings like these:
../runtime/src/kmp_dispatch.cpp:2159:24: warning: left operand of comma operator has no effect [-Wunused-value]
OMPT_LOOP_DISPATCH(*p_lb, *p_ub, pr->u.p.st, status);
^~~~~
../runtime/src/kmp_dispatch.cpp:2159:31: warning: left operand of comma operator has no effect [-Wunused-value]
OMPT_LOOP_DISPATCH(*p_lb, *p_ub, pr->u.p.st, status);
^~~~~
../runtime/src/kmp_dispatch.cpp:2159:46: warning: left operand of comma operator has no effect [-Wunused-value]
OMPT_LOOP_DISPATCH(*p_lb, *p_ub, pr->u.p.st, status);
~~~~~~~ ^~
../runtime/src/kmp_dispatch.cpp:2159:50: warning: expression result unused [-Wunused-value]
OMPT_LOOP_DISPATCH(*p_lb, *p_ub, pr->u.p.st, status);
^~~~~~
This check-in adds 4 APIs to support MSVC, specifically:
* 3 APIs (__kmpc_sections_init, __kmpc_next_section,
__kmpc_end_sections) to support the dynamic scheduling of OMP sections.
* 1 API (__kmpc_copyprivate_light, a light-weight version of
__kmpc_copyrprivate) to support the OMP single copyprivate clause.
Differential Revision: https://reviews.llvm.org/D128403
This change adds support for ompt_callback_dispatch with the new
dispatch chunk type introduced in 5.2. Definitions of the new
ompt_work_loop types were also added in the header file.
Differential Revision: https://reviews.llvm.org/D122107
Add use of TPAUSE (from WAITPKG) to the runtime for Intel hardware,
with an envirable to turn it on in a particular C-state. Always uses
TPAUSE if it is selected and enabled by Intel hardware and presence of
WAITPKG, and if not, falls back to old way of checking
__kmp_use_yield, etc.
Differential Revision: https://reviews.llvm.org/D115758
This patch changes the default monotonicity of dynamic schedule from
monotonic to non-monotonic when no modifier is specified.
Differential Revision: https://reviews.llvm.org/D109026
* Add comment to help ensure new construct data are added in two places
* Check for division by zero in the loop worksharing code
* Check for syntax errors in parrange parsing
Differential Revision: https://reviews.llvm.org/D105929
Normalized bounds of chunk of iterations to steal from are inclusive,
so upper bound should not be decremented in expression to check.
Problem was in attempt to steal iterations 0:0, that caused assertion after
wrong decrement. Reported in comment to https://reviews.llvm.org/D103648.
Differential Revision: https://reviews.llvm.org/D104880
Restructured dynamic loop dispatcher code.
Fixed use of dispatch buffers for nonmonotonic dynamic (static_steal) schedule:
- eliminated possibility of stealing iterations of the wrong loop when victim
thread changed its buffer to work on another loop;
- fixed race when victim thread changed its buffer to work in nested parallel;
- eliminated "static" property of the schedule, that is now a single thread can
execute whole loop.
Differential Revision: https://reviews.llvm.org/D103648
The ident_t * argument in __kmp_get_monotonicity was being used without
a customary NULL check, causing the function to crash in a Debug build.
Release builds were not affected thanks to dead store elimination.
-- Added or moved checks to appropriate places.
-- Removed ineffective null check where the pointer is already being
dereferenced around the code.
-- Initialized variables that can be used without definitions.
-- Added call to dlclose/FreeLibrary in OMPT tool activation.
-- Added a new build compiler definition.
Differential Revision: https://reviews.llvm.org/D98584
Restrict the chunk_size * chunk_num to only occur for valid
chunk_nums and reimplement calculating the limit to avoid overflow.
Differential Revision: https://reviews.llvm.org/D96747
and __kmpc_end_masked. The "master" construct is deprecated. Changed
proc-bind keyword from "master" to "primary". Use of both master
construct and master as proc-bind keyword is still allowed, but
deprecated.
Remove references to "master" in comments and strings, and replace
with "primary" or "primary thread". Function names and variables were
not touched, nor were references to deprecated master construct. These
can be updated over time. No new code should refer to master.
This code alleviates some pathological loop parameters (lower,
upper, stride) within calculations involved in the static loop code. It
bounds the chunk size to the trip count if it is greater than the trip
count and also minimizes problematic code for when trip count < nth.
Differential Revision: https://reviews.llvm.org/D96426
This patch introduces a new environment variable to force monotonic
behavior for users that absolutely need it. This is in anticipation
of 5.0 change that uses non-monotonic behavior for dynamic scheduling
by default. Fixes for that and the actual switch are coming soon.
Differential Revision: https://reviews.llvm.org/D95263
This patch partially prepares the runtime source code to be built with
-Wconversion, which should trigger warnings if any implicit conversions
can possibly change a value. For builds done with icc or gcc, all such
warnings are handled in this patch. clang gives a much longer list of
warnings, particularly for sign conversions, which the other compilers
don't report. The -Wconversion flag is commented into cmake files, but
I'm not going to turn it on. If someone thinks it is important, and wants
to fix all the clang warnings, they are welcome to.
Types of changes made here involve either improving the consistency of types
used so that no conversion is needed, or else performing careful explicit
conversions, when we're sure a problem won't arise.
Patch is a combination of changes by Terry Wilmarth and Johnny Peyton.
Differential Revision: https://reviews.llvm.org/D92942
This patch adds the mask and ident_t function to get the
openmp version. It also adds logic to force monotonic:dynamic
behavior when OpenMP version less than 5.0.
The OpenMP version is stored in the format:
major*10+minor e.g., OpenMP 5.0 = 50
Differential Revision: https://reviews.llvm.org/D90632
Add check of negative gtid before indexing __kmp_threads.
This makes static analyzers happier.
This is the first part of the patch split in two parts.
Differential Revision: https://reviews.llvm.org/D84062
Remove all older OMP spec versioning from the runtime and build system.
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D64534
llvm-svn: 365963
This patch adds:
* New omp_sched_monotonic flag to omp_sched_t which is handled within the runtime
* Parsing of monotonic/nonmonotonic in OMP_SCHEDULE
* Tests for the monotonic flag and envirable parsing
* Logic to force monotonic when hierarchical scheduling is used
Differential Revision: https://reviews.llvm.org/D60979
llvm-svn: 359601
The distribute clause needs an explicit push of a timer. The teams
clause needs a timer added and also, similarly to parallel, exchanged
with the serial timer when encountered so that serial regions are
counted properly.
Differential Revision: https://reviews.llvm.org/D59801
llvm-svn: 357621
This patch cleans up the yielding code and makes it optional. An
environment variable, KMP_USE_YIELD, was added. Yielding is still
on by default (KMP_USE_YIELD=1), but can be turned off completely
(KMP_USE_YIELD=0), or turned on only when oversubscription is detected
(KMP_USE_YIELD=2). Note that oversubscription cannot always be detected
by the runtime (for example, when the runtime is initialized and the
process forks, oversubscription cannot be detected currently over
multiple instances of the runtime).
Because yielding can be controlled by user now, the library mode
settings (from KMP_LIBRARY) for throughput and turnaround have been
adjusted by altering blocktime, unless that was also explicitly set.
In the original code, there were a number of places where a double yield
might have been done under oversubscription. This version checks
oversubscription and if that's not going to yield, then it does
the spin check.
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D58148
llvm-svn: 355120
The three switch fallthrough generate a warning with -Wimplicit-fallthrough.
Two are documented as fallthrough, one is not, but I think the intention is to also fallthrough in kmp_tasking.cpp.
Not sure whether kmp.h is the best place to define the macro.
Reviewers: jlpeyton, AndreyChurbanov, Hahnfeld
Reviewed By: jlpeyton
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D56397
llvm-svn: 353052
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
Add omp_pause_resource and omp_pause_resource_all API and enum, plus stub for
internal implementation. Implemented callable helper function to do local pause,
and added basic functionality for hard and soft pause.
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D55078
llvm-svn: 351372
This change includes miscellaneous improvements as follows:
1) Added ompt_get_proc_id() implementation for Windows
2) Added parser and print tool for omp-tool-var, just in case it needs
to be printed (OMP_DISPLAY_ENV)
3) omp_control_tool is exported on Windows
Patch by Hansang Bae
Differential Revision: https://reviews.llvm.org/D50538
llvm-svn: 343137
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
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
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
Allocated memory is typically not 'const' if it needs to be freed.
This patch removes around 50 wrong const attributes, modifies the
corresponding functions and finally gets rid of some const_casts.
These have especially been strange for __kmp_str_fname_free() that
added a 'const' to call __kmp_str_free() which removed it again.
Two minor cleanups that I performed in this process:
* __kmp_tool_libraries now lives in kmp_settings.cpp as it is
used nowhere else.
* __kmp_msg_empty was removed as it was never used and Clang
now complained that it was assigned a string literal that
is 'const char *'.
Differential Revision: https://reviews.llvm.org/D39755
llvm-svn: 317797
The TR6 document is expected to be publically released around November 15.
This patch does not implement OMPT for libomptarget.
Patch by Simon Convent and Joachim Protze
Differential Revision: https://reviews.llvm.org/D39182
llvm-svn: 317339
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
Removes semicolons after if {} blocks, function definitions, etc.
I was able to apply the large OMPT patch cleanly on top of this one
with no conflicts.
llvm-svn: 314340
Minor code cleanup of Klocwork issues. Fatal messages are given no return
attribute. Define and use KMP_NORETURN to work for multiple C++ versions.
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D37275
llvm-svn: 312538
Changes are: got all atomics to accept volatile pointers that allowed
to simplify many type conversions. Windows specific code fixed correspondingly.
Differential Revision: https://reviews.llvm.org/D35417
llvm-svn: 308164
While importing libomp into the FreeBSD base system we encountered
Clang warnings that "'register' storage class specifier is deprecated
and incompatible with C++1z [-Wdeprecated-register]".
Differential Revision: https://reviews.llvm.org/D35124
llvm-svn: 307441
