This is the first of seven patches that implements OMPD, a debugging interface to support debugging of OpenMP programs.
It contains support code required in "openmp/runtime" for OMPD implementation.
Reviewed By: @hbae
Differential Revision: https://reviews.llvm.org/D100181
Refactored code of dependence processing and added new inoutset dependence type.
Compiler can set dependence flag to 0x8 when call __kmpc_omp_task_with_deps.
Size of type of the dependence flag changed from 1 to 4 bytes in clang.
All dependence flags library gets so far and corresponding dependence types:
1 - IN, 2 - OUT, 3 - INOUT, 4 - MUTEXINOUTSET, 8 - INOUTSET.
Differential Revision: https://reviews.llvm.org/D97085
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.
Nesting mode is a new experimental feature in the OpenMP
runtime. It allows a user to set up nesting for an application in a
way that corresponds to the hardware topology levels on the machine an
application is being run on. For example, if a machine has 2 sockets,
each with 12 cores, then use of nesting mode could set up an outer
level of nesting that uses 2 threads per parallel region, and an inner
level of nesting that uses 12 threads per parallel region.
Nesting mode is controlled with the KMP_NESTING_MODE environment
variable as follows:
1) KMP_NESTING_MODE = 0: Nesting mode is off (default); max-active-levels-var
is set to 1 (the default -- nesting is off, nested parallel regions
are serialized).
2) KMP_NESTING_MODE = 1: Nesting mode is on, and a number of threads
will be assigned for each level discovered in the machine topology;
max-active-levels-var is set to the number of levels discovered.
3) KMP_NESTING_MODE = n, n>1: [Note: this option is experimental and may change
or be removed in the future.] Nesting mode is on, and a number of
threads will be assigned for each topology level discovered on the
machine, up to k<=n levels (since there may be fewer than n levels
discovered in the topology), and beyond the kth level, nested parallel
regions will be serialized; NOTE: max-active-levels-var is 1 (the default --
nesting is off, and nested parallel regions are serialized until the
user changes max-active-levels-var.
If the user sets OMP_NUM_THREADS or OMP_MAX_ACTIVE_LEVELS, they will
override KMP_NESTING_MODE settings for the associated environment
variables. The detected topology may be limited by an affinity mask
setting on the initial thread, or if the user sets KMP_HW_SUBSET. See
also: KMP_HOT_TEAMS_MAX_LEVEL for controlling use of hot teams for
nested parallel regions. Note that this feature only sets numbers of
threads used at nesting levels. The user should make use of
OMP_PLACES and OMP_PROC_BIND or KMP_AFFINITY for affinitizing those
threads, if desired.
Differential Revision: https://reviews.llvm.org/D102188
When on KNL and L2 or Tile layer is detected, manually add
the corresponding layer which is equivalent.
Differential Revision: https://reviews.llvm.org/D102865
Warnings on deprecated api cannot be suppressed if the library is not initialized.
With this change it is possible to set KMP_WARNINGS=false to suppress the warnings.
Differential Revision: https://reviews.llvm.org/D102676
Bug 49356 (https://bugs.llvm.org/show_bug.cgi?id=49356) reports crash in
the test case `tasking/bug_taskwait_detach.cpp`, which is caused by the wrong
function declaration. `gtid` in `__kmpc_omp_task` should be `kmp_int32`.
Reviewed By: AndreyChurbanov
Differential Revision: https://reviews.llvm.org/D102584
This is the first in a series of changes to the OpenMP runtime
that have been done internally by Microsoft. This patch makes
the necessary changes to enable libomp.dll to build with
the MSVC compiler targeting ARM64.
Differential Revision: https://reviews.llvm.org/D101173
When KMP_AFFINITY is set, each worker thread's gtid value is used as an
index into the place list to determine the thread's placement. With hidden
helpers enabled, this gtid value is shifted down leading to unexpected
shifted thread placement. This patch restores the previous behavior by
adjusting the mask index to take the number of hidden helper threads
into account.
Hidden helper threads are given the full initial mask and do not
participate in any of the other affinity mechanisms (place partitioning,
balanced affinity). Their affinity is only printed for debug builds.
Differential Revision: https://reviews.llvm.org/D101882
This patch does the following:
1) Introduce kmp_topology_t as the runtime-friendly structure (the
corresponding global variable is __kmp_topology) to determine the
exact machine topology which can vary widely among current and future
architectures. The current design is not easy to expand beyond the assumed
three layer topology: sockets, cores, and threads so a rework capable of
using the existing KMP_AFFINITY mechanisms is required.
This new topology structure has:
* The depth and types of the topology
* Ratio count for each consecutive level (e.g., number of cores per
socket, number of threads per core)
* Absolute count for each level (e.g., 2 sockets, 16 cores, 32 threads)
* Equivalent topology layer map (e.g., Numa domain is equivalent to
socket, L1/L2 cache equivalent to core)
* Whether it is uniform or not
The hardware threads are represented with the kmp_hw_thread_t
structure. This structure contains the ids (e.g., socket 0, core 1,
thread 0) and other information grabbed from the previous Address
structure. The kmp_topology_t structure contains an array of these.
2) Generalize the KMP_HW_SUBSET envirable for the new
kmp_topology_t structure. The algorithm doesn't assume any order with
tiles,numa domains,sockets,cores,threads. Instead it just parses the
envirable, makes sure it is consistent with the detected topology
(including taking into account equivalent layers) and then trims away
the unneeded subset of hardware threads. To enable this, a new
kmp_hw_subset_t structure is introduced which contains a vector of
items (hardware type, number user wants, offset). Any keyword within
__kmp_hw_get_keyword() can be used as a name and can be shortened as
well. e.g.,
KMP_HW_SUBSET=1s,2numa,4tile,2c,3t can be used on the KNL SNC-4 machine.
3) Simplify topology detection functions so they only do the singular
task of detecting the machine's topology. Printing, and all
canonicalizing functionality is now done afterwards. So many lines of
duplicated code are eliminated.
4) Add new ll_caches and numa_domains to OMP_PLACES, and
consequently, KMP_AFFINITY's granularity setting. All the names within
__kmp_hw_get_keyword() are available for use in OMP_PLACES or
KMP_AFFINITY's granularity setting.
5) Simplify and future-proof code where explicit lists of allowed
affinity settings keywords inside if() conditions.
6) Add x86 CPUID leaf 4 cache detection to existing x2apic id method
so equivalent caches could be detected (in particular for the ll_caches
place).
Differential Revision: https://reviews.llvm.org/D100997
Getting my feet wet here as a new committer.
Correct misspelling in check-depends.pl.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D101552
Implement the remaining GOMP_* functions to support task reductions
in taskgroup, parallel, loop, and taskloop constructs. The unused mem
argument to many of the work-sharing constructs has to do with the
scan() directive/ inscan() modifier. If mem is set, each function
will call KMP_FATAL() and tell the user scan/inscan is unsupported. The
GOMP reduction implementation is kept separate from our implementation
because of how GOMP presents reduction data and computes the reductions.
GOMP expects the privatized copies to be present even after a #pragma
omp parallel reduction(task:...) region has ended so the data is stored
inside GOMP's uintptr_t* data pseudo-structure. This style is tightly
coupled with GCC compiler codegen. There also isn't any init(),
combiner(), fini() functions in GOMP's codegen so the two
implementations were to disparate to try to wrap GOMP's around our own.
Differential Revision: https://reviews.llvm.org/D98806
Current atfork() handler for child processes does not reset
the affinity masks array which prevents users from setting their own
affinity in child processes.
Differential Revision: https://reviews.llvm.org/D99218
omp_is_initial_device() is marked as a built-in function in the current
compiler, and user code guarded by this call may be optimized away,
resulting in undesired behavior in some cases. This patch provides a
possible fix for such cases by defining the routine as a variant
function and removing it from builtin list.
Differential Revision: https://reviews.llvm.org/D99447
The second argument to the strnlen_s(str, size) function should be
sizeof(str) when str is a true array of characters with known size
(instead of just a char*). Use type traits to determine if first
parameter is a character array and use the correct size based on that
trait.
Differential Revision: https://reviews.llvm.org/D98209
-- 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
It is reported that after enabling hidden helper thread, the program
can hit the assertion `new_gtid < __kmp_threads_capacity` sometimes. The root
cause is explained as follows. Let's say the default `__kmp_threads_capacity` is
`N`. If hidden helper thread is enabled, `__kmp_threads_capacity` will be offset
to `N+8` by default. If the number of threads we need exceeds `N+8`, e.g. via
`num_threads` clause, we need to expand `__kmp_threads`. In
`__kmp_expand_threads`, the expansion starts from `__kmp_threads_capacity`, and
repeatedly doubling it until the new capacity meets the requirement. Let's
assume the new requirement is `Y`. If `Y` happens to meet the constraint
`(N+8)*2^X=Y` where `X` is the number of iterations, the new capacity is not
enough because we have 8 slots for hidden helper threads.
Here is an example.
```
#include <vector>
int main(int argc, char *argv[]) {
constexpr const size_t N = 1344;
std::vector<int> data(N);
#pragma omp parallel for
for (unsigned i = 0; i < N; ++i) {
data[i] = i;
}
#pragma omp parallel for num_threads(N)
for (unsigned i = 0; i < N; ++i) {
data[i] += i;
}
return 0;
}
```
My CPU is 20C40T, then `__kmp_threads_capacity` is 160. After offset,
`__kmp_threads_capacity` becomes 168. `1344 = (160+8)*2^3`, then the assertions
hit.
Reviewed By: protze.joachim
Differential Revision: https://reviews.llvm.org/D98838
For clang this change is NFC cleanup, because clang
never calls atomic functions from runtime library.
Basically, pause is good in spin-loops waiting for something.
Atomic CAS loops do not wait for anything,
each CAS failure means some other thread progressed.
Performance experiments show that the pause only causes unnecessary slowdown
on CPUs with slow pause instruction, no difference on CPUs with fast pause
instruction, removal of the pause gives lesser binary size which is good.
Differential Revision: https://reviews.llvm.org/D97079
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 is a preview of allocator support for target memory that depends on the
offload runtime API which allocates memory as described below.
llvm_omp_target_alloc_host(size_t size, int device_num);
-- Returns non-migratable memory owned by host.
-- Memory is accessible by host and device(s).
llvm_omp_target_alloc_shared(size_t size, int device_num);
-- Returns migratable memory owned by host and device.
-- Memory is accessible by host and device.
llvm_omp_target_alloc_device(size_t size, int device_num);
-- Returns memory owned by device.
-- Memory is only accessible by device.
New memory space and predefined allocator names are
-- llvm_omp_target_host_mem_space
-- llvm_omp_target_shared_mem_space
-- llvm_omp_target_device_mem_space
-- llvm_omp_target_host_mem_alloc
-- llvm_omp_target_shared_mem_alloc
-- llvm_omp_target_device_mem_alloc
Differential Revision: https://reviews.llvm.org/D96669
Cleanup changes:
- check value read from file;
- remove dead code;
- make unsigned variable to read hexadecimal number to;
- add debug assertion to check ref count.
Differential Revision: https://reviews.llvm.org/D96893
Stitching id could be overridden causing reference of destroyed object
when number of teams is 1. The patch separates stitching id store
location for teams and parallel nested in teams.
Differential Revision: https://reviews.llvm.org/D96562
Allow users to use a non-system version of perl, python and awk, which is useful
in certain package managers.
Reviewed By: JDevlieghere, MaskRay
Differential Revision: https://reviews.llvm.org/D95119
PR#49334 reports a crash when offloading to x86_64 with `target nowait`,
which is caused by referencing a nullptr. The root cause of the issue is, when
pushing a hidden helper task in `__kmp_push_task`, it also maps the gtid to its
shadow gtid, which is wrong.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D97329
When including <ostream>, the register_callback macro of the OMPT callback.h
clashes with a function defined in ostream. This patch renames the macro
and includes ompt into the macro name.
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
Only attempt shutdown if lpReserved is NULL. The Windows documentation
states:
When handling DLL_PROCESS_DETACH, a DLL should free resources such as
heap memory only if the DLL is being unloaded dynamically (the
lpReserved parameter is NULL). If the process is terminating (the
lpReserved parameter is non-NULL), all threads in the process except the
current thread either have exited already or have been explicitly
terminated by a call to the ExitProcess function, which might leave some
process resources such as heaps in an inconsistent state. In this case,
it is not safe for the DLL to clean up the resources. Instead, the DLL
should allow the operating system to reclaim the memory.
Differential Revision: https://reviews.llvm.org/D96750
This patch limits the number of dispatch buffers (used for
loop worksharing construct) to between 1 and 4096.
Differential Revision: https://reviews.llvm.org/D96749
AndreyChurbanov