__kmp_realloc_task_deque implicitly assumes, that the task queue is full
(ntasks == size), therefore tail = size in line 319.
An assertion is added to document this assumption.
The first check for a full queue is before the locking and might not hold
when the lock is taken. So, we need to check again for this condition when
we have the lock.
Reviewed By: AndreyChurbanov
Differential Revision: https://reviews.llvm.org/D80480
Spurious assertion failures are symptoms of a race condition for the handling
of detached tasks:
Assertion failure at kmp_tasking.cpp(3744): taskdata->td_flags.complete == 1.
Assertion failure at kmp_tasking.cpp(710): taskdata->td_flags.executing == 0.
in the case of detach=true, all accesses to taskdata in __kmp_task_finish need
to happen before (~line 873):
taskdata->td_flags.proxy = TASK_PROXY;
This assignment signals to __kmp_fulfill_event, that the task will need to be
freed there. So, conceptionally the ownership of taskdata is moved.
Reviewed By: AndreyChurbanov
Differential Revision: https://reviews.llvm.org/D79702
This patch adds a libomptarget plugin for the NEC SX-Aurora TSUBASA Vector
Engine (VE target). The code is largely based on the existing generic-elf
plugin and uses the NEC VEO and VEOSINFO libraries for offloading.
Differential Revision: https://reviews.llvm.org/D76843
D78566 introduced a `\bnot\b` lit substitution in OpenMP test suites.
However, that would corrupt a command like
`FileCheck -implicit-check-not` or any file name like `%t.not`. We
could use lookbehind/lookahead assertions to avoid such cases, but
this patch switches to `%not` (suggested during the D78566 review) as
a safer option.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D79529
Summary: There is a typo in DeviceRTLTy::getNumOfDevices that the type of its return value is bool. It will lead to a problem of wrong device number returned from omp_get_num_devices.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: yaxunl, guansong, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D79255
The two locals IsNew and Pointer_IsNew were uninitialized at declaration, and then passed by
reference to Device.getOrAllocTgtPtr which in turn did not assign on all
paths within the function. This resulted in occasional runtime failures in one application.
Device::getOrAllocTgtPtr will now initialize IsNew to false on entry to function.
Differential Revision: https://reviews.llvm.org/D78744
Without this patch, target_data_begin continues after an illegal
mapping or an out-of-memory error on the device. With this patch, it
terminates the runtime with an error instead.
The new test exercises only illegal mappings. I didn't think of a
good way to exercise out-of-memory errors from the test suite.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D78170
Without this patch, the openmp project's test suites do not appear to
have support for negative tests. However, D78170 needs to add a test
that an expected runtime failure occurs.
This patch makes `not` visible in all of the openmp project's test
suites. In all but `libomptarget/test`, it should be possible for a
test author to insert `not` before a use of the lit substitution for
running a test program. In `libomptarget/test`, that substitution is
target-specific, and its value is `echo` when the target is not
available. In that case, inserting `not` before a lit substitution
would expect an `echo` fail, so this patch instead defines a separate
lit substitution for expected runtime fails.
Reviewed By: jdoerfert, Hahnfeld
Differential Revision: https://reviews.llvm.org/D78566
On systems with weak memory consistency, this patch fixes an intermittent crash
in the reduction function called by __kmp_hyper_barrier_gather, which suffers
from a race on a child thread's data.
Reviewed-By: AndreyChurbanov
Differential Revision: https://reviews.llvm.org/D77603
Summary: Current implementation mixed everything up so that there is almost no encapsulation. In this patch, all CUDA related operations are put into a new class DeviceRTLTy and only necessary functions are exposed. In addition, all C++ code now conforms with LLVM code standard, keeping those API functions following C style.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: jfb, yaxunl, guansong, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D77951
...onization
Summary: In previous patch, in order to optimize performance, we only synchronize once
for each target region. The syncrhonization is via stream synchronization.
However, in the extreme situation, the performce might be bad. Consider the
following case: There is a task that requires transferring huge amount of data
(call many times of data transferring function). It is scheduled to the first
stream. And then we have 255 very light tasks scheduled to the remaining 255
streams (by default we have 256 streams). They can be finished before we do
synchronization at the end of the first task. Next, we get another very huge
task. It will be scheduled again to the first stream. Now the first task
finishes its kernel launch and call stream synchronization. Right now, the
stream already contains two kernels, and the synchronization will wait until the
two kernels finish instead of just the first one for the first task.
In this patch, we introduce stream pool. After each synchronization, the stream
will be returned back to the pool to make sure that for each synchronization,
only expected operations are waited.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: gregrodgers, yaxunl, lildmh, guansong, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D77412
Summary: According to comments on bi-weekly meeting, this patch put back old APIs and added new `_async` series
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: yaxunl, guansong, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D77822
Summary:
This patch introduces two things for offloading:
1. Asynchronous data transferring: those functions are suffix with `_async`. They have one more argument compared with their synchronous counterparts: `__tgt_async_info*`, which is a new struct that only has one field, `void *Identifier`. This struct is for information exchange between different asynchronous operations. It can be used for stream selection, like in this case, or operation synchronization, which is also used. We may expect more usages in the future.
2. Optimization of stream selection for data mapping. Previous implementation was using asynchronous device memory transfer but synchronizing after each memory transfer. Actually, if we say kernel A needs four memory copy to device and two memory copy back to host, then we can schedule these seven operations (four H2D, two D2H, and one kernel launch) into a same stream and just need synchronization after memory copy from device to host. In this way, we can save a huge overhead compared with synchronization after each operation.
Reviewers: jdoerfert, ye-luo
Reviewed By: jdoerfert
Subscribers: yaxunl, lildmh, guansong, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D77005
Summary:
[libomptarget][nfc] Move non-freestanding headers out of common
Lowers the bar for building deviceRTL.
Drops math.h entirely as it wasn't used and libm is a big dependency.
Reviewers: jdoerfert, ABataev, grokos
Reviewed By: jdoerfert
Subscribers: jvesely, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D77071
Data race occurs when acquiring lock for critical section
triggering assertion failure. Added barrier to ensure
all memory is commited before checking assertion.
Reviewed By: Hahnfeld
Differential Revision: https://reviews.llvm.org/D76780
Summary:
[libomptarget][nfc] Explicitly static function scope shared variables
`__shared__` in CUDA implies static in function scope. See e.g. D.2.1.1
in CUDA_C_Programming_Guide.pdf,
http://developer.download.nvidia.com/compute/DevZone/docs/html/C/doc/
This is surprising for non-cuda developers, see e.g. D73239 where I thought
local variables would be thread local.
Tested by IR diff of libomptarget.bc (no change), running in tree tests,
and binary diff of the nvcc static archives (no significant change).
Reviewers: jdoerfert, ABataev, grokos
Reviewed By: jdoerfert
Subscribers: openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D76713
Summary: Explicitly initialize data members of RTLsTy class upon construction.
Reviewers: grokos
Subscribers: guansong, openmp-commits, caomhin, kkwli0
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D75946
Summary:
[libomptarget] Implement locks for amdgcn
The nvptx implementation deadlocks on amdgcn. atomic_cas with multiple
active lanes can deadlock - if one lane succeeds, all the others are locked
out. The set_lock implementation therefore runs on a single lane.
Also uses a sleep intrinsic instead of the system clock for a probably
minor performance improvement. The unset/test implementations may be revised
later, based on code size / performance or similar concerns.
This implements the lock at a per-wavefront scope. That's not strictly as
specified, since openmp describes locks in terms of threads. I think the
nvptx implementation provides true per-thread locking on volta and the same
per-warp locking on other architectures.
Reviewers: jdoerfert, ABataev, grokos
Reviewed By: jdoerfert
Subscribers: jvesely, mgorny, jfb, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D75546
Summary:
[libomptarget][nfc] Move GetWarp/LaneId functions into per arch code
No code change for nvptx. Amdgcn currently has two implementations of GetLaneId,
this patch keeps the one a colleague considered to be superior for our ISA.
GetWarpId is currently the same function for amdgcn and nvptx, but I think it's
cleaner to keep it grouped with all the others than to keep it in support.cu.
Reviewers: jdoerfert, grokos, ABataev
Reviewed By: jdoerfert
Subscribers: jvesely, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D75587
Summary:
[libomptarget] Implement hip atomic functions in terms of intrinsics
All but atomicInc can be implemented using type generic clang intrinsics.
There is not yet a corresponding intrinsic for atomicInc in clang, only one in
LLVM. This patch leaves atomicInc as an unresolved symbol.
Reviewers: jdoerfert, ABataev, hfinkel, grokos, arsenm
Reviewed By: arsenm
Subscribers: sri, saiislam, wdng, jvesely, mgorny, jfb, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D73076
Summary: fixed the warning from gcc since prios 0-100 are reserved for the internal use.
Reviewers: grokos
Subscribers: kkwli0, caomhin, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D75458
Summary:
Instead of using global variables with unpredicted time of
deinitialization, use dynamically allocated variables with functions
explicitly marked as global constructor/destructor and priority. This
allows to prevent the crash because of the incorrect order of dynamic
libraries deinitialization.
Reviewers: grokos, hfinkel
Subscribers: caomhin, kkwli0, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D74837
From the context, it looks like the test should not be run with `check-all`,
but it does. It turns out option argument resolving to True/False which
could not be passed down as is. There is one such example in
AddLLVM.cmake.
Summary: The 5.0 spec states, "The omp_get_max_threads routine returns an upper bound on the number of threads that could be used to form a new team if a parallel construct without a num_threads clause were encountered after execution returns from this routine." The attached test shows Max Threads: 96, Num Threads: 128 without the proposed change. The number of threads should not exceed the (max) nthreads ICV, hence we should return the higher SPMD thread number even when omp_get_max_threads() is called in a generic kernel. This change does fail the api test, max_threads.c, because now it would return 64 instead of 32.
Reviewers: jdoerfert, ABataev, grokos, JonChesterfield
Reviewed By: jdoerfert
Subscribers: openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D74092
Summary:
[libomptarget][nfc] Change enum values to match those in cuda/rtl
support.h and cuda/rtl.cpp (and downsteam hsa/rtl.cpp) have enums for execution
mode. These are actually independent - the numbers that used within support, or
within the plugin, are never passed across the boundary.
Nevertheless, trying to work out why the values are different between the two
has generated a reasonable amount of confusion. This patch changes support to
match the values in plugin, on the basis that the plugin also has some comments
which I'd have to update if I changed that one instead. Credit to Ron for
working through this in our own fork. See rocm-developer-tools/aomp/issues/7
for that earlier diagnostic write up.
Also happy with generic = 0, spmd = 1 - provided it's the same in both places.
Reviewers: jdoerfert, grokos, ABataev, ronlieb
Reviewed By: grokos
Subscribers: openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D74503
EXCLUDE_FROM_ALL means something else for add_lit_testsuite as it does
for something like add_executable. Distinguish between the two by
renaming the variable and making it an argument to add_lit_testsuite.
Differential revision: https://reviews.llvm.org/D74168
Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=44733 | TEST 'libomp :: ompt/synchronization/reduction/tree_reduce.c' FAILED on 32-bit x86 ]]
For 32-bit we need at least 3 variables to avoid atomic reduction to be
choosen by runtime function `__kmp_determine_reduction_method`.
This patch adds reduction variables to the testcase.
Reviewers: mgorny, Hahnfeld
Differential Revision: https://reviews.llvm.org/D73850
AndreyChurbanov