The `GlobalTy` helper has been extended to make both the Size and Ptr be
optional. Now `getGlobalMetadataFromDevice`/`Image` is able to write the
size of the global to the struct, instead of just verifying it.
After #146345 the device info implementation requires a value for every
query, rather than silently returning an empty string. This broke the
test for `OL_DEVICE_INFO_VENDOR` on CUDA.
Add a value to the CUDA plugin. We can quite safely hard code this one.
Previously, the user was not able to use more than 48 KB of shared
memory on NVIDIA GPUs. In order to do so, setting the function attribute
`CU_FUNC_ATTRIBUTE_MAX_THREADS_PER_BLOCK` is required, which was not
present in the code base. With this commit, we add the ability toset
this attribute, allowing the user to utilize the full power of their
GPU.
In order to not have to reset the function attribute for each launch of
the same kernel, we keep track of the maximum memory limit (as the
variable `MaxDynCGroupMemLimit`) and only set the attribute if our
desired amount exceeds the limit. By default, this limit is set to 48
KB.
Feedback is greatly appreciated, especially around setting the new
variable as mutable. I did this becuase the `launchImpl` method is const
and I am not able to modify my variable otherwise.
---------
Co-authored-by: Giorgi Gvalia <ggvalia@login33.chn.perlmutter.nersc.gov>
Co-authored-by: Giorgi Gvalia <ggvalia@login07.chn.perlmutter.nersc.gov>
AMD treats this value as a string, so for consistency require this in
NVIDIA as well. This shouldn't change the output of the
`llvm-offload-device-info` tool, but does fix an issue in liboffload
when it tries to query the version.
This allows removal of a specific Image from a Device, rather than
requiring all image data to outlive the device they were created for.
This is required for `ol_program_handle_t`s, which now specify the
lifetime of the buffer used to create the program.
Previously, device info was returned as a queue with each element having
a "Level" field indicating its nesting level. This replaces this queue
with a more traditional tree-like structure.
This should not result in a change to the output of
`llvm-offload-device-info`.
[Offload] Use new error code handling mechanism
This removes the old ErrorCode-less error method and requires
every user to provide a concrete error code. All calls have been
updated.
In addition, for consistency with error messages elsewhere in LLVM, all
messages have been made to start lower case.
Summary:
Handling the RPC server requires running through list of jobs that the
device has requested to be done. Currently this is handled by the thread
that does the waiting for the kernel to finish. However, this is not
sound on NVIDIA architectures and only works for async launches in the
OpenMP model that uses helper threads.
However, we also don't want to have this thread doing work
unnnecessarily. For this reason we track the execution of kernels and
cause the thread to sleep via a condition variable (usually backed by
some kind of futex or other intelligent sleeping mechanism) so that the
thread will be idle while no kernels are running.
Summary:
This patch adds an RPC interface that lives directly in the OpenMP
device runtime. This allows OpenMP to implement custom opcodes.
Currently this is only providing the host call interface, which is the
raw version of reverse offloading. Previously this lived in `libc/` as
an extension which is not the correct place.
The interface here uses a weak symbol for the RPC client by the same
name that the `libc` interface uses. This means that it will defer to
the libc one if both are present so we don't need to set up multiple
instances.
The presense of this symbol is what controls whether or not we set up
the RPC server. Because this is an external symbol it normally won't be
optimized out, so there's a special pass in OpenMPOpt that deletes this
symbol if it is unused during linking. That means at `O0` the RPC server
will always be present now, but will be removed trivially if it's not
used at O1 and higher.
We had three `utils::` namespaces, all with different "meaning" (host,
device, hsa_utils). We should, when we can, keep "include/Shared"
accessible from host and device, thus RefCountTy has been moved to a
separate header. `hsa_utils` was introduced to make `utils::` less
overloaded. And common functionality was de-duplicated, e.g.,
`utils::advance` and `utils::advanceVoidPtr` -> `utils:advancePtr`. Type
punning now checks for the size of the result to make sure it matches
the source type.
No functional change was intended.
We already used a flat array of kernel launch parameters for the AMD GPU
launch but now we also use this scheme for the NVIDIA GPU launch. The
only remaining/required use of the indirection is the host plugin (due
ot ffi). This allows to us simplify the use for non-OpenMP kernel
launch.
Summary:
Currently, we register images into a linear table according to the
logical OpenMP device identifier. We then initialize all of these images
as one block. This logic requires that images are compatible with *all*
devices instead of just the one that it can run on. This prevents us
from running on systems with heterogeneous devices (i.e. image 1 runs on
device 0 image 0 runs on device 1).
This patch reworks the logic by instead making the compatibility check a
per-device query. We then scan every device to see if it's compatible
and do it as they come.
Summary:
Certain plugins can only be built on specific platforms. Previously this
didn't cause issues becaues each one was handled independently. However,
now that we link these all directly they need to be in a CMake list.
Furthermore we use this list to generate a config file. For this reason
these checks are moved to where we normalize the support.
Fixes: https://github.com/llvm/llvm-project/issues/93183
Summary:
We previously had multiple options for this, this patch replaces them
with `LIBOMPTARGET_DLOPEN_PLUGINS=` to be a list of plugins to
dynamically use. It defaults to everything right now. This ignores the
`host` plugin because the `libffi` dependency is going to be removed
soon hopefully in https://github.com/llvm/llvm-project/pull/91264.
Summary:
CUDA does its versioning by putting a redirection in the header so the
API functions remain the same while the symbol changes. These weren't
being used for some functions that required it in the dynamic cuda
version.
These functions have newer verisons that should be used. These are
fairly old as far as I'm aware so we should be able to sweep backward
compatibility under the rug.
Since #87009, libomptarget directly links all the plugins statically.
All the dependencies of plugins got exposed to libomptarget. The CUDA
plugin depends on libcuda and the amdgpu plugin depends on libhsa if not
forced using dlopen. On a cluster with different compute node
architectures, libomptarget can be built and run on different nodes. In
the build stage, if cmake founds libcuda and
`LIBOMPTARGET_FORCE_DLOPEN_LIBCUDA=OFF`, libomptarget links libcuda.so
directly and the result libomptarget may not run a node without a NVIDIA
driver for example a CPU or AMD GPU only machine with a complaint that
libcuda.so not found.
The solution is setting `LIBOMPTARGET_FORCE_DLOPEN_LIBCUDA` and
`LIBOMPTARGET_FORCE_DLOPEN_LIBHSA` `ON`. Preferably this should be
default to maximize the usability of libomptarget. If cmake detects
NVIDIA or AMD software on an OS imaging building node, the resulted
libomptarget may not be able to function on the user side due to the
requirement the existence of vendor runtime libraries.
Summary:
This isn't `libomptarget` anymore, and these messages were always
unnecessary because no other project uses these prefixed messages. The
effect of this is that no longer will the logs have `LIBOMPTARGET --` in
front of everything. We have a message stating when we start building
the offload project so it'll still be trivial to find.
Summary:
No other project has these in the CMake itself, and they're wildly
inconsistent even within the project. These don't really add anything so
I think they should be removed.
Summary:
Since the move to the statically linked plugins, we added a new way to
directly control which plugins will be added. Delete these old ones as
they will cause the build to fail and suggest the new format.
This patch overhauls the `libomptarget` and plugin interface. Currently,
we define a C API and compile each plugin as a separate shared library.
Then, `libomptarget` loads these API functions and forwards its internal
calls to them. This was originally designed to allow multiple
implementations of a library to be live. However, since then no one has
used this functionality and it prevents us from using much nicer
interfaces. If the old behavior is desired it should instead be
implemented as a separate plugin.
This patch replaces the `PluginAdaptorTy` interface with the
`GenericPluginTy` that is used by the plugins. Each plugin exports a
`createPlugin_<name>` function that is used to get the specific
implementation. This code is now shared with `libomptarget`.
There are some notable improvements to this.
1. Massively improved lifetimes of life runtime objects
2. The plugins can use a C++ interface
3. Global state does not need to be duplicated for each plugin +
libomptarget
4. Easier to use and add features and improve error handling
5. Less function call overhead / Improved LTO performance.
Additional changes in this plugin are related to contending with the
fact that state is now shared. Initialization and deinitialization is
now handled correctly and in phase with the underlying runtime, allowing
us to actually know when something is getting deallocated.
Depends on https://github.com/llvm/llvm-project/pull/86971https://github.com/llvm/llvm-project/pull/86875https://github.com/llvm/llvm-project/pull/86868
This patch overhauls the `libomptarget` and plugin interface. Currently,
we define a C API and compile each plugin as a separate shared library.
Then, `libomptarget` loads these API functions and forwards its internal
calls to them. This was originally designed to allow multiple
implementations of a library to be live. However, since then no one has
used this functionality and it prevents us from using much nicer
interfaces. If the old behavior is desired it should instead be
implemented as a separate plugin.
This patch replaces the `PluginAdaptorTy` interface with the
`GenericPluginTy` that is used by the plugins. Each plugin exports a
`createPlugin_<name>` function that is used to get the specific
implementation. This code is now shared with `libomptarget`.
There are some notable improvements to this.
1. Massively improved lifetimes of life runtime objects
2. The plugins can use a C++ interface
3. Global state does not need to be duplicated for each plugin +
libomptarget
4. Easier to use and add features and improve error handling
5. Less function call overhead / Improved LTO performance.
Additional changes in this plugin are related to contending with the
fact that state is now shared. Initialization and deinitialization is
now handled correctly and in phase with the underlying runtime, allowing
us to actually know when something is getting deallocated.
Depends on https://github.com/llvm/llvm-project/pull/86971https://github.com/llvm/llvm-project/pull/86875https://github.com/llvm/llvm-project/pull/86868
In a nutshell, this moves our libomptarget code to populate the offload
subproject.
With this commit, users need to enable the new LLVM/Offload subproject
as a runtime in their cmake configuration.
No further changes are expected for downstream code.
Tests and other components still depend on OpenMP and have also not been
renamed. The results below are for a build in which OpenMP and Offload
are enabled runtimes. In addition to the pure `git mv`, we needed to
adjust some CMake files. Nothing is intended to change semantics.
```
ninja check-offload
```
Works with the X86 and AMDGPU offload tests
```
ninja check-openmp
```
Still works but doesn't build offload tests anymore.
```
ls install/lib
```
Shows all expected libraries, incl.
- `libomptarget.devicertl.a`
- `libomptarget-nvptx-sm_90.bc`
- `libomptarget.rtl.amdgpu.so` -> `libomptarget.rtl.amdgpu.so.18git`
- `libomptarget.so` -> `libomptarget.so.18git`
Fixes: https://github.com/llvm/llvm-project/issues/75124
---------
Co-authored-by: Saiyedul Islam <Saiyedul.Islam@amd.com>
