This PR adds extends liboffload olMemRegister API to handle a case when
a memory block may have been mapped before calling olMemRegister to
support some use cases in libomptarget
Summary:
This PR adds a pointer argument to the initialization routine to be used
for global options. Right now this is used to allow the user to
constrain which backends they wish to use.
If a null argument is passed, the same behavior as before is observed.
This is epxected to be extensible by forcing the user to encode the size
of the struct. So, old executables will encode which fields they have
access to.
We use a macro helper to get this struct rather than a runtime call so
that the current state of the size is baked into the executable rather
than something looked up by the runtime. Otherwise it would just return
the size that the (potentially newer) runtime would see
Summary:
We provide an RPC server to manage calls initiated by the device to run
on the host. This is very useful for the built-in handling we have,
however there are cases where we would want to extend this
functionality.
Cases like Fortran or MPI would be useful, but we cannot put references
to these in the core offloading runtime. This way, we can provide this
as a library interface that registers custom handlers for whatever code
people want.
Add liboffload asynchronous queue query API for libomptarget migration
This PR adds liboffload asynchronous queue query API that needed to make
libomptarget to use liboffload
Add liboffload memory data locking API for libomptarget migration
This PR adds liboffload memory data locking API that needed to make
libomptarget to use liboffload
The code to recognize the level_zero plugin as a liboffload backend was
split from #158900. This PR adds the support back.
---------
Co-authored-by: Alexey Sachkov <alexey.sachkov@intel.com>
Co-authored-by: Nick Sarnie <nick.sarnie@intel.com>
Co-authored-by: Joseph Huber <huberjn@outlook.com>
Introduced in OpenMP 6.0, the device UID shall be a unique identifier of
a device on a given system. (Not necessarily a UUID.) Since it is not
guaranteed that the (U)UIDs defined by the device vendor libraries, such
as HSA, do not overlap with those of other vendors, the device UIDs in
offload are always combined with the offload plugin name. In case the
vendor library does not specify any device UID for a given device, we
fall back to the offload-internal device ID.
The device UID can be retrieved using the `llvm-offload-device-info`
tool.
Summary:
The Offloading library wraps around the underlying plugins. The problem
is that we currently initialize all plugins we find, even if they are
not needed for the program. This is very expensive for trivial uses, as
fully heterogenous usage is quite rare. In practice this means that you
will always pay a 200 ms penalty for having CUDA installed.
This patch changes the behavior to provide accessors into the plugins
and devices that allows them to be initialized lazily. We use a
once_flag, this should properly take a fast-path check while still
blocking on concurrent use.
Making full use of this will require a way to filter platforms more
specifically. I'm thinking of what this would look like as an API.
I'm thinking that we either have an extra iterate function that takes a
callback on the platform, or we just provide a helper to find all the
devices that can run a given image. Maybe both?
Fixes: https://github.com/llvm/llvm-project/issues/159636
If olMemAlloc happens to allocate memory that was already allocated
elsewhere (possibly by another device on another platform), it is now
thrown away and a new allocation generated.
A new `AllocBases` vector is now available, which is an ordered list
of allocation start addresses.
Summary:
This exposes the 'isDeviceCompatible' routine for checking if a binary
*can* be loaded. This is useful if people don't want to consume errors
everywhere when figuring out which image to put to what device.
I don't know if this is a good name, I was thining like `olIsCompatible`
or whatever. Let me know what you think.
Long term I'd like to be able to do something similar to what OpenMP
does where we can conditionally only initialize devices if we need them.
That's going to be support needed if we want this to be more
generic.
The order entries in the tablegen API files are iterated is not the
order
they appear in the file. To avoid any issues with the order changing
in future, we now generate all definitions of a certain class before
class that can use them.
This is a NFC; the definitions don't actually change, just the order
they exist in in the OffloadAPI.h header.
This is equivalent to `cuOccupancyMaxPotentialBlockSize`. It is
currently
only implemented on Cuda; AMDGPU and Host return unsupported.
---------
Co-authored-by: Callum Fare <callum@codeplay.com>
Add the following properties in Offload device info:
* VENDOR_ID
* NUM_COMPUTE_UNITS
* [SINGLE|DOUBLE|HALF]_FP_CONFIG
* NATIVE_VECTOR_WIDTH_[CHAR|SHORT|INT|LONG|FLOAT|DOUBLE|HALF]
* MAX_CLOCK_FREQUENCY
* MEMORY_CLOCK_RATE
* ADDRESS_BITS
* MAX_MEM_ALLOC_SIZE
* GLOBAL_MEM_SIZE
Add a bitfield option to enumerators, allowing the values to be
bit-shifted instead of incremented. Generate the per-type enums using
`foreach` to reduce code duplication.
Use macros in unit test definitions to reduce code duplication.
`MAX_WORK_GROUP_SIZE` now represents the maximum total number of work
groups the device can allocate, rather than the maximum per dimension.
`MAX_WORK_GROUP_SIZE_PER_DIMENSION` has been added, which has the old
behaviour.
Rather than having every "enqueue"-type function have an output pointer
specifically for an output event, just provide an `olCreateEvent`
entrypoint which pushes an event to the queue.
For example, replace:
```cpp
olMemcpy(Queue, ..., EventOut);
```
with
```cpp
olMemcpy(Queue, ...);
olCreateEvent(Queue, EventOut);
```
`olGetKernel` has been replaced by `olGetSymbol` which accepts a
`Kind` parameter. As well as loading information about kernels, it
can now also load information about global variables.
In the future, we want `ol_symbol_handle_t` to represent both kernels
and global variables The first step in this process is a rename and
promotion to a "typed handle".
* Add spec generation to offload-tblgen tool
* This patch adds generation of Sphinx compatible reStructuedText
utilizing the C domain to document the Offload API directly from the
spec definition `.td` files.
* Add Sphinx HTML documentation target
* Introduces the `docs-offload-html` target when CMake is configured
with `LLVM_ENABLE_SPHINX=ON` and `SPHINX_OUTPUT_HTML=ON`. Utilized
`offload-tblgen -gen-spen` to generate Offload API specification docs.
Add info queries for queues and events.
`olGetQueueInfo` only supports getting the associated device. We were
already tracking this so we can implement this for free. We will likely
add other queries to it in the future (whether the queue is empty, what
flags it was created with, etc)
`olGetEventInfo` only supports getting the associated queue. This is
another thing we were already storing in the handle. We'll be able to
add other queries in future (the event type, status, etc)
This is a generated file which contains a macro for all Device Info
keys. This is visible to the plugin interface so that it can use the
definitions in a future patch.
- Update the main README to reflect the current project status
- Rework the main API generation documentation. General fixes/tidying,
but also spell out explicitly how to make API changes at the top of the
document since this is what most people will care about.
---------
Co-authored-by: Martin Grant <martingrant@outlook.com>
`olShutDown` was not properly calling deinit on the platforms, resulting
in random segfaults on AMD devices.
As part of this, `olInit` and `olShutDown` now alloc and free the
offload context rather than it being static. This
allows `olShutDown` to be called within a destructor of a static object
(like the tests do) without having to worry about destructor ordering.
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, if a binary failed to load due to failures when jit
compiling, the function would return success with nullptr. Now it
returns a new plugin error, `COMPILE_FAILURE`.
This is a three element x, y, z size_t vector that can be used any place
where a 3D vector is required. This ensures that all vectors across
liboffload are the same and don't require any resizing/reordering
dances.
Thanks to @RossBrunton for spotting this.
We attempt to clang-format the generated Offload header files, but if
clang-format isn't available we just copy the generated files instead.
That fallback path was missing the correct dependencies.
Fixes#142756
Previously we decided to check in files that we generate with tablegen.
The justification at the time was that it helped reviewers unfamiliar
with `offload-tblgen` see the actual changes to the headers in PRs.
After trying it for a while, it's ended up causing some headaches and is
also not how tablegen is used elsewhere in LLVM.
This changes our use of tablegen to be more conventional. Where
possible, files are still clang-formatted, but this is no longer a hard
requirement. Because `OffloadErrcodes.inc` is shared with libomptarget
it now gets generated in a more appropriate place.
Summary:
We use this sepcial type to indicate a host value, this will be refined
later but for now it's used as a stand-in device for transfers and
queues. It needs a special kind because it is not a device target as the
other ones so we need to differentiate it between a CPU and GPU type.
Fixes: https://github.com/llvm/llvm-project/issues/141436
