Re: [Patch][v5] libgomp/nvptx: Prepare for reverse-offload callback handling

[Jakub Jelinek <jakub@redhat.com>]

On Wed, Oct 12, 2022 at 10:55:26AM +0200, Tobias Burnus wrote:
> libgomp/nvptx: Prepare for reverse-offload callback handling
> 
> This patch adds a stub 'gomp_target_rev' in the host's target.c, which will
> later handle the reverse offload.
> For nvptx, it adds support for forwarding the offload gomp_target_ext call
> to the host by setting values in a struct on the device and querying it on
> the host - invoking gomp_target_rev on the result.
> 
> include/ChangeLog:
> 
> 	* cuda/cuda.h (enum CUdevice_attribute): Add
> 	CU_DEVICE_ATTRIBUTE_UNIFIED_ADDRESSING.
> 	(CU_MEMHOSTALLOC_DEVICEMAP): Define.
> 	(cuMemHostAlloc): Add prototype.
> 
> libgomp/ChangeLog:
> 
> 	* config/nvptx/icv-device.c (GOMP_DEVICE_NUM_VAR): Remove
> 	'static' for this variable.
> 	* config/nvptx/libgomp-nvptx.h: New file.
> 	* config/nvptx/target.c: Include it.
> 	(GOMP_ADDITIONAL_ICVS): Declare extern var.
> 	(GOMP_REV_OFFLOAD_VAR): Declare var.
> 	(GOMP_target_ext): Handle reverse offload.
> 	* libgomp-plugin.h (GOMP_PLUGIN_target_rev): New prototype.
> 	* libgomp-plugin.c (GOMP_PLUGIN_target_rev): New, call ...
> 	* target.c (gomp_target_rev): ... this new stub function.
> 	* libgomp.h (gomp_target_rev): Declare.
> 	* libgomp.map (GOMP_PLUGIN_1.4): New; add GOMP_PLUGIN_target_rev.
> 	* plugin/cuda-lib.def (cuMemHostAlloc): Add.
> 	* plugin/plugin-nvptx.c: Include libgomp-nvptx.h.
> 	(struct ptx_device): Add rev_data member. 
> 	(nvptx_open_device): Remove async_engines query, last used in
> 	r10-304-g1f4c5b9b; add unified-address assert check.
> 	(GOMP_OFFLOAD_get_num_devices): Claim unified address
> 	support.
> 	(GOMP_OFFLOAD_load_image): Free rev_fn_table if no
> 	offload functions exist. Make offload var available
> 	on host and device.
> 	(rev_off_dev_to_host_cpy, rev_off_host_to_dev_cpy): New.
> 	(GOMP_OFFLOAD_run): Handle reverse offload.

Ok, thanks.

	Jakub