ocl: follow-on for #846 #853
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This is further speeding up host memory allocation. So far, an OpenCL cl_mem object was created with no host-pointer and it was up to the OpenCL runtime to allocate the host memory. It turns out, this is horribly slow for GH200 stack (for unknown reasons). It was only helpful to mark such OpenCL allocated host memory as "not worth to transfer initially" (CL_MAP_WRITE_INVALIDATE_REGION); a bug in itself. Normally, allocating host memory by relying on the OpenCL runtime yields best performance at least when this memory is the origin/destination of a (PCIe-)transfer. However, GH200 SW stack seems to struggle with this idea. Introduced code path (covered by XHINTS) specific to Nvidia, which simply wraps a malloc'ed pointer (host memory). * Implemented malloc based c_dbcsr_acc_host_mem_allocate. * Introduced compile-time ACC_OPENCL_XHINTS. * Updated tuned parameters (Mi250 and GH200). * Removed unused function (m_getuid).
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This is further speeding up host memory allocation. So far, an OpenCL cl_mem object was created with no host-pointer and it was up to the OpenCL runtime to allocate the host memory. It turns out, this is horribly slow for GH200 stack (for unknown reasons). It was only helpful to mark such OpenCL allocated host memory as "not worth to transfer initially" (CL_MAP_WRITE_INVALIDATE_REGION); a bug in itself. Normally, allocating host memory by relying on the OpenCL runtime yields best performance at least when this memory is the origin/destination of a (PCIe-)transfer. However, GH200 SW stack seems to struggle with this idea. Introduced code path (covered by XHINTS) specific to Nvidia, which simply wraps a malloc'ed pointer (host memory).