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[AMDGPU][Libomptarget] Move Kernel/Symbol info tables to RTLDeviceInfoTy
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Authored by pdhaliwal on May 18 2021, 7:24 AM.

Details

Summary

Two globals KernelInfoTable & SymbolInfoTable are moved
into RTLDeviceInfoTy class.
This builds on the top of D102691.
[2/2]

Diff Detail

Event Timeline

pdhaliwal created this revision.May 18 2021, 7:24 AM
pdhaliwal requested review of this revision.May 18 2021, 7:24 AM
Herald added a project: Restricted Project. · View Herald TranscriptMay 18 2021, 7:24 AM
JonChesterfield added a comment.EditedMay 18 2021, 7:59 AM

The vector<> part is for N GPUs, and each function call is for a specific GPU. So we never need to pass the whole vector along, only the element corresponding to that GPU.

I'd prefer we populate a new map for each code object and then merge them, instead of mutating the existing map, but I guess that's not a significant difference.

PopulateInfoTablesContext looks like a hazard - it's a struct holding references, which is usually a bad sign for lifetimes. If that's only used to pass data across the void* boundary, let's use a lambda instance instead.

PopulateInfoTablesContext looks like a hazard - it's a struct holding references, which is usually a bad sign for lifetimes. If that's only used to pass data across the void* boundary, let's use a lambda instance instead.

The capturing lambda won't work here so that's why I chose to use a struct of references.

pdhaliwal updated this revision to Diff 346404.May 19 2021, 4:18 AM

I could not find alternative to references in the PopulateInfoTablesContext. I could use pointers
but I don't see how that is different from having references.

Updated the patch to pass map directly instead of whole vector.

pdhaliwal updated this revision to Diff 346948.May 21 2021, 1:12 AM

Remove RegisterModuleFromMemory declaration from Runtime

openmp/libomptarget/plugins/amdgpu/impl/system.cpp
820–822

Minor point, output parameters at the end of the list is probably more common than at the start of the list for C++.

I'd rather pass mutable things by pointer, so the call site looks like function(42, &something_mutated), but that convention is from a different codebase to this one.

Better than either would be returning a pair<status, map> instead of mutating it in place. But given this change is moving from a global variable to a parameter, getting rid of the mutation at the same time seems a step too far for one patch.

994–995

Would lean towards dropping the void*, e.g. via D103030:

static hsa_status_t populate_InfoTables(hsa_executable_symbol_t symbol, 
  std::map<std::string, atl_kernel_info_t> &KernelInfoTable,
  std::map<std::string, atl_symbol_info_t> &SymbolInfoTable) {
openmp/libomptarget/plugins/amdgpu/src/rtl.cpp
89

This seems orthogonal to moving the global.

Also, looks like we now have declarations in rtl.cpp and definitions in atmi_interop_hsa.cpp, which seems bad as we lose the compiler checking that the call site matches the definition

Remove struct. Following D103030 approach.

Revert delete atmi_hsa_interop.h

foad removed a subscriber: foad.May 25 2021, 2:00 AM
pdhaliwal marked 2 inline comments as done.May 25 2021, 2:52 AM

except for the lost error check above, I think this is now a non-functional change. LG with that error path restored

openmp/libomptarget/plugins/amdgpu/impl/system.cpp
1128

lost an err = assignment and check here

openmp/libomptarget/plugins/amdgpu/src/rtl.cpp
499

This is dead - resize the vector will populate it with default constructed map<string>, and clear on a default constructed map is a no-op

572

The KernelInfoTable and SymbolInfoTable calls here are also dead. They're free store allocated memory, don't need to tear them down before closing hsa (unlike kernel arg pool, which contains pointers from hsa allocated memory)

passing by const& is much better than passing by &, I think we should do that in this patch

openmp/libomptarget/plugins/amdgpu/impl/atmi_interop_hsa.h
80–81

This is only called from one place, with info == HSA_EXECUTABLE_SYMBOL_INFO_KERNEL_KERNARG_SEGMENT_SIZE, so can be simplified to a map lookup. Orthogonal to this patch.

This and get_symbol_info only do lookups in the map so we should pass the map to them by const&.

Removed dead code and pass tables as const &

pdhaliwal marked 4 inline comments as done.May 25 2021, 11:49 PM
JonChesterfield accepted this revision.May 26 2021, 2:38 AM

LG, thanks!

This revision is now accepted and ready to land.May 26 2021, 2:38 AM
This revision was landed with ongoing or failed builds.May 26 2021, 3:02 AM
This revision was automatically updated to reflect the committed changes.