[MPS] Fix index_kernel for large tensors#158239
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atalman merged 1 commit intorelease/2.8from Jul 16, 2025
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Move `MetalShaderLibrary::bind_tensors` private method to OperatorUtils.h and extract `iter_tensor_offset` method, that returns an offset from the start of the storage associated with given tensor inside the iterator
Migrated `index`, `index_put[_accumulate][_serial]` to the new paradigm that does not require additional tensor for indices nor special handling for 32 vs 64-bit offset, which resulted in almost 2x perf gain for 2000x2000 tensor, see results below before
```
[------------------------------------------------------------ -----------------------------------------------------------]
| 11x50x50 | 11x100x100 | 11x500x500 | 11x1000x1000 | 11x2000x2000
1 threads: ----------------------------------------------------------------------------------------------------------------
__getitem__ (torch.int8, torch.int64) | 383.5 | 379.8 | 470.9 | 1232.9 | 4410.3
__getitem__ (torch.float16, torch.int64) | 379.6 | 354.5 | 533.2 | 1290.3 | 4442.2
__getitem__ (torch.float32, torch.int64) | 360.8 | 338.6 | 478.6 | 1348.9 | 4870.4
Times are in microseconds (us).
```
and after
```
[------------------------------------------------------------ -----------------------------------------------------------]
| 11x50x50 | 11x100x100 | 11x500x500 | 11x1000x1000 | 11x2000x2000
1 threads: ----------------------------------------------------------------------------------------------------------------
__getitem__ (torch.int8, torch.int64) | 349.8 | 330.5 | 432.6 | 764.5 | 1961.2
__getitem__ (torch.float16, torch.int64) | 342.5 | 330.7 | 434.7 | 741.0 | 1969.4
__getitem__ (torch.float32, torch.int64) | 332.2 | 326.1 | 445.4 | 751.3 | 1972.6
Times are in microseconds (us).
```
While migrating also fixed index_put_accumulate for boolean types, by using compare_and_exchange trick over uint
Fixes #153560
Pull Request resolved: #158064
Approved by: https://github.com/dcci
(cherry picked from commit beed033)
This was referenced Jul 14, 2025
🔗 Helpful Links🧪 See artifacts and rendered test results at hud.pytorch.org/pr/158239
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atalman
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Validated for release 2.8 by running tests changed in this PR |
tvukovic-amd
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Aug 20, 2025
[MPS] Fix `index_kernel` for large tensors (pytorch#158064) Move `MetalShaderLibrary::bind_tensors` private method to OperatorUtils.h and extract `iter_tensor_offset` method, that returns an offset from the start of the storage associated with given tensor inside the iterator Migrated `index`, `index_put[_accumulate][_serial]` to the new paradigm that does not require additional tensor for indices nor special handling for 32 vs 64-bit offset, which resulted in almost 2x perf gain for 2000x2000 tensor, see results below before ``` [------------------------------------------------------------ -----------------------------------------------------------] | 11x50x50 | 11x100x100 | 11x500x500 | 11x1000x1000 | 11x2000x2000 1 threads: ---------------------------------------------------------------------------------------------------------------- __getitem__ (torch.int8, torch.int64) | 383.5 | 379.8 | 470.9 | 1232.9 | 4410.3 __getitem__ (torch.float16, torch.int64) | 379.6 | 354.5 | 533.2 | 1290.3 | 4442.2 __getitem__ (torch.float32, torch.int64) | 360.8 | 338.6 | 478.6 | 1348.9 | 4870.4 Times are in microseconds (us). ``` and after ``` [------------------------------------------------------------ -----------------------------------------------------------] | 11x50x50 | 11x100x100 | 11x500x500 | 11x1000x1000 | 11x2000x2000 1 threads: ---------------------------------------------------------------------------------------------------------------- __getitem__ (torch.int8, torch.int64) | 349.8 | 330.5 | 432.6 | 764.5 | 1961.2 __getitem__ (torch.float16, torch.int64) | 342.5 | 330.7 | 434.7 | 741.0 | 1969.4 __getitem__ (torch.float32, torch.int64) | 332.2 | 326.1 | 445.4 | 751.3 | 1972.6 Times are in microseconds (us). ``` While migrating also fixed index_put_accumulate for boolean types, by using compare_and_exchange trick over uint Fixes pytorch#153560 Pull Request resolved: pytorch#158064 Approved by: https://github.com/dcci (cherry picked from commit beed033) Co-authored-by: Nikita Shulga <nikita.shulga@gmail.com>
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Stack from ghstack (oldest at bottom):
index_kernelfor large tensors #158064Move
MetalShaderLibrary::bind_tensorsprivate method to OperatorUtils.h and extractiter_tensor_offsetmethod, that returns an offset from the start of the storage associated with given tensor inside the iteratorMigrated
index,index_put[_accumulate][_serial]to the new paradigm that does not require additional tensor for indices nor special handling for 32 vs 64-bit offset, which resulted in almost 2x perf gain for 2000x2000 tensor, see results below beforeand after
While migrating also fixed index_put_accumulate for boolean types, by using compare_and_exchange trick over uint
Fixes #153560