[inductor] logging meta data for inductor generated triton kernel (#120048)
I want to log metadata for inductor generated triton kernels for a couple of purposes
1. with these metadata, it should be convenient to find unaligned reduction kernels and try the idea here https://github.com/pytorch/pytorch/issues/119929 . I think it's nice to try on kernels that are used in real models
2. I'm thinking that based on the collected kernel metadata, I can build a simple offline tool by benchmarking each kernel with ncu and augment each kernel metadata with: latency, theoretical membw (estimated memory access / latency), and actually achieved membw. Hopefully this can point us to some good optimization opportunities.
Command:
```
TORCHINDUCTOR_CACHE_DIR=`realpath ~/inductor-caches/kernel-metadata-log` TORCHINDUCTOR_ENABLED_METRIC_TABLES=kernel_metadata TORCHINDUCTOR_BENCHMARK_KERNEL=1 TORCHINDUCTOR_UNIQUE_KERNEL_NAMES=1 time python benchmarks/dynamo/huggingface.py --backend inductor --amp --performance --training
```
The best practice here is to point inductor cache to a folder outside of /tmp so that one can always run the kernel again based on the path stored in kernel metadata. (folders under /tmp may get removed by the system)
Here is first 1000 rows of collected metadata for huggingface: https://gist.github.com/shunting314/cf4ebdaaaa7e852efcaa93524c868e5f
And here is the total 10K kernels collected for huggingface. The gist can not be rendered as a csv since it's too large: https://gist.github.com/shunting314/7f841528e2debdc2ae05dece4ac591be .
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120048
Approved by: https://github.com/jansel
