Commit Graph

64 Commits

Author SHA1 Message Date
drisspg
127bd5a02d Add sparsity (#148513)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/148513
Approved by: https://github.com/danielvegamyhre
2025-03-07 01:47:52 +00:00
drisspg
e0f0db0105 updates to benchmarks (#144831)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/144831
Approved by: https://github.com/danielvegamyhre
2025-03-04 06:21:12 +00:00
Xuehai Pan
c73a92fbf5 [BE][CI] bump ruff to 0.9.2: multiline assert statements (#144546)
Reference: https://docs.astral.sh/ruff/formatter/black/#assert-statements

> Unlike Black, Ruff prefers breaking the message over breaking the assertion, similar to how both Ruff and Black prefer breaking the assignment value over breaking the assignment target:
>
> ```python
> # Input
> assert (
>     len(policy_types) >= priority + num_duplicates
> ), f"This tests needs at least {priority+num_duplicates} many types."
>
>
> # Black
> assert (
>     len(policy_types) >= priority + num_duplicates
> ), f"This tests needs at least {priority+num_duplicates} many types."
>
> # Ruff
> assert len(policy_types) >= priority + num_duplicates, (
>     f"This tests needs at least {priority + num_duplicates} many types."
> )
> ```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/144546
Approved by: https://github.com/malfet
2025-02-27 20:46:16 +00:00
Aaron Orenstein
07669ed960 PEP585 update - benchmarks tools torchgen (#145101)
This is one of a series of PRs to update us to PEP585 (changing Dict -> dict, List -> list, etc).  Most of the PRs were completely automated with RUFF as follows:

Since RUFF UP006 is considered an "unsafe" fix first we need to enable unsafe fixes:

```
--- a/tools/linter/adapters/ruff_linter.py
+++ b/tools/linter/adapters/ruff_linter.py
@@ -313,6 +313,7 @@
                     "ruff",
                     "check",
                     "--fix-only",
+                    "--unsafe-fixes",
                     "--exit-zero",
                     *([f"--config={config}"] if config else []),
                     "--stdin-filename",
```

Then we need to tell RUFF to allow UP006 (as a final PR once all of these have landed this will be made permanent):

```
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -40,7 +40,7 @@

 [tool.ruff]
-target-version = "py38"
+target-version = "py39"
 line-length = 88
 src = ["caffe2", "torch", "torchgen", "functorch", "test"]

@@ -87,7 +87,6 @@
     "SIM116", # Disable Use a dictionary instead of consecutive `if` statements
     "SIM117",
     "SIM118",
-    "UP006", # keep-runtime-typing
     "UP007", # keep-runtime-typing
 ]
 select = [
```

Finally running `lintrunner -a --take RUFF` will fix up the deprecated uses.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/145101
Approved by: https://github.com/bobrenjc93
2025-01-18 05:05:07 +00:00
bobrenjc93
fcf9dc3b11 Migrate from Tuple -> tuple in benchmarks (#144259)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/144259
Approved by: https://github.com/yanboliang
2025-01-07 04:09:52 +00:00
Oguz Ulgen
dc55704b48 Rename cache limit to recompile limit in configs (#143709)
This PR renames every cache_limit to recompile_limit via sed.

Old config options are maintained via Config(alias='xyz')

Pull Request resolved: https://github.com/pytorch/pytorch/pull/143709
Approved by: https://github.com/jansel
2024-12-22 10:03:57 +00:00
Tom Ritchford
f1cbf4b1b5 Enable ruff's unused variable checking everywhere in pytorch (#136965)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/136965
Approved by: https://github.com/cyyever, https://github.com/albanD
2024-12-22 02:33:11 +00:00
Joy Dong
a5ed499f6a FlexAttention Benchmark (#139665)
1. Add alibi, sliding window, tahn softcap, prefixLM, and document_mask from attn_gym to benchmark.

2. Add comparison to different SDPA backends & FAv2, FAv3, FAKV.

Dependent on https://github.com/pytorch/pytorch/pull/139639

Pull Request resolved: https://github.com/pytorch/pytorch/pull/139665
Approved by: https://github.com/drisspg
2024-12-20 17:52:24 +00:00
Tom Ritchford
498a7808ff Fix unused Python variables outside torch/ and test/ (#136359)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/136359
Approved by: https://github.com/albanD
2024-12-11 17:10:23 +00:00
Xuehai Pan
267f82b860 [BE] Format .ci/ / .github/ / benchmarks/ / functorch/ / tools/ / torchgen/ with ruff format (#132577)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/132577
Approved by: https://github.com/malfet
2024-10-11 18:30:26 +00:00
joydddd
4110cb6ba7 Add explicit GQA support. (#131559)
### tl;dr
This PR adds GQA support to higher order op `flex_attention`.

## Details
When `enable_gqa` is set to True, HOP `flex_attention(score_mod, query, key, value, block_mask, enable_gqa)` runs Group Query Attention(GQA), where the number of query heads (Hq) is a multiple of number of key/value heads (Hkv). Each group of query heads (`Hq//Hkv` heads) attends to a shared kv head.
Otherwise, `flex_attention` assumes Multi Head Attention (MHA) where the number of query heads is equal the number of kv heads.

The `score_mod` and `mask_mod` API are adapted accordingly to take `q_head` as head index.
```
def score_mod(score: torch.Tensor, batch: torch.Tensor, q_head: torch.Tensor, token_q: torch.Tensor, token_kv: torch.Tensor) -> torch.Tensor

def mask_mod(batch: torch.Tensor, q_head: torch.Tensor, token_q: torch.Tensor, token_kv: torch.Tensor) -> torch.Tensor
```

## Example
```python
import torch
from torch.nn.attention.flex_attention import flex_attention
from torch.nn.attention.flex_attention import create_block_mask

torch.manual_seed(0)

def query_key_value_clones(
    query: torch.Tensor,
    key: torch.Tensor,
    value: torch.Tensor,
    dtype: torch.dtype = None,
):
    """Clones the query, key, and value tensors and moves them to the specified dtype."""
    if dtype is None:
        dtype = query.dtype
    query_ref = query.clone().detach().to(dtype).requires_grad_(query.requires_grad)
    key_ref = key.clone().detach().to(dtype).requires_grad_(key.requires_grad)
    value_ref = value.clone().detach().to(dtype).requires_grad_(value.requires_grad)
    return query_ref, key_ref, value_ref

# Lets create some input tensors
# The input tensor has shape (batch_size, num_heads, seq_len, head_dim).
# query and key/value can have different num_heads and seq_len
# Here 8 query heads share one KV head.
query = torch.randn(2, 8, 2048, 64, device="cuda", dtype=torch.float32, requires_grad=True)
key = torch.randn(2, 2, 2048, 64, device="cuda", dtype=torch.float32, requires_grad=True)
value = torch.randn(2, 2, 2048, 64, device="cuda", dtype=torch.float32, requires_grad=True)

query1, key1, value1 = query_key_value_clones(query, key, value)

# Lets create a score_modification. We take alibi_bias as an example.
# score_mod takes batch index, query head index, query index, and key/value index.
def _generate_alibi_bias(num_kv_heads: int, num_q_heads: int):
    def _alibi_bias(
        score: torch.Tensor,
        b: torch.Tensor,
        hq: torch.Tensor,
        token_q: torch.Tensor,
        token_kv: torch.Tensor,
    ) -> torch.Tensor:
        # Let's calculate kv head from query head index
        group = num_q_heads // num_kv_heads
        hkv = hq // group

        scale = torch.exp2(-((hkv + 1) * 8.0 / num_kv_heads))
        return score + (token_kv - token_q) * scale

    return _alibi_bias

# Let's apply a casual mask on top of it
def causal_mask(b, h, q, kv):
    return q >= kv

# Generate a block mask for our new mask_mod function.
# The mask is broadcasted long head & batch dimensions.
block_mask = create_block_mask(causal_mask, B=1, H=1, Q_LEN=2048, KV_LEN=2048)

# Lets call flex_attention with our new score modification and block mask under eager mode.
output = flex_attention(query, key, value, score_mod=_generate_alibi_bias(2, 8), block_mask=block_mask, enable_gqa=True)

# Now lets compile flex_attention and run the flex_attention kernel.
compiled_flex_attention = torch.compile(flex_attention)
out_compiled = compiled_flex_attention(query1, key1, value1, score_mod=_generate_alibi_bias(2, 8), block_mask=block_mask, enable_gqa=True)

torch.testing.assert_close(output, out_compiled, atol=5e-2, rtol=2e-2)

```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/131559
Approved by: https://github.com/drisspg
2024-08-09 21:25:35 +00:00
Nicolas Macchioni
5cb05a82b4 [BC breaking] move benchmarking + prefer inductor path (#132827)
move benchmarking out of `torch._inductor.runtime.runtime_utils` and into `torch._inductor.runtime.benchmarking`, and prefer this path over directly accessing Triton's benchmarking

Fixes #ISSUE_NUMBER

Pull Request resolved: https://github.com/pytorch/pytorch/pull/132827
Approved by: https://github.com/eellison
2024-08-08 00:47:45 +00:00
drisspg
cb4d1bfb71 Clean up some tflop calc and add option for saving (#132799)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/132799
Approved by: https://github.com/BoyuanFeng
2024-08-07 00:19:42 +00:00
drisspg
2b86a7fcc7 fix printing of scores and mods names (#132424)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/132424
Approved by: https://github.com/Skylion007
2024-08-02 03:30:23 +00:00
joydddd
bdd83c4c7f Add Full block support to flex_decoding (#131404)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/131404
Approved by: https://github.com/yanboliang
2024-08-01 07:28:52 +00:00
joydddd
7f61324268 Add sparse block to flex_decoding kernel (#130884)
fix typo

Finish flex_decoding block sparse

Pull Request resolved: https://github.com/pytorch/pytorch/pull/130884
Approved by: https://github.com/drisspg
2024-07-24 20:30:25 +00:00
PyTorch MergeBot
6cbb1437c1 Revert "Add sparse block to flex_decoding kernel (#130884)"
This reverts commit 0bf59db6cc.

Reverted https://github.com/pytorch/pytorch/pull/130884 on behalf of https://github.com/atalman due to Sorry reverting test_causal_full_mask_vs_sdpa constantly failing on trunk ([comment](https://github.com/pytorch/pytorch/pull/130884#issuecomment-2244113663))
2024-07-23 02:10:14 +00:00
joydddd
0bf59db6cc Add sparse block to flex_decoding kernel (#130884)
fix typo

Finish flex_decoding block sparse

Pull Request resolved: https://github.com/pytorch/pytorch/pull/130884
Approved by: https://github.com/drisspg
2024-07-22 21:29:43 +00:00
joydddd
6d9f74f0af Add flex decoding benchmark (#130850)
ghstack-source-id: b4f26fb66ed47907b11580c8c853737959c58811
Pull Request resolved: https://github.com/pytorch/pytorch/pull/130788

Add benchmark for flex decoding.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/130850
Approved by: https://github.com/Chillee, https://github.com/drisspg
2024-07-18 18:09:25 +00:00
Xuehai Pan
c0ed38e644 [BE][Easy][3/19] enforce style for empty lines in import segments in benchmarks/ (#129754)
See https://github.com/pytorch/pytorch/pull/129751#issue-2380881501. Most changes are auto-generated by linter.

You can review these PRs via:

```bash
git diff --ignore-all-space --ignore-blank-lines HEAD~1
```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/129754
Approved by: https://github.com/ezyang
2024-07-17 14:34:42 +00:00
Alnis Murtovi
4b7ff35622 Fix flex_attention import in score_mod (#130906)
torch.nn.attention._flex_attention has been renamed to torch.nn.attention.flex_attention, so the import does not work currently.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/130906
Approved by: https://github.com/Chillee
2024-07-17 13:37:08 +00:00
chilli
da66e50e6e Added compile option to create_block_mask (#130106)
Compiling the `create_block_mask` function allows us to "materialize" extremely large masks. This would have been a 1 *trillion* element tensor if fully materialized.

```
print(do_bench(lambda: create_block_mask(causal_mask, 1, 1, 2**20, 2**20, _compiled=True)))
```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/130106
Approved by: https://github.com/yanboliang
ghstack dependencies: #130160
2024-07-06 08:09:56 +00:00
chilli
237c4e6163 Improved flexattention bwd perf + added configurations for benchmarks (#129013)
Before:
<img width="519" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/6f4a9b37-4aff-48d3-aaba-7e8e5a5bf0fb">

After:
<img width="541" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/423f179e-76f5-457b-8064-ee8a70247534">

After fixing strides:
![image](https://github.com/pytorch/pytorch/assets/6355099/58471587-404b-4bfc-b9b2-7546bdf53f54)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/129013
Approved by: https://github.com/drisspg, https://github.com/yanboliang
ghstack dependencies: #128938
2024-06-21 15:58:53 +00:00
PyTorch MergeBot
f73b451e78 Revert "Improved flexattention bwd perf + added configurations for benchmarks (#129013)"
This reverts commit ff89ebc50a.

Reverted https://github.com/pytorch/pytorch/pull/129013 on behalf of https://github.com/huydhn due to Sorry for reverting your change but one of the test_torchinductor_opinfo test starts to fail after this commit ff89ebc50a, I am reverting to see if it helps trunk recovers ([comment](https://github.com/pytorch/pytorch/pull/129013#issuecomment-2182042422))
2024-06-21 05:46:46 +00:00
chilli
ff89ebc50a Improved flexattention bwd perf + added configurations for benchmarks (#129013)
Before:
<img width="519" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/6f4a9b37-4aff-48d3-aaba-7e8e5a5bf0fb">

After:
<img width="541" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/423f179e-76f5-457b-8064-ee8a70247534">

After fixing strides:
![image](https://github.com/pytorch/pytorch/assets/6355099/58471587-404b-4bfc-b9b2-7546bdf53f54)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/129013
Approved by: https://github.com/drisspg, https://github.com/yanboliang
ghstack dependencies: #128938
2024-06-21 03:01:16 +00:00
PyTorch MergeBot
832fc35211 Revert "Improved flexattention bwd perf + added configurations for benchmarks (#129013)"
This reverts commit 6d2b3c90f1.

Reverted https://github.com/pytorch/pytorch/pull/129013 on behalf of https://github.com/ZainRizvi due to Sorry but this is causing a flexattention test to fail on ROCm. Can you please fix that test before remerging this in? See 6d2b3c90f1 for details ([comment](https://github.com/pytorch/pytorch/pull/129013#issuecomment-2181133070))
2024-06-20 16:51:41 +00:00
chilli
6d2b3c90f1 Improved flexattention bwd perf + added configurations for benchmarks (#129013)
Before:
<img width="519" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/6f4a9b37-4aff-48d3-aaba-7e8e5a5bf0fb">

After:
<img width="541" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/423f179e-76f5-457b-8064-ee8a70247534">

After fixing strides:
![image](https://github.com/pytorch/pytorch/assets/6355099/58471587-404b-4bfc-b9b2-7546bdf53f54)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/129013
Approved by: https://github.com/drisspg, https://github.com/yanboliang
ghstack dependencies: #128938
2024-06-20 05:15:48 +00:00
chilli
eb9f4da11e Modified template indexing to broadcast indices to out instead of mask and some other flexattention micro-opts (#128938)
For headdim=64 and headdim=128

Old:
<img width="656" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/2c5d1613-96dc-4300-8dc0-dccaef59e73c">

New:
<img width="644" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/730004a8-6d5f-46a5-82a0-2594feb5e192">

Note, this does regress headdim=256. We can unregress it by special casing `headdim=256`, but ehh.... we can do it later

Pull Request resolved: https://github.com/pytorch/pytorch/pull/128938
Approved by: https://github.com/drisspg
2024-06-19 03:41:22 +00:00
Xuehai Pan
26f4f10ac8 [5/N][Easy] fix typo for usort config in pyproject.toml (kown -> known): sort torch (#127126)
The `usort` config in `pyproject.toml` has no effect due to a typo. Fixing the typo make `usort` do more and generate the changes in the PR. Except `pyproject.toml`, all changes are generated by `lintrunner -a --take UFMT --all-files`.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/127126
Approved by: https://github.com/kit1980
2024-05-27 14:49:57 +00:00
PyTorch MergeBot
55c0ab2887 Revert "[5/N][Easy] fix typo for usort config in pyproject.toml (kown -> known): sort torch (#127126)"
This reverts commit 7763c83af6.

Reverted https://github.com/pytorch/pytorch/pull/127126 on behalf of https://github.com/XuehaiPan due to Broken CI ([comment](https://github.com/pytorch/pytorch/pull/127126#issuecomment-2133044286))
2024-05-27 09:22:08 +00:00
Xuehai Pan
7763c83af6 [5/N][Easy] fix typo for usort config in pyproject.toml (kown -> known): sort torch (#127126)
The `usort` config in `pyproject.toml` has no effect due to a typo. Fixing the typo make `usort` do more and generate the changes in the PR. Except `pyproject.toml`, all changes are generated by `lintrunner -a --take UFMT --all-files`.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/127126
Approved by: https://github.com/kit1980
ghstack dependencies: #127122, #127123, #127124, #127125
2024-05-27 04:22:18 +00:00
drisspg
762ce6f062 Add Lowering for FlexAttention Backwards (#125515)
# Summary
#### What does this PR do?
It enables Inductor to actually generate the fused flex attention kernel for the backwards

I did some other things along the way:
- Abstract out the 'build_subgraph_buffer' subroutine and make it reusable between flex attention and flex_attention backwards. In total we need too build 3 subgraphs for fwd + bwd. 1 for the fwd graph and then 2 in the bwd. The FAv2 algorithm recomputes the parts of the forward (more efficiently since we already have the row_max via logsumexp), therefore we need to inline both the fwd graph and the joint graph in the bwds kernel.
- The version of the backwards kernel is from a somewhat older version of the triton tutorial implementation. I think that we should update in a follow up to a newer version. Notably the blocks need to be square for this to work as currently implemented. I am sure there are many opportunities for optimization.
- I didnt correctly register the decomp table + IndexMode when I landed: https://github.com/pytorch/pytorch/pull/123902, this remedies that.
- The rel_bias helper func was reversed in terms of causality. I updated and then add a test specific for "future causal" attention.
- This PRs but the main point that I think still needs to be worked out is the store_output call. I have it hacked up to be 'fake' but I dont think we want to land that and likely want to just have a mutated 'dq' and a stored_output 'dk'
- I also needed to update the `TritonTemplateKernel` to actually accept multiple subgraphs (modifications)
- I updated the benchmark to also profile bwds performance

### Benchmark Numbers:
_The current implementation is not parallelizing over ctx length in the bwd_
FWD Speedups

| Type    |   Speedup | shape              | score_mod   | dtype          |
|---------|-----------|--------------------|-------------|----------------|
| Average |     0.991 |                    |             |                |
| Max     |     1.182 | (16, 16, 4096, 64) | noop        | torch.bfloat16 |
| Min     |     0.796 | (2, 16, 512, 256)  | head_bias   | torch.bfloat16 |

BWD Speedups

| Type    |   Speedup | shape              | score_mod   | dtype          |
|---------|-----------|--------------------|-------------|----------------|
| Average |     0.291 |                    |             |                |
| Max     |     0.652 | (8, 16, 512, 64)   | head_bias   | torch.bfloat16 |
| Min     |     0.073 | (2, 16, 4096, 128) | head_bias   | torch.bfloat16 |

<details>

<summary>Full Data</summary>

| shape               | score_mod     | dtype          |   fwd_eager_time |   fwd_compiled_time |   bwd_eager_time |   bwd_compiled_time |   fwd_speedup |   bwd_speedup |
|---------------------|---------------|----------------|------------------|---------------------|------------------|---------------------|---------------|---------------|
| (2, 16, 512, 64)    | noop          | torch.bfloat16 |           19.936 |              19.092 |           57.851 |             193.564 |         1.044 |         0.299 |
| (2, 16, 512, 64)    | causal_mask   | torch.bfloat16 |           19.955 |              19.497 |           57.662 |             206.278 |         1.024 |         0.280 |
| (2, 16, 512, 64)    | relative_bias | torch.bfloat16 |           19.455 |              21.297 |           57.674 |             195.219 |         0.913 |         0.295 |
| (2, 16, 512, 64)    | head_bias     | torch.bfloat16 |           19.958 |              21.289 |           57.674 |             193.859 |         0.938 |         0.298 |
| (2, 16, 512, 128)   | noop          | torch.bfloat16 |           28.157 |              28.615 |           82.831 |             454.211 |         0.984 |         0.182 |
| (2, 16, 512, 128)   | causal_mask   | torch.bfloat16 |           28.154 |              28.444 |           83.091 |             432.083 |         0.990 |         0.192 |
| (2, 16, 512, 128)   | relative_bias | torch.bfloat16 |           28.722 |              27.897 |           83.175 |             446.789 |         1.030 |         0.186 |
| (2, 16, 512, 128)   | head_bias     | torch.bfloat16 |           28.299 |              27.673 |           83.052 |             459.179 |         1.023 |         0.181 |
| (2, 16, 512, 256)   | noop          | torch.bfloat16 |           41.167 |              50.504 |          175.019 |            1083.545 |         0.815 |         0.162 |
| (2, 16, 512, 256)   | causal_mask   | torch.bfloat16 |           41.656 |              51.933 |          175.078 |            1171.176 |         0.802 |         0.149 |
| (2, 16, 512, 256)   | relative_bias | torch.bfloat16 |           41.697 |              50.722 |          175.159 |            1097.312 |         0.822 |         0.160 |
| (2, 16, 512, 256)   | head_bias     | torch.bfloat16 |           41.690 |              52.387 |          175.184 |            1097.336 |         0.796 |         0.160 |
| (2, 16, 1024, 64)   | noop          | torch.bfloat16 |           39.232 |              37.454 |          127.847 |             612.430 |         1.047 |         0.209 |
| (2, 16, 1024, 64)   | causal_mask   | torch.bfloat16 |           39.930 |              39.599 |          127.755 |             665.359 |         1.008 |         0.192 |
| (2, 16, 1024, 64)   | relative_bias | torch.bfloat16 |           39.417 |              41.304 |          127.902 |             614.990 |         0.954 |         0.208 |
| (2, 16, 1024, 64)   | head_bias     | torch.bfloat16 |           39.965 |              42.034 |          127.953 |             613.273 |         0.951 |         0.209 |
| (2, 16, 1024, 128)  | noop          | torch.bfloat16 |           63.964 |              71.024 |          226.510 |            1637.669 |         0.901 |         0.138 |
| (2, 16, 1024, 128)  | causal_mask   | torch.bfloat16 |           63.843 |              72.451 |          226.750 |            1558.949 |         0.881 |         0.145 |
| (2, 16, 1024, 128)  | relative_bias | torch.bfloat16 |           64.301 |              70.487 |          226.651 |            1610.063 |         0.912 |         0.141 |
| (2, 16, 1024, 128)  | head_bias     | torch.bfloat16 |           64.033 |              71.394 |          226.676 |            1668.511 |         0.897 |         0.136 |
| (2, 16, 1024, 256)  | noop          | torch.bfloat16 |          129.348 |             141.390 |          507.337 |            4405.175 |         0.915 |         0.115 |
| (2, 16, 1024, 256)  | causal_mask   | torch.bfloat16 |          129.538 |             145.680 |          507.178 |            4768.874 |         0.889 |         0.106 |
| (2, 16, 1024, 256)  | relative_bias | torch.bfloat16 |          129.438 |             142.782 |          507.004 |            4401.002 |         0.907 |         0.115 |
| (2, 16, 1024, 256)  | head_bias     | torch.bfloat16 |          129.058 |             146.242 |          507.547 |            4434.251 |         0.883 |         0.114 |
| (2, 16, 4096, 64)   | noop          | torch.bfloat16 |          481.606 |             409.120 |         1440.890 |           14147.269 |         1.177 |         0.102 |
| (2, 16, 4096, 64)   | causal_mask   | torch.bfloat16 |          480.227 |             438.847 |         1434.419 |           14973.386 |         1.094 |         0.096 |
| (2, 16, 4096, 64)   | relative_bias | torch.bfloat16 |          480.831 |             458.104 |         1432.935 |           14193.253 |         1.050 |         0.101 |
| (2, 16, 4096, 64)   | head_bias     | torch.bfloat16 |          480.749 |             452.497 |         1437.040 |           14084.869 |         1.062 |         0.102 |
| (2, 16, 4096, 128)  | noop          | torch.bfloat16 |          872.534 |             848.275 |         2600.895 |           35156.849 |         1.029 |         0.074 |
| (2, 16, 4096, 128)  | causal_mask   | torch.bfloat16 |          872.647 |             868.279 |         2587.581 |           31919.531 |         1.005 |         0.081 |
| (2, 16, 4096, 128)  | relative_bias | torch.bfloat16 |          871.484 |             827.644 |         2593.989 |           34805.634 |         1.053 |         0.075 |
| (2, 16, 4096, 128)  | head_bias     | torch.bfloat16 |          871.422 |             856.437 |         2602.482 |           35708.591 |         1.017 |         0.073 |
| (2, 16, 4096, 256)  | noop          | torch.bfloat16 |         1904.497 |            1758.183 |         6122.416 |           66754.593 |         1.083 |         0.092 |
| (2, 16, 4096, 256)  | causal_mask   | torch.bfloat16 |         1911.174 |            1762.821 |         6113.207 |           72759.392 |         1.084 |         0.084 |
| (2, 16, 4096, 256)  | relative_bias | torch.bfloat16 |         1911.254 |            1727.108 |         6123.530 |           66577.988 |         1.107 |         0.092 |
| (2, 16, 4096, 256)  | head_bias     | torch.bfloat16 |         1916.977 |            1801.804 |         6118.158 |           67359.680 |         1.064 |         0.091 |
| (8, 16, 512, 64)    | noop          | torch.bfloat16 |           44.984 |              43.974 |          170.276 |             262.259 |         1.023 |         0.649 |
| (8, 16, 512, 64)    | causal_mask   | torch.bfloat16 |           45.001 |              46.265 |          170.509 |             274.893 |         0.973 |         0.620 |
| (8, 16, 512, 64)    | relative_bias | torch.bfloat16 |           45.466 |              48.211 |          170.606 |             262.759 |         0.943 |         0.649 |
| (8, 16, 512, 64)    | head_bias     | torch.bfloat16 |           45.481 |              48.435 |          170.267 |             261.265 |         0.939 |         0.652 |
| (8, 16, 512, 128)   | noop          | torch.bfloat16 |           72.565 |              74.736 |          313.220 |             773.126 |         0.971 |         0.405 |
| (8, 16, 512, 128)   | causal_mask   | torch.bfloat16 |           72.015 |              75.755 |          313.311 |             775.513 |         0.951 |         0.404 |
| (8, 16, 512, 128)   | relative_bias | torch.bfloat16 |           72.105 |              74.189 |          313.806 |             769.238 |         0.972 |         0.408 |
| (8, 16, 512, 128)   | head_bias     | torch.bfloat16 |           72.005 |              74.364 |          313.509 |             775.237 |         0.968 |         0.404 |
| (8, 16, 512, 256)   | noop          | torch.bfloat16 |          138.656 |             165.453 |          663.707 |            2672.067 |         0.838 |         0.248 |
| (8, 16, 512, 256)   | causal_mask   | torch.bfloat16 |          139.096 |             172.613 |          663.593 |            2926.538 |         0.806 |         0.227 |
| (8, 16, 512, 256)   | relative_bias | torch.bfloat16 |          139.500 |             168.417 |          663.938 |            2658.629 |         0.828 |         0.250 |
| (8, 16, 512, 256)   | head_bias     | torch.bfloat16 |          139.776 |             173.549 |          662.920 |            2667.266 |         0.805 |         0.249 |
| (8, 16, 1024, 64)   | noop          | torch.bfloat16 |          134.883 |             125.004 |          484.706 |            1195.254 |         1.079 |         0.406 |
| (8, 16, 1024, 64)   | causal_mask   | torch.bfloat16 |          134.297 |             132.875 |          485.420 |            1234.953 |         1.011 |         0.393 |
| (8, 16, 1024, 64)   | relative_bias | torch.bfloat16 |          134.839 |             139.231 |          485.470 |            1198.556 |         0.968 |         0.405 |
| (8, 16, 1024, 64)   | head_bias     | torch.bfloat16 |          133.822 |             136.449 |          485.608 |            1189.198 |         0.981 |         0.408 |
| (8, 16, 1024, 128)  | noop          | torch.bfloat16 |          235.470 |             234.765 |          886.094 |            2662.944 |         1.003 |         0.333 |
| (8, 16, 1024, 128)  | causal_mask   | torch.bfloat16 |          236.305 |             241.382 |          886.293 |            2646.984 |         0.979 |         0.335 |
| (8, 16, 1024, 128)  | relative_bias | torch.bfloat16 |          236.414 |             233.980 |          885.250 |            2642.178 |         1.010 |         0.335 |
| (8, 16, 1024, 128)  | head_bias     | torch.bfloat16 |          237.176 |             239.040 |          885.754 |            2665.242 |         0.992 |         0.332 |
| (8, 16, 1024, 256)  | noop          | torch.bfloat16 |          504.445 |             517.855 |         1978.956 |            9592.906 |         0.974 |         0.206 |
| (8, 16, 1024, 256)  | causal_mask   | torch.bfloat16 |          502.428 |             536.002 |         1978.611 |           10607.342 |         0.937 |         0.187 |
| (8, 16, 1024, 256)  | relative_bias | torch.bfloat16 |          503.396 |             523.960 |         1977.993 |            9539.284 |         0.961 |         0.207 |
| (8, 16, 1024, 256)  | head_bias     | torch.bfloat16 |          503.818 |             536.014 |         1980.131 |            9576.262 |         0.940 |         0.207 |
| (8, 16, 4096, 64)   | noop          | torch.bfloat16 |         1970.139 |            1674.930 |         5750.940 |           16724.134 |         1.176 |         0.344 |
| (8, 16, 4096, 64)   | causal_mask   | torch.bfloat16 |         1959.036 |            1775.056 |         5780.512 |           17390.350 |         1.104 |         0.332 |
| (8, 16, 4096, 64)   | relative_bias | torch.bfloat16 |         1947.198 |            1773.869 |         5780.643 |           16779.699 |         1.098 |         0.345 |
| (8, 16, 4096, 64)   | head_bias     | torch.bfloat16 |         1963.935 |            1829.502 |         5780.018 |           16703.259 |         1.073 |         0.346 |
| (8, 16, 4096, 128)  | noop          | torch.bfloat16 |         3582.711 |            3362.623 |        10436.069 |           36415.565 |         1.065 |         0.287 |
| (8, 16, 4096, 128)  | causal_mask   | torch.bfloat16 |         3581.504 |            3499.472 |        10346.869 |           36164.959 |         1.023 |         0.286 |
| (8, 16, 4096, 128)  | relative_bias | torch.bfloat16 |         3589.779 |            3337.849 |        10529.621 |           36261.696 |         1.075 |         0.290 |
| (8, 16, 4096, 128)  | head_bias     | torch.bfloat16 |         3602.265 |            3436.444 |        10458.660 |           36507.790 |         1.048 |         0.286 |
| (8, 16, 4096, 256)  | noop          | torch.bfloat16 |         7695.923 |            7126.275 |        24643.009 |          140949.081 |         1.080 |         0.175 |
| (8, 16, 4096, 256)  | causal_mask   | torch.bfloat16 |         7679.939 |            7186.252 |        24538.105 |          157156.067 |         1.069 |         0.156 |
| (8, 16, 4096, 256)  | relative_bias | torch.bfloat16 |         7681.374 |            6994.832 |        24549.713 |          140077.179 |         1.098 |         0.175 |
| (8, 16, 4096, 256)  | head_bias     | torch.bfloat16 |         7679.822 |            7212.278 |        24627.823 |          140675.003 |         1.065 |         0.175 |
| (16, 16, 512, 64)   | noop          | torch.bfloat16 |           80.126 |              78.291 |          333.719 |             541.165 |         1.023 |         0.617 |
| (16, 16, 512, 64)   | causal_mask   | torch.bfloat16 |           80.065 |              81.696 |          333.779 |             551.113 |         0.980 |         0.606 |
| (16, 16, 512, 64)   | relative_bias | torch.bfloat16 |           80.138 |              86.715 |          333.364 |             542.118 |         0.924 |         0.615 |
| (16, 16, 512, 64)   | head_bias     | torch.bfloat16 |           80.415 |              85.204 |          333.294 |             536.840 |         0.944 |         0.621 |
| (16, 16, 512, 128)  | noop          | torch.bfloat16 |          134.964 |             138.025 |          607.093 |            1333.102 |         0.978 |         0.455 |
| (16, 16, 512, 128)  | causal_mask   | torch.bfloat16 |          134.192 |             141.523 |          606.269 |            1424.318 |         0.948 |         0.426 |
| (16, 16, 512, 128)  | relative_bias | torch.bfloat16 |          135.711 |             138.639 |          606.283 |            1327.974 |         0.979 |         0.457 |
| (16, 16, 512, 128)  | head_bias     | torch.bfloat16 |          135.552 |             140.555 |          607.107 |            1347.370 |         0.964 |         0.451 |
| (16, 16, 512, 256)  | noop          | torch.bfloat16 |          275.113 |             315.144 |         1301.583 |            5268.153 |         0.873 |         0.247 |
| (16, 16, 512, 256)  | causal_mask   | torch.bfloat16 |          274.867 |             328.106 |         1302.513 |            5770.594 |         0.838 |         0.226 |
| (16, 16, 512, 256)  | relative_bias | torch.bfloat16 |          276.052 |             321.770 |         1302.904 |            5241.920 |         0.858 |         0.249 |
| (16, 16, 512, 256)  | head_bias     | torch.bfloat16 |          271.409 |             328.839 |         1302.142 |            5266.037 |         0.825 |         0.247 |
| (16, 16, 1024, 64)  | noop          | torch.bfloat16 |          260.489 |             237.463 |          955.884 |            1817.558 |         1.097 |         0.526 |
| (16, 16, 1024, 64)  | causal_mask   | torch.bfloat16 |          262.378 |             254.350 |          955.280 |            1843.807 |         1.032 |         0.518 |
| (16, 16, 1024, 64)  | relative_bias | torch.bfloat16 |          261.338 |             268.253 |          956.038 |            1820.036 |         0.974 |         0.525 |
| (16, 16, 1024, 64)  | head_bias     | torch.bfloat16 |          262.153 |             264.156 |          956.023 |            1810.076 |         0.992 |         0.528 |
| (16, 16, 1024, 128) | noop          | torch.bfloat16 |          476.475 |             461.413 |         1760.578 |            4306.521 |         1.033 |         0.409 |
| (16, 16, 1024, 128) | causal_mask   | torch.bfloat16 |          473.794 |             479.178 |         1761.277 |            4619.439 |         0.989 |         0.381 |
| (16, 16, 1024, 128) | relative_bias | torch.bfloat16 |          473.839 |             463.282 |         1758.692 |            4290.562 |         1.023 |         0.410 |
| (16, 16, 1024, 128) | head_bias     | torch.bfloat16 |          472.979 |             472.896 |         1763.086 |            4367.931 |         1.000 |         0.404 |
| (16, 16, 1024, 256) | noop          | torch.bfloat16 |         1014.184 |            1026.764 |         3922.997 |           19104.147 |         0.988 |         0.205 |
| (16, 16, 1024, 256) | causal_mask   | torch.bfloat16 |         1013.217 |            1039.046 |         3928.382 |           21086.281 |         0.975 |         0.186 |
| (16, 16, 1024, 256) | relative_bias | torch.bfloat16 |         1008.519 |            1015.278 |         3922.133 |           18980.652 |         0.993 |         0.207 |
| (16, 16, 1024, 256) | head_bias     | torch.bfloat16 |         1011.360 |            1047.542 |         3931.245 |           19069.172 |         0.965 |         0.206 |
| (16, 16, 4096, 64)  | noop          | torch.bfloat16 |         3929.850 |            3325.667 |        11411.704 |           23344.280 |         1.182 |         0.489 |
| (16, 16, 4096, 64)  | causal_mask   | torch.bfloat16 |         3885.262 |            3581.544 |        11390.515 |           23725.639 |         1.085 |         0.480 |
| (16, 16, 4096, 64)  | relative_bias | torch.bfloat16 |         3865.737 |            3537.308 |        11489.901 |           23406.330 |         1.093 |         0.491 |
| (16, 16, 4096, 64)  | head_bias     | torch.bfloat16 |         3880.530 |            3665.249 |        11484.411 |           23299.496 |         1.059 |         0.493 |
| (16, 16, 4096, 128) | noop          | torch.bfloat16 |         7030.306 |            6745.715 |        20621.264 |           57464.096 |         1.042 |         0.359 |
| (16, 16, 4096, 128) | causal_mask   | torch.bfloat16 |         7095.414 |            7034.385 |        20410.656 |           61660.511 |         1.009 |         0.331 |
| (16, 16, 4096, 128) | relative_bias | torch.bfloat16 |         7084.779 |            6686.497 |        20315.161 |           57243.969 |         1.060 |         0.355 |
| (16, 16, 4096, 128) | head_bias     | torch.bfloat16 |         7075.367 |            6863.305 |        20494.385 |           58481.953 |         1.031 |         0.350 |
| (16, 16, 4096, 256) | noop          | torch.bfloat16 |        15612.741 |           14297.482 |        55306.847 |          281161.865 |         1.092 |         0.197 |
| (16, 16, 4096, 256) | causal_mask   | torch.bfloat16 |        15326.592 |           14263.878 |        55227.806 |          313063.232 |         1.075 |         0.176 |
| (16, 16, 4096, 256) | relative_bias | torch.bfloat16 |        15297.963 |           14007.379 |        54558.029 |          279529.175 |         1.092 |         0.195 |
| (16, 16, 4096, 256) | head_bias     | torch.bfloat16 |        15216.160 |           14276.027 |        55081.581 |          280996.826 |         1.066 |         0.196 |

</details>

Pull Request resolved: https://github.com/pytorch/pytorch/pull/125515
Approved by: https://github.com/Chillee
2024-05-17 00:41:55 +00:00
PyTorch MergeBot
0716f75cfb Revert "Add Lowering for FlexAttention Backwards (#125515)"
This reverts commit 95b9e981c3.

Reverted https://github.com/pytorch/pytorch/pull/125515 on behalf of https://github.com/huydhn due to Sorry for reverting your change but the newly added test runs out of memory 95b9e981c3 ([comment](https://github.com/pytorch/pytorch/pull/125515#issuecomment-2114084869))
2024-05-16 05:52:13 +00:00
drisspg
95b9e981c3 Add Lowering for FlexAttention Backwards (#125515)
# Summary
#### What does this PR do?
It enables Inductor to actually generate the fused flex attention kernel for the backwards

I did some other things along the way:
- Abstract out the 'build_subgraph_buffer' subroutine and make it reusable between flex attention and flex_attention backwards. In total we need too build 3 subgraphs for fwd + bwd. 1 for the fwd graph and then 2 in the bwd. The FAv2 algorithm recomputes the parts of the forward (more efficiently since we already have the row_max via logsumexp), therefore we need to inline both the fwd graph and the joint graph in the bwds kernel.
- The version of the backwards kernel is from a somewhat older version of the triton tutorial implementation. I think that we should update in a follow up to a newer version. Notably the blocks need to be square for this to work as currently implemented. I am sure there are many opportunities for optimization.
- I didnt correctly register the decomp table + IndexMode when I landed: https://github.com/pytorch/pytorch/pull/123902, this remedies that.
- The rel_bias helper func was reversed in terms of causality. I updated and then add a test specific for "future causal" attention.
- This PRs but the main point that I think still needs to be worked out is the store_output call. I have it hacked up to be 'fake' but I dont think we want to land that and likely want to just have a mutated 'dq' and a stored_output 'dk'
- I also needed to update the `TritonTemplateKernel` to actually accept multiple subgraphs (modifications)
- I updated the benchmark to also profile bwds performance

### Benchmark Numbers:
_The current implementation is not parallelizing over ctx length in the bwd_
FWD Speedups

| Type    |   Speedup | shape              | score_mod   | dtype          |
|---------|-----------|--------------------|-------------|----------------|
| Average |     0.991 |                    |             |                |
| Max     |     1.182 | (16, 16, 4096, 64) | noop        | torch.bfloat16 |
| Min     |     0.796 | (2, 16, 512, 256)  | head_bias   | torch.bfloat16 |

BWD Speedups

| Type    |   Speedup | shape              | score_mod   | dtype          |
|---------|-----------|--------------------|-------------|----------------|
| Average |     0.291 |                    |             |                |
| Max     |     0.652 | (8, 16, 512, 64)   | head_bias   | torch.bfloat16 |
| Min     |     0.073 | (2, 16, 4096, 128) | head_bias   | torch.bfloat16 |

<details>

<summary>Full Data</summary>

| shape               | score_mod     | dtype          |   fwd_eager_time |   fwd_compiled_time |   bwd_eager_time |   bwd_compiled_time |   fwd_speedup |   bwd_speedup |
|---------------------|---------------|----------------|------------------|---------------------|------------------|---------------------|---------------|---------------|
| (2, 16, 512, 64)    | noop          | torch.bfloat16 |           19.936 |              19.092 |           57.851 |             193.564 |         1.044 |         0.299 |
| (2, 16, 512, 64)    | causal_mask   | torch.bfloat16 |           19.955 |              19.497 |           57.662 |             206.278 |         1.024 |         0.280 |
| (2, 16, 512, 64)    | relative_bias | torch.bfloat16 |           19.455 |              21.297 |           57.674 |             195.219 |         0.913 |         0.295 |
| (2, 16, 512, 64)    | head_bias     | torch.bfloat16 |           19.958 |              21.289 |           57.674 |             193.859 |         0.938 |         0.298 |
| (2, 16, 512, 128)   | noop          | torch.bfloat16 |           28.157 |              28.615 |           82.831 |             454.211 |         0.984 |         0.182 |
| (2, 16, 512, 128)   | causal_mask   | torch.bfloat16 |           28.154 |              28.444 |           83.091 |             432.083 |         0.990 |         0.192 |
| (2, 16, 512, 128)   | relative_bias | torch.bfloat16 |           28.722 |              27.897 |           83.175 |             446.789 |         1.030 |         0.186 |
| (2, 16, 512, 128)   | head_bias     | torch.bfloat16 |           28.299 |              27.673 |           83.052 |             459.179 |         1.023 |         0.181 |
| (2, 16, 512, 256)   | noop          | torch.bfloat16 |           41.167 |              50.504 |          175.019 |            1083.545 |         0.815 |         0.162 |
| (2, 16, 512, 256)   | causal_mask   | torch.bfloat16 |           41.656 |              51.933 |          175.078 |            1171.176 |         0.802 |         0.149 |
| (2, 16, 512, 256)   | relative_bias | torch.bfloat16 |           41.697 |              50.722 |          175.159 |            1097.312 |         0.822 |         0.160 |
| (2, 16, 512, 256)   | head_bias     | torch.bfloat16 |           41.690 |              52.387 |          175.184 |            1097.336 |         0.796 |         0.160 |
| (2, 16, 1024, 64)   | noop          | torch.bfloat16 |           39.232 |              37.454 |          127.847 |             612.430 |         1.047 |         0.209 |
| (2, 16, 1024, 64)   | causal_mask   | torch.bfloat16 |           39.930 |              39.599 |          127.755 |             665.359 |         1.008 |         0.192 |
| (2, 16, 1024, 64)   | relative_bias | torch.bfloat16 |           39.417 |              41.304 |          127.902 |             614.990 |         0.954 |         0.208 |
| (2, 16, 1024, 64)   | head_bias     | torch.bfloat16 |           39.965 |              42.034 |          127.953 |             613.273 |         0.951 |         0.209 |
| (2, 16, 1024, 128)  | noop          | torch.bfloat16 |           63.964 |              71.024 |          226.510 |            1637.669 |         0.901 |         0.138 |
| (2, 16, 1024, 128)  | causal_mask   | torch.bfloat16 |           63.843 |              72.451 |          226.750 |            1558.949 |         0.881 |         0.145 |
| (2, 16, 1024, 128)  | relative_bias | torch.bfloat16 |           64.301 |              70.487 |          226.651 |            1610.063 |         0.912 |         0.141 |
| (2, 16, 1024, 128)  | head_bias     | torch.bfloat16 |           64.033 |              71.394 |          226.676 |            1668.511 |         0.897 |         0.136 |
| (2, 16, 1024, 256)  | noop          | torch.bfloat16 |          129.348 |             141.390 |          507.337 |            4405.175 |         0.915 |         0.115 |
| (2, 16, 1024, 256)  | causal_mask   | torch.bfloat16 |          129.538 |             145.680 |          507.178 |            4768.874 |         0.889 |         0.106 |
| (2, 16, 1024, 256)  | relative_bias | torch.bfloat16 |          129.438 |             142.782 |          507.004 |            4401.002 |         0.907 |         0.115 |
| (2, 16, 1024, 256)  | head_bias     | torch.bfloat16 |          129.058 |             146.242 |          507.547 |            4434.251 |         0.883 |         0.114 |
| (2, 16, 4096, 64)   | noop          | torch.bfloat16 |          481.606 |             409.120 |         1440.890 |           14147.269 |         1.177 |         0.102 |
| (2, 16, 4096, 64)   | causal_mask   | torch.bfloat16 |          480.227 |             438.847 |         1434.419 |           14973.386 |         1.094 |         0.096 |
| (2, 16, 4096, 64)   | relative_bias | torch.bfloat16 |          480.831 |             458.104 |         1432.935 |           14193.253 |         1.050 |         0.101 |
| (2, 16, 4096, 64)   | head_bias     | torch.bfloat16 |          480.749 |             452.497 |         1437.040 |           14084.869 |         1.062 |         0.102 |
| (2, 16, 4096, 128)  | noop          | torch.bfloat16 |          872.534 |             848.275 |         2600.895 |           35156.849 |         1.029 |         0.074 |
| (2, 16, 4096, 128)  | causal_mask   | torch.bfloat16 |          872.647 |             868.279 |         2587.581 |           31919.531 |         1.005 |         0.081 |
| (2, 16, 4096, 128)  | relative_bias | torch.bfloat16 |          871.484 |             827.644 |         2593.989 |           34805.634 |         1.053 |         0.075 |
| (2, 16, 4096, 128)  | head_bias     | torch.bfloat16 |          871.422 |             856.437 |         2602.482 |           35708.591 |         1.017 |         0.073 |
| (2, 16, 4096, 256)  | noop          | torch.bfloat16 |         1904.497 |            1758.183 |         6122.416 |           66754.593 |         1.083 |         0.092 |
| (2, 16, 4096, 256)  | causal_mask   | torch.bfloat16 |         1911.174 |            1762.821 |         6113.207 |           72759.392 |         1.084 |         0.084 |
| (2, 16, 4096, 256)  | relative_bias | torch.bfloat16 |         1911.254 |            1727.108 |         6123.530 |           66577.988 |         1.107 |         0.092 |
| (2, 16, 4096, 256)  | head_bias     | torch.bfloat16 |         1916.977 |            1801.804 |         6118.158 |           67359.680 |         1.064 |         0.091 |
| (8, 16, 512, 64)    | noop          | torch.bfloat16 |           44.984 |              43.974 |          170.276 |             262.259 |         1.023 |         0.649 |
| (8, 16, 512, 64)    | causal_mask   | torch.bfloat16 |           45.001 |              46.265 |          170.509 |             274.893 |         0.973 |         0.620 |
| (8, 16, 512, 64)    | relative_bias | torch.bfloat16 |           45.466 |              48.211 |          170.606 |             262.759 |         0.943 |         0.649 |
| (8, 16, 512, 64)    | head_bias     | torch.bfloat16 |           45.481 |              48.435 |          170.267 |             261.265 |         0.939 |         0.652 |
| (8, 16, 512, 128)   | noop          | torch.bfloat16 |           72.565 |              74.736 |          313.220 |             773.126 |         0.971 |         0.405 |
| (8, 16, 512, 128)   | causal_mask   | torch.bfloat16 |           72.015 |              75.755 |          313.311 |             775.513 |         0.951 |         0.404 |
| (8, 16, 512, 128)   | relative_bias | torch.bfloat16 |           72.105 |              74.189 |          313.806 |             769.238 |         0.972 |         0.408 |
| (8, 16, 512, 128)   | head_bias     | torch.bfloat16 |           72.005 |              74.364 |          313.509 |             775.237 |         0.968 |         0.404 |
| (8, 16, 512, 256)   | noop          | torch.bfloat16 |          138.656 |             165.453 |          663.707 |            2672.067 |         0.838 |         0.248 |
| (8, 16, 512, 256)   | causal_mask   | torch.bfloat16 |          139.096 |             172.613 |          663.593 |            2926.538 |         0.806 |         0.227 |
| (8, 16, 512, 256)   | relative_bias | torch.bfloat16 |          139.500 |             168.417 |          663.938 |            2658.629 |         0.828 |         0.250 |
| (8, 16, 512, 256)   | head_bias     | torch.bfloat16 |          139.776 |             173.549 |          662.920 |            2667.266 |         0.805 |         0.249 |
| (8, 16, 1024, 64)   | noop          | torch.bfloat16 |          134.883 |             125.004 |          484.706 |            1195.254 |         1.079 |         0.406 |
| (8, 16, 1024, 64)   | causal_mask   | torch.bfloat16 |          134.297 |             132.875 |          485.420 |            1234.953 |         1.011 |         0.393 |
| (8, 16, 1024, 64)   | relative_bias | torch.bfloat16 |          134.839 |             139.231 |          485.470 |            1198.556 |         0.968 |         0.405 |
| (8, 16, 1024, 64)   | head_bias     | torch.bfloat16 |          133.822 |             136.449 |          485.608 |            1189.198 |         0.981 |         0.408 |
| (8, 16, 1024, 128)  | noop          | torch.bfloat16 |          235.470 |             234.765 |          886.094 |            2662.944 |         1.003 |         0.333 |
| (8, 16, 1024, 128)  | causal_mask   | torch.bfloat16 |          236.305 |             241.382 |          886.293 |            2646.984 |         0.979 |         0.335 |
| (8, 16, 1024, 128)  | relative_bias | torch.bfloat16 |          236.414 |             233.980 |          885.250 |            2642.178 |         1.010 |         0.335 |
| (8, 16, 1024, 128)  | head_bias     | torch.bfloat16 |          237.176 |             239.040 |          885.754 |            2665.242 |         0.992 |         0.332 |
| (8, 16, 1024, 256)  | noop          | torch.bfloat16 |          504.445 |             517.855 |         1978.956 |            9592.906 |         0.974 |         0.206 |
| (8, 16, 1024, 256)  | causal_mask   | torch.bfloat16 |          502.428 |             536.002 |         1978.611 |           10607.342 |         0.937 |         0.187 |
| (8, 16, 1024, 256)  | relative_bias | torch.bfloat16 |          503.396 |             523.960 |         1977.993 |            9539.284 |         0.961 |         0.207 |
| (8, 16, 1024, 256)  | head_bias     | torch.bfloat16 |          503.818 |             536.014 |         1980.131 |            9576.262 |         0.940 |         0.207 |
| (8, 16, 4096, 64)   | noop          | torch.bfloat16 |         1970.139 |            1674.930 |         5750.940 |           16724.134 |         1.176 |         0.344 |
| (8, 16, 4096, 64)   | causal_mask   | torch.bfloat16 |         1959.036 |            1775.056 |         5780.512 |           17390.350 |         1.104 |         0.332 |
| (8, 16, 4096, 64)   | relative_bias | torch.bfloat16 |         1947.198 |            1773.869 |         5780.643 |           16779.699 |         1.098 |         0.345 |
| (8, 16, 4096, 64)   | head_bias     | torch.bfloat16 |         1963.935 |            1829.502 |         5780.018 |           16703.259 |         1.073 |         0.346 |
| (8, 16, 4096, 128)  | noop          | torch.bfloat16 |         3582.711 |            3362.623 |        10436.069 |           36415.565 |         1.065 |         0.287 |
| (8, 16, 4096, 128)  | causal_mask   | torch.bfloat16 |         3581.504 |            3499.472 |        10346.869 |           36164.959 |         1.023 |         0.286 |
| (8, 16, 4096, 128)  | relative_bias | torch.bfloat16 |         3589.779 |            3337.849 |        10529.621 |           36261.696 |         1.075 |         0.290 |
| (8, 16, 4096, 128)  | head_bias     | torch.bfloat16 |         3602.265 |            3436.444 |        10458.660 |           36507.790 |         1.048 |         0.286 |
| (8, 16, 4096, 256)  | noop          | torch.bfloat16 |         7695.923 |            7126.275 |        24643.009 |          140949.081 |         1.080 |         0.175 |
| (8, 16, 4096, 256)  | causal_mask   | torch.bfloat16 |         7679.939 |            7186.252 |        24538.105 |          157156.067 |         1.069 |         0.156 |
| (8, 16, 4096, 256)  | relative_bias | torch.bfloat16 |         7681.374 |            6994.832 |        24549.713 |          140077.179 |         1.098 |         0.175 |
| (8, 16, 4096, 256)  | head_bias     | torch.bfloat16 |         7679.822 |            7212.278 |        24627.823 |          140675.003 |         1.065 |         0.175 |
| (16, 16, 512, 64)   | noop          | torch.bfloat16 |           80.126 |              78.291 |          333.719 |             541.165 |         1.023 |         0.617 |
| (16, 16, 512, 64)   | causal_mask   | torch.bfloat16 |           80.065 |              81.696 |          333.779 |             551.113 |         0.980 |         0.606 |
| (16, 16, 512, 64)   | relative_bias | torch.bfloat16 |           80.138 |              86.715 |          333.364 |             542.118 |         0.924 |         0.615 |
| (16, 16, 512, 64)   | head_bias     | torch.bfloat16 |           80.415 |              85.204 |          333.294 |             536.840 |         0.944 |         0.621 |
| (16, 16, 512, 128)  | noop          | torch.bfloat16 |          134.964 |             138.025 |          607.093 |            1333.102 |         0.978 |         0.455 |
| (16, 16, 512, 128)  | causal_mask   | torch.bfloat16 |          134.192 |             141.523 |          606.269 |            1424.318 |         0.948 |         0.426 |
| (16, 16, 512, 128)  | relative_bias | torch.bfloat16 |          135.711 |             138.639 |          606.283 |            1327.974 |         0.979 |         0.457 |
| (16, 16, 512, 128)  | head_bias     | torch.bfloat16 |          135.552 |             140.555 |          607.107 |            1347.370 |         0.964 |         0.451 |
| (16, 16, 512, 256)  | noop          | torch.bfloat16 |          275.113 |             315.144 |         1301.583 |            5268.153 |         0.873 |         0.247 |
| (16, 16, 512, 256)  | causal_mask   | torch.bfloat16 |          274.867 |             328.106 |         1302.513 |            5770.594 |         0.838 |         0.226 |
| (16, 16, 512, 256)  | relative_bias | torch.bfloat16 |          276.052 |             321.770 |         1302.904 |            5241.920 |         0.858 |         0.249 |
| (16, 16, 512, 256)  | head_bias     | torch.bfloat16 |          271.409 |             328.839 |         1302.142 |            5266.037 |         0.825 |         0.247 |
| (16, 16, 1024, 64)  | noop          | torch.bfloat16 |          260.489 |             237.463 |          955.884 |            1817.558 |         1.097 |         0.526 |
| (16, 16, 1024, 64)  | causal_mask   | torch.bfloat16 |          262.378 |             254.350 |          955.280 |            1843.807 |         1.032 |         0.518 |
| (16, 16, 1024, 64)  | relative_bias | torch.bfloat16 |          261.338 |             268.253 |          956.038 |            1820.036 |         0.974 |         0.525 |
| (16, 16, 1024, 64)  | head_bias     | torch.bfloat16 |          262.153 |             264.156 |          956.023 |            1810.076 |         0.992 |         0.528 |
| (16, 16, 1024, 128) | noop          | torch.bfloat16 |          476.475 |             461.413 |         1760.578 |            4306.521 |         1.033 |         0.409 |
| (16, 16, 1024, 128) | causal_mask   | torch.bfloat16 |          473.794 |             479.178 |         1761.277 |            4619.439 |         0.989 |         0.381 |
| (16, 16, 1024, 128) | relative_bias | torch.bfloat16 |          473.839 |             463.282 |         1758.692 |            4290.562 |         1.023 |         0.410 |
| (16, 16, 1024, 128) | head_bias     | torch.bfloat16 |          472.979 |             472.896 |         1763.086 |            4367.931 |         1.000 |         0.404 |
| (16, 16, 1024, 256) | noop          | torch.bfloat16 |         1014.184 |            1026.764 |         3922.997 |           19104.147 |         0.988 |         0.205 |
| (16, 16, 1024, 256) | causal_mask   | torch.bfloat16 |         1013.217 |            1039.046 |         3928.382 |           21086.281 |         0.975 |         0.186 |
| (16, 16, 1024, 256) | relative_bias | torch.bfloat16 |         1008.519 |            1015.278 |         3922.133 |           18980.652 |         0.993 |         0.207 |
| (16, 16, 1024, 256) | head_bias     | torch.bfloat16 |         1011.360 |            1047.542 |         3931.245 |           19069.172 |         0.965 |         0.206 |
| (16, 16, 4096, 64)  | noop          | torch.bfloat16 |         3929.850 |            3325.667 |        11411.704 |           23344.280 |         1.182 |         0.489 |
| (16, 16, 4096, 64)  | causal_mask   | torch.bfloat16 |         3885.262 |            3581.544 |        11390.515 |           23725.639 |         1.085 |         0.480 |
| (16, 16, 4096, 64)  | relative_bias | torch.bfloat16 |         3865.737 |            3537.308 |        11489.901 |           23406.330 |         1.093 |         0.491 |
| (16, 16, 4096, 64)  | head_bias     | torch.bfloat16 |         3880.530 |            3665.249 |        11484.411 |           23299.496 |         1.059 |         0.493 |
| (16, 16, 4096, 128) | noop          | torch.bfloat16 |         7030.306 |            6745.715 |        20621.264 |           57464.096 |         1.042 |         0.359 |
| (16, 16, 4096, 128) | causal_mask   | torch.bfloat16 |         7095.414 |            7034.385 |        20410.656 |           61660.511 |         1.009 |         0.331 |
| (16, 16, 4096, 128) | relative_bias | torch.bfloat16 |         7084.779 |            6686.497 |        20315.161 |           57243.969 |         1.060 |         0.355 |
| (16, 16, 4096, 128) | head_bias     | torch.bfloat16 |         7075.367 |            6863.305 |        20494.385 |           58481.953 |         1.031 |         0.350 |
| (16, 16, 4096, 256) | noop          | torch.bfloat16 |        15612.741 |           14297.482 |        55306.847 |          281161.865 |         1.092 |         0.197 |
| (16, 16, 4096, 256) | causal_mask   | torch.bfloat16 |        15326.592 |           14263.878 |        55227.806 |          313063.232 |         1.075 |         0.176 |
| (16, 16, 4096, 256) | relative_bias | torch.bfloat16 |        15297.963 |           14007.379 |        54558.029 |          279529.175 |         1.092 |         0.195 |
| (16, 16, 4096, 256) | head_bias     | torch.bfloat16 |        15216.160 |           14276.027 |        55081.581 |          280996.826 |         1.066 |         0.196 |

</details>

Pull Request resolved: https://github.com/pytorch/pytorch/pull/125515
Approved by: https://github.com/Chillee
2024-05-16 03:14:27 +00:00
Yanbo Liang
dfab69fdf1 [Inductor] Flex attention supports dynamic shape (#125994)
## static shapes perf
```
| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod   | dtype          |
|---------|-----------|--------------|-------------|-------------|-------------|------------|-------------|----------------|
| Average |     0.692 |              |             |             |             |            |             |                |
| Max     |     0.855 |           16 |          16 |        4096 |        4096 |         64 | head_bias   | torch.bfloat16 |
| Min     |     0.419 |            8 |          16 |         512 |         512 |        256 | noop        | torch.bfloat16 |
```
## dynamic shapes perf
```
| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod     | dtype          |
|---------|-----------|--------------|-------------|-------------|-------------|------------|---------------|----------------|
| Average |     0.670 |              |             |             |             |            |               |                |
| Max     |     0.864 |           16 |          16 |        4096 |        4096 |         64 | relative_bias | torch.bfloat16 |
| Min     |     0.376 |            8 |          16 |         512 |         512 |        256 | relative_bias | torch.bfloat16 |
```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/125994
Approved by: https://github.com/Chillee
2024-05-15 04:43:24 +00:00
Yanbo Liang
3b5f6b10ad [Inductor] default block size for head_dim = 256 for flex attention (#125380)
## H100
### torch.bfloat16
No major change, as expected.
```
| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod   | dtype          |
|---------|-----------|--------------|-------------|-------------|-------------|------------|-------------|----------------|
| Average |     1.122 |              |             |             |             |            |             |                |
| Max     |     1.437 |            1 |          16 |         512 |         512 |        128 | head_bias   | torch.bfloat16 |
| Min     |     0.895 |            1 |          16 |        1024 |        1024 |         64 | head_bias   | torch.bfloat16 |
```
### torch.float32
Before: OOM when ```head_dim``` = 256
After:
```
| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod   | dtype         |
|---------|-----------|--------------|-------------|-------------|-------------|------------|-------------|---------------|
| Average |     2.231 |              |             |             |             |            |             |               |
| Max     |     3.760 |           16 |          16 |        4096 |        4096 |         64 | noop        | torch.float32 |
| Min     |     1.532 |            1 |          16 |         512 |         512 |        256 | causal_mask | torch.float32 |
```

## A100
### torch.bfloat16
Before:
```
| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod     | dtype          |
|---------|-----------|--------------|-------------|-------------|-------------|------------|---------------|----------------|
| Average |     0.587 |              |             |             |             |            |               |                |
| Max     |     0.960 |            1 |          16 |         512 |         512 |         64 | noop          | torch.bfloat16 |
| Min     |     0.017 |            8 |          16 |        4096 |        4096 |        256 | relative_bias | torch.bfloat16 |
```
After:
```
| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod   | dtype          |
|---------|-----------|--------------|-------------|-------------|-------------|------------|-------------|----------------|
| Average |     0.756 |              |             |             |             |            |             |                |
| Max     |     0.931 |            1 |          16 |         512 |         512 |         64 | noop        | torch.bfloat16 |
| Min     |     0.467 |           16 |          16 |        1024 |        1024 |        256 | noop        | torch.bfloat16 |
```

### torch.float32
Before: OOM when ```head_dim``` = 256
After:
```
| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod   | dtype         |
|---------|-----------|--------------|-------------|-------------|-------------|------------|-------------|---------------|
| Average |     2.386 |              |             |             |             |            |             |               |
| Max     |     7.584 |           16 |          16 |         512 |         512 |         64 | noop        | torch.float32 |
| Min     |     0.948 |            1 |          16 |         512 |         512 |        256 | causal_mask | torch.float32 |
```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/125380
Approved by: https://github.com/drisspg
2024-05-02 22:51:07 +00:00
drisspg
25691558d9 Change templated_attention -> flex_attention (#125251)
# Summary

Change all the names

Pull Request resolved: https://github.com/pytorch/pytorch/pull/125251
Approved by: https://github.com/Chillee, https://github.com/yanboliang
2024-05-01 01:08:48 +00:00
Yanbo Liang
80046c315b Add templated attention BLOCK_M & BLOCK_N default size for different head_dim (#125139)
Run different head_dims [64, 128], which are the most popular ones across major GPT models.
Enumerate different ```BLOCK_M``` and ```BLOCK_N``` candidates [16, 32, 64, 128], and get the best config as default one.

## Before
```
| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod   | dtype          |
|---------|-----------|--------------|-------------|-------------|-------------|------------|-------------|----------------|
| Average |     0.704 |              |             |             |             |            |             |                |
| Max     |     0.953 |            1 |          16 |         512 |         512 |         64 | noop        | torch.bfloat16 |
| Min     |     0.482 |            1 |          16 |        4096 |        4096 |        128 | causal_mask | torch.bfloat16 |
```
## After
```
| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod   | dtype          |
|---------|-----------|--------------|-------------|-------------|-------------|------------|-------------|----------------|
| Average |     0.823 |              |             |             |             |            |             |                |
| Max     |     0.926 |            1 |          16 |         512 |         512 |         64 | noop        | torch.bfloat16 |
| Min     |     0.723 |            1 |          16 |         512 |         512 |        128 | causal_mask | torch.bfloat16 |
```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/125139
Approved by: https://github.com/Chillee
2024-04-30 17:40:44 +00:00
Aaron Orenstein
a8574a9719 Fix global flake8 issues (#124771)
Prior to this `lintrunner --all-files --take FLAKE8` failed.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/124771
Approved by: https://github.com/Skylion007
ghstack dependencies: #124428
2024-04-26 15:35:53 +00:00
PyTorch MergeBot
1ac60484c1 Revert "Fix global flake8 issues (#124771)"
This reverts commit f01275934b.

Reverted https://github.com/pytorch/pytorch/pull/124771 on behalf of https://github.com/jeanschmidt due to Unfortunately, I needed to revert #123735 and this one depends on it. So please check if there are no merge conflicts or breakages and feel free to merge this PR again ([comment](https://github.com/pytorch/pytorch/pull/124428#issuecomment-2078699836))
2024-04-26 06:15:17 +00:00
Aaron Orenstein
f01275934b Fix global flake8 issues (#124771)
Prior to this `lintrunner --all-files --take FLAKE8` failed.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/124771
Approved by: https://github.com/Skylion007
ghstack dependencies: #124428
2024-04-25 14:25:00 +00:00
chilli
e620c3e814 Optimized templated attention to use exp2 (#124356)
0.705 (vs. FA2) to 0.860 after this change.

<img width="1270" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/d58f57ba-e50e-44ea-8a8a-4f13b8650adf">

to

<img width="1277" alt="image" src="https://github.com/pytorch/pytorch/assets/6355099/f1945b67-0cfc-463c-a2f6-5812b90677fe">

Pull Request resolved: https://github.com/pytorch/pytorch/pull/124356
Approved by: https://github.com/drisspg
2024-04-19 01:58:19 +00:00
drisspg
f4e2a226aa ScoreMod API (#121845)
# Summary

This PR adds a new higher-order_op: `templated_attention`.  This op is designed to extend the functionality of torch.nn.fucntional.scaled_dot_product_attention.  PyTorch has efficient pre-written fused-attention kernels. However, users want to modify how scores are computed (a substep inside attention) -- this traditionally requires the user to write their own attention kernel. One such modification to attention scores that is not currently supported by the top level SDPA op is:[ Attention with Linear Biases (ALiBi](https://arxiv.org/abs/2108.12409)).

This higher-order op will instead accept a callable( 'score_mod') function that is through torch.compile will be used to create an efficient attention kernel instantiation.

### Details

This HOP utilizes the existing fx and HOP infra to capture and convert the User `score-mod` function and convert to an FX graph module. Inductor then consumes this HOP that has a `ir.Subgraph` input. It will inline this lowered subgraph into a triton kernel which performs fused attention with the modification to the scores matrix inlined.

### API

The API for a score_mod function should be as follows:

```Python
def score_mod(score: torch.Tensor, batch: torch.Tensor, head: torch.Tensor, token_1: torch.Tensor, token_kv: torch.Tensor) -> torch.Tensor
```

This function receives five parameters:

- `score`: A scalar tensor representing the attention score, with the same data type and device as the query, key, and value tensors.
- `batch`, `head`, `seq_len_q`, `seq_len_kv`: Scalar tensors indicating the batch index, head index, query index, and key/value index, respectively, with torch.int data type and located on the same device as the score tensor.

Consider inputs query, key, value of shapes (2, 4, 16, 8), leading to an intermediate attention score matrix of shape (2, 4, 16, 16)

The score_mod function will be vectorized over each element of this matrix. For instance, modifying the score at the position corresponding to the 0th batch, 2nd head, between the 8th query and the 9th key element, would be invoked as:

```Python
score_mod(score[0,2,8,9], torch.tensor(0), torch.tensor(2), torch.tensor(8), torch.tensor(9))
```

### Examples
```Python
import torch
from torch.nn.attention.templated_attention import templated_attention

torch.manual_seed(0)

# Lets create some input tensors
# The input tensor has shape (batch_size, num_heads, seq_len, head_dim)
query = torch.randn(8, 8, 2048, 64, device="cuda", dtype=torch.float32)
key = torch.randn(8, 8, 2048, 64, device="cuda", dtype=torch.float32)
value = torch.randn(8, 8, 2048, 64, device="cuda", dtype=torch.float32)

# Lets create a fun new score_modification! I will call this
# Checkerboard. It will reduce the score for neighboring tokens (1 step apart)
# in the sequence. And increase the score for tokens 2 steps apart. For everything
# else, the score will remain the same.

def checkerboard(score, batch, head, token_q, token_kv):
    score = torch.where(torch.abs(token_kv - token_q) == 1, score * 0.5, score)
    score = torch.where(torch.abs(token_kv - token_q) == 2, score * 2.0, score)
    return score

# Lets call templated_attention with this new score modification
output = templated_attention(query, key, value, score_mod=checkerboard)

compiled_templated_attention = torch.compile(templated_attention)
out_compiled = compiled_templated_attention(query, key, value, score_mod=checkerboard)

torch.testing.assert_close(output, out_compiled, atol=2e-2, rtol=2e-2)
```

### Future Work
- This PR is currently only forward only. However the triton kernel for backwards where score_modifications to not rely on external buffers has been explored here: https://github.com/drisspg/transformer_nuggets/blob/main/transformer_nuggets/flash/flash_attention.py
- Kernel Improvements; There are has been some larger updates to the fused attention implementation that Triton uses in its tutorials. The implementation of this kernel is based on a prior version and should be updated.
- We may want to unify this API under the top level SDPA API and leave that as a follow up once this is more stable
- Should we error on CPU?
- There are some issues with dynamic shapes
- Capturing of free variables and lifting to inputs to the subgraph is not working correctly today

### Performance
Comparisons generated by this benchmark:

| Type    |   Speedup |   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod     | dtype          |
|---------|-----------|--------------|-------------|-------------|-------------|------------|---------------|----------------|
| Average |     5.412 |              |             |             |             |            |               |                |
| Max     |     8.882 |           16 |          16 |        4096 |        4096 |         64 | relative_bias | torch.bfloat16 |
| Min     |     3.645 |            8 |          16 |         512 |         512 |         64 | causal_mask   | torch.bfloat16 |
| Min     |     0.345 |            1 |          16 |        1024 |        1024 |         64 | pathological  | torch.bfloat16 |

For reference

| Configuration                                 | Forward Time (µ seconds) | Backend          | Speedup |
|-----------------------------------------------|--------------------------|------------------|---------|
| Fastest Config in Sweep (`8 16 4096 4096 64 relative_bias torch.bfloat16`) | 3608                   | Templated Attention                | 1.0  |
| Compiled SDPA (No Mask)                       | 9928                   | Math             | 2.75x   |
| Compiled SDPA (With Mask)                     | 11898                    | Math             | 3.29x   |
| Compiled SDPA (With Mask) | 8704                      | Memory Efficient Attention | 2.42x   |
| Compiled SDPA (No Mask) | 2548                     | FlashAttention2 | 0.706x   |

The speedups are measuring compiled templated attention speed versus different calls to torch.nn.functional.sdpa

<details>

<summary> FULL PERFORMANCE SWEEP NUMBERS </summary>

|   batch_size |   num_heads |   q_seq_len |   k_seq_len |   head_dim | score_mod     | dtype          |   eager_time |   compiled_time |   speedup |
|--------------|-------------|-------------|-------------|------------|---------------|----------------|--------------|-----------------|-----------|
|            1 |          16 |         512 |         512 |         64 | causal_mask   | torch.bfloat16 |      331.444 |          67.221 |     4.931 |
|            1 |          16 |         512 |         512 |         64 | relative_bias | torch.bfloat16 |      335.300 |          64.187 |     5.224 |
|            1 |          16 |         512 |         512 |         64 | head_bias     | torch.bfloat16 |      352.039 |          63.806 |     5.517 |
|            1 |          16 |         512 |         512 |         64 | pathological  | torch.bfloat16 |      371.699 |         711.349 |     0.523 |
|            1 |          16 |        1024 |        1024 |         64 | causal_mask   | torch.bfloat16 |      333.488 |          86.455 |     3.857 |
|            1 |          16 |        1024 |        1024 |         64 | relative_bias | torch.bfloat16 |      322.363 |          82.469 |     3.909 |
|            1 |          16 |        1024 |        1024 |         64 | head_bias     | torch.bfloat16 |      349.967 |          82.233 |     4.256 |
|            1 |          16 |        1024 |        1024 |         64 | pathological  | torch.bfloat16 |      486.359 |        1412.453 |     0.344 |
|            1 |          16 |        4096 |        4096 |         64 | causal_mask   | torch.bfloat16 |     2794.597 |         551.188 |     5.070 |
|            1 |          16 |        4096 |        4096 |         64 | relative_bias | torch.bfloat16 |     3965.150 |         513.101 |     7.728 |
|            1 |          16 |        4096 |        4096 |         64 | head_bias     | torch.bfloat16 |     2408.013 |         504.759 |     4.771 |
|            1 |          16 |        4096 |        4096 |         64 | pathological  | torch.bfloat16 |     6850.531 |       16733.675 |     0.409 |
|            8 |          16 |         512 |         512 |         64 | causal_mask   | torch.bfloat16 |      441.939 |         123.576 |     3.576 |
|            8 |          16 |         512 |         512 |         64 | relative_bias | torch.bfloat16 |      560.379 |         116.710 |     4.801 |
|            8 |          16 |         512 |         512 |         64 | head_bias     | torch.bfloat16 |      421.172 |         115.825 |     3.636 |
|            8 |          16 |         512 |         512 |         64 | pathological  | torch.bfloat16 |      994.492 |        2132.806 |     0.466 |
|            8 |          16 |        1024 |        1024 |         64 | causal_mask   | torch.bfloat16 |     1436.430 |         309.495 |     4.641 |
|            8 |          16 |        1024 |        1024 |         64 | relative_bias | torch.bfloat16 |     1892.216 |         290.186 |     6.521 |
|            8 |          16 |        1024 |        1024 |         64 | head_bias     | torch.bfloat16 |     1360.665 |         282.956 |     4.809 |
|            8 |          16 |        1024 |        1024 |         64 | pathological  | torch.bfloat16 |     3525.532 |        8359.702 |     0.422 |
|            8 |          16 |        4096 |        4096 |         64 | causal_mask   | torch.bfloat16 |    22026.839 |        3864.604 |     5.700 |
|            8 |          16 |        4096 |        4096 |         64 | relative_bias | torch.bfloat16 |    31262.746 |        3609.551 |     8.661 |
|            8 |          16 |        4096 |        4096 |         64 | head_bias     | torch.bfloat16 |    20219.079 |        3480.402 |     5.809 |
|            8 |          16 |        4096 |        4096 |         64 | pathological  | torch.bfloat16 |    54654.647 |      116652.357 |     0.469 |
|           16 |          16 |         512 |         512 |         64 | causal_mask   | torch.bfloat16 |      820.606 |         188.683 |     4.349 |
|           16 |          16 |         512 |         512 |         64 | relative_bias | torch.bfloat16 |     1058.362 |         179.295 |     5.903 |
|           16 |          16 |         512 |         512 |         64 | head_bias     | torch.bfloat16 |      784.372 |         175.714 |     4.464 |
|           16 |          16 |         512 |         512 |         64 | pathological  | torch.bfloat16 |     1890.792 |        4212.877 |     0.449 |
|           16 |          16 |        1024 |        1024 |         64 | causal_mask   | torch.bfloat16 |     2781.830 |         557.017 |     4.994 |
|           16 |          16 |        1024 |        1024 |         64 | relative_bias | torch.bfloat16 |     3694.050 |         525.249 |     7.033 |
|           16 |          16 |        1024 |        1024 |         64 | head_bias     | torch.bfloat16 |     2634.164 |         507.613 |     5.189 |
|           16 |          16 |        1024 |        1024 |         64 | pathological  | torch.bfloat16 |     6959.917 |       15331.116 |     0.454 |
|           16 |          16 |        4096 |        4096 |         64 | causal_mask   | torch.bfloat16 |    43889.096 |        7582.018 |     5.789 |
|           16 |          16 |        4096 |        4096 |         64 | relative_bias | torch.bfloat16 |    62784.293 |        7075.846 |     8.873 |
|           16 |          16 |        4096 |        4096 |         64 | head_bias     | torch.bfloat16 |    40308.606 |        6829.587 |     5.902 |
|           16 |          16 |        4096 |        4096 |         64 | pathological  | torch.bfloat16 |   108892.137 |      233090.953 |     0.467 |
</details>

Pull Request resolved: https://github.com/pytorch/pytorch/pull/121845
Approved by: https://github.com/Chillee, https://github.com/zou3519
2024-04-06 01:10:44 +00:00
drisspg
7fa1be506b Add an option to sdpa benchmark to specify backend (#122368)
# Summary
Adds the ability to specify sdpa backend
Pull Request resolved: https://github.com/pytorch/pytorch/pull/122368
Approved by: https://github.com/cpuhrsch
2024-03-21 07:00:40 +00:00
Eddie Yan
cd380c794f [CUDNN][SDPA] Experimental cuDNN Flash Attention v2 Inference (#115663)
#113713

Going to clean up some of the checks and will remove draft status after.
Can be tested on SM80+ with `TORCH_CUDNN_MHA_ENABLED=1`.

CC @drisspg @ptrblck
Pull Request resolved: https://github.com/pytorch/pytorch/pull/115663
Approved by: https://github.com/drisspg
2024-02-14 22:02:06 +00:00
Aaron Gokaslan
1562dae62c [BE]: Apply RUF025 dict.fromkeys preview rule (#118637)
Simplifies and optimizes dict construction using the `fromkeys` classmethod ctor. This also makes it really obvious when all the keys will have the same static value, which could be a bug if unintentional. It is also significantly faster than using a dict comprehension. The rule is in preview, but I am adding a forward fix for when it becomes stable.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/118637
Approved by: https://github.com/albanD
2024-01-30 20:46:54 +00:00
PyTorch MergeBot
2f84a9d37c Revert "[CUDNN][SDPA] Experimental cuDNN Flash Attention v2 Inference (#115663)"
This reverts commit 5aa92b5090.

Reverted https://github.com/pytorch/pytorch/pull/115663 on behalf of https://github.com/PaliC due to Unfortunately, this pr breaks cuda builds internally ([comment](https://github.com/pytorch/pytorch/pull/115663#issuecomment-1899388813))
2024-01-18 23:40:30 +00:00
Eddie Yan
5aa92b5090 [CUDNN][SDPA] Experimental cuDNN Flash Attention v2 Inference (#115663)
#113713

Going to clean up some of the checks and will remove draft status after.
Can be tested on SM80+ with `TORCH_CUDNN_MHA_ENABLED=1`.

CC @drisspg @ptrblck
Pull Request resolved: https://github.com/pytorch/pytorch/pull/115663
Approved by: https://github.com/drisspg
2024-01-18 01:20:36 +00:00
drisspg
6b120c6cf9 Update the sdpa benchmark to measure forward backward time in isolation (#115986)
# Summary

The benchmarks were getting a little stale and I think it makes more sense to measure in isolation now rather than E2E in a mha component.

This is a pre-req for getting the data for https://github.com/pytorch/pytorch/pull/115357

Output from run:
``` Shell
+------------+-----------+-----------+------------+-----------+-----------+----------------+--------------------+--------------------+
| batch_size | num_heads | q_seq_len | kv_seq_len | embed_dim | is_causal |     dtype      |    forward_time    |   backward_time    |
+------------+-----------+-----------+------------+-----------+-----------+----------------+--------------------+--------------------+
|     1      |    16     |    128    |    128     |   2048    |   True    | torch.bfloat16 | 23.86634959839284  | 66.21150835417211  |
|     1      |    16     |    128    |    128     |   2048    |   False   | torch.bfloat16 | 23.452017060481012 | 66.90612225793302  |
|     1      |    16     |    256    |    256     |   2048    |   True    | torch.bfloat16 | 24.478124547749758 |  76.4232068322599  |
|     1      |    16     |    256    |    256     |   2048    |   False   | torch.bfloat16 |  24.6928428998217  | 75.76151192188263  |
|     1      |    16     |    512    |    512     |   2048    |   True    | torch.bfloat16 | 28.69622849393636  | 114.73898496478796 |
|     1      |    16     |    512    |    512     |   2048    |   False   | torch.bfloat16 | 34.399422979913645 | 112.96746158041059 |
|     1      |    16     |   1024    |    1024    |   2048    |   True    | torch.bfloat16 |  65.4690912924707  | 216.26344555988908 |
|     1      |    16     |   1024    |    1024    |   2048    |   False   | torch.bfloat16 | 88.57532404363155  | 212.07790216431025 |
|     8      |    16     |    128    |    128     |   2048    |   True    | torch.bfloat16 | 11.582905380055308 | 70.09557797573505  |
|     8      |    16     |    128    |    128     |   2048    |   False   | torch.bfloat16 | 12.068384909071026 | 70.01491216942668  |
|     8      |    16     |    256    |    256     |   2048    |   True    | torch.bfloat16 | 31.671419646590945 | 203.54910241439939 |
|     8      |    16     |    256    |    256     |   2048    |   False   | torch.bfloat16 |  33.0585768679157  | 209.45609430782497 |
|     8      |    16     |    512    |    512     |   2048    |   True    | torch.bfloat16 | 87.43969700299202  | 469.8729298543185  |
|     8      |    16     |    512    |    512     |   2048    |   False   | torch.bfloat16 | 123.9265550393611  | 580.1084265112877  |
|     8      |    16     |   1024    |    1024    |   2048    |   True    | torch.bfloat16 | 561.1918237991632  | 1181.655174586922  |
|     8      |    16     |   1024    |    1024    |   2048    |   False   | torch.bfloat16 | 884.2707145959139  | 1662.4679416418073 |
+------------+-----------+-----------+------------+-----------+-----------+----------------+--------------------+--------------------+
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/115986
Approved by: https://github.com/mikaylagawarecki
2023-12-18 22:40:47 +00:00
drisspg
d4c79a3078 Add an attention bias subclass for a lower right causal masking (#114823)
# Summary
This PR introduces a new Tensor subclass that is designed to be used with torch.nn.functional.scaled_dot_product_attention. Currently we have a boolean `is_causal` flag that allows users to do do causal masking without the need to actually create the "realized" attention bias and pass into sdpa. We originally added this flag since there is native support in both fused kernels we support. This provides a big performance gain ( the kernels only need to iterate over ~0.5x the sequence, and for very large sequence lengths this can provide vary large memory improvements.

The flag was introduced when the early on in the kernel development and at the time it was implicitly meant to "upper_left" causal attention. This distinction only matters when the attention_bias is not square. For a more detailed break down see: https://github.com/pytorch/pytorch/issues/108108. The kernels default behavior has since changed, largely due to the rise of autogressive text generation. And unfortunately this would lead to a BC break. In the long term it may actually be beneficial to change the default meaning of `is_causal` to represent lower_right causal masking.

The larger theme though is laid here: https://github.com/pytorch/pytorch/issues/110681. The thesis being that there is alot of innovation in SDPA revolving around the attention_bias being used. This is the first in hopefully a few more attention_biases that we would like to add. The next interesting one would be `sliding_window` which is used by the popular mistral model family.

Results from benchmarking, I improved the meff_attention perf hence the slightly decreased max perf.
```Shell
+---------+--------------------+------------+-----------+-----------+-----------+-----------+----------------+----------+
|  Type   |      Speedup       | batch_size | num_heads | q_seq_len | k_seq_len | embed_dim |     dtype      | head_dim |
+---------+--------------------+------------+-----------+-----------+-----------+-----------+----------------+----------+
| Average | 1.2388050062214226 |            |           |           |           |           |                |          |
|   Max   | 1.831672915579016  |    128     |    32     |   1024    |   2048    |   2048    | torch.bfloat16 |    64    |
|   Min   | 0.9430534166730135 |     1      |    16     |    256    |    416    |   2048    | torch.bfloat16 |   128    |
+---------+--------------------+------------+-----------+-----------+-----------+-----------+----------------+----------+
```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/114823
Approved by: https://github.com/cpuhrsch
2023-12-06 08:29:26 +00:00