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[CK_TILE][FMHA] Extend pipelines with pssk for gfx11/12#4957

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illsilin merged 2 commits intodevelopfrom
users/ex-rzr/ck/fmha-extend-pipelines-for-gfx11-12
Mar 4, 2026
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[CK_TILE][FMHA] Extend pipelines with pssk for gfx11/12#4957
illsilin merged 2 commits intodevelopfrom
users/ex-rzr/ck/fmha-extend-pipelines-for-gfx11-12

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@ex-rzr ex-rzr commented Feb 27, 2026

Motivation

Build pipelines with seqlen padding only to support vectorized loads in the hdim dimension.
The existing pipelines have either all dims padded or all dims not padded.
These pipelines can be used in ComfyUI for slightly better performance.

Technical Details

Also a fix included for correct FLOPS calculation in tile_example_fmha_fwd when seqlen_q * seqlen_k overflows index_t capacity (signed int32).

Test Plan

The existing test cases will use the new pipelines when parameters allow (seqlens - padded, hdims - not padded):

ninja test_ck_tile_fmha_fwd

bin/test_ck_tile_fmha_fwd_fp16
bin/test_ck_tile_fmha_fwd_bf16

bin/test_ck_tile_fmha_fwd_fp8bf16 # for gfx12

Test Result

All tests must pass.

Submission Checklist

@ex-rzr ex-rzr changed the title xtend pipelines for gfx11/12 [CK_TILE][FMHA] Extend pipelines with pssk for gfx11/12 Feb 27, 2026
@ex-rzr ex-rzr self-assigned this Feb 27, 2026
@ex-rzr ex-rzr added the organization: streamhpc contributors from streamhpc label Feb 27, 2026
@ex-rzr ex-rzr marked this pull request as ready for review February 27, 2026 13:36
@ex-rzr ex-rzr requested a review from a team as a code owner February 27, 2026 13:36
@illsilin illsilin merged commit d2e4eb8 into develop Mar 4, 2026
46 checks passed
@illsilin illsilin deleted the users/ex-rzr/ck/fmha-extend-pipelines-for-gfx11-12 branch March 4, 2026 04:50
assistant-librarian bot pushed a commit to ROCm/composable_kernel that referenced this pull request Mar 4, 2026
[CK_TILE][FMHA] Extend pipelines with pssk for gfx11/12
 (#4957)

## Motivation

Build pipelines with seqlen padding only to support vectorized loads in
the hdim dimension.
The existing pipelines have either all dims padded or all dims not
padded.
These pipelines can be used in ComfyUI for slightly better performance.

## Technical Details

Also a fix included for correct FLOPS calculation in
`tile_example_fmha_fwd` when `seqlen_q * seqlen_k` overflows index_t
capacity (signed int32).

## Test Plan

The existing test cases will use the new pipelines when parameters allow
(seqlens - padded, hdims - not padded):
```
ninja test_ck_tile_fmha_fwd

bin/test_ck_tile_fmha_fwd_fp16
bin/test_ck_tile_fmha_fwd_bf16

bin/test_ck_tile_fmha_fwd_fp8bf16 # for gfx12
```

## Test Result

All tests must pass.

## Submission Checklist

- [x] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
NaveenElumalaiAMD pushed a commit that referenced this pull request Mar 6, 2026
## Motivation

Build pipelines with seqlen padding only to support vectorized loads in
the hdim dimension.
The existing pipelines have either all dims padded or all dims not
padded.
These pipelines can be used in ComfyUI for slightly better performance.

## Technical Details

Also a fix included for correct FLOPS calculation in
`tile_example_fmha_fwd` when `seqlen_q * seqlen_k` overflows index_t
capacity (signed int32).

## Test Plan

The existing test cases will use the new pipelines when parameters allow
(seqlens - padded, hdims - not padded):
```
ninja test_ck_tile_fmha_fwd

bin/test_ck_tile_fmha_fwd_fp16
bin/test_ck_tile_fmha_fwd_bf16

bin/test_ck_tile_fmha_fwd_fp8bf16 # for gfx12
```

## Test Result

All tests must pass.

## Submission Checklist

- [x] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
illsilin pushed a commit that referenced this pull request Mar 10, 2026
## Motivation
Tune gfx11 FMHA codegen to recover performance for mainly PSSK (padded
seqlen_q/k) cases.
This tuning is based on heuristic search and improves performance in
most tested shapes.
Performance should be evaluated on top of
[`#5018`](#5018)
(required baseline).

## Technical Details

  - Updated gfx11 codegen heuristic choices for tile size and occupancy.
   - Updated gfx11 pipeline selection:
- Disabled the `npad` (`f,f,f,f`) qr entry because it was consistently
slower than the `pssk` (`t,t,f,f`) path, and kept `pssk` enabled so npad
cases are dispatched to the faster kernel path.`
- Kept gfx12 unchanged: with PSSK support from
[`#4957`](#4957),
existing gfx12 config is already sufficient.
  - Tuning rationale:
    - In some cases, higher `kBlockPerCu` lowers register pressure.
- On RDNA, this generally aligns with better performance when
`waves_per_eu >= 6`.

## Test Plan
- test_ck_tile_fmha
- tile_example_fmha_fwd: tested this on gfx1100 and gfx1151
./build/bin/tile_example_fmha_fwd -prec=bf16 -mode={0/1} -b=1 -h=24
-d=128 -s={seqlen} -s_k={seqlen} -lse=0 -iperm={0/1} -operm={0/1}

## Test Result
- TFLOPs by sequence length target: `gfx1100` layout: `bhsd`
- mode: batch / VGPR usage: 225 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 74.10 | 71.97 | 0.97x
4096 | 66.26 | 77.79 | 1.17x
8192 | 68.18 | 75.88 | 1.11x
12288 | 68.47 | 80.44 | 1.17x
16384 | 59.54 | 79.66 | 1.34x
20480 | 55.78 | 77.91 | 1.40x
24576 | 55.08 | 77.47 | 1.41x
27280 | 47.45 | 77.16 | 1.63x
- mode: group / VGPR usage: 256 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 71.47 | 70.6 | 0.99x
4096 | 64.74 | 77.06 | 1.19x
8192 | 64.68 | 75.47 | 1.17x
12288 | 66.43 | 79.95 | 1.20x
16384 | 56.02 | 79.73 | 1.42x
20480 | 50.21 | 78.15 | 1.56x
24576 | 47.29 | 77.53 | 1.64x
27280 | 46.13 | 77.04 | 1.67x

- TFLOPs by sequence length target: `gfx1151` layout: `bshd`
- mode: batch / VGPR usage: 225 vs 223

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 26.85 | 29.17 | 1.09x
4096 | 24.75 | 26.01 | 1.05x
8192 | 25.24 | 25.50 | 1.01x
12288 | 25.18 | 25.00 | 0.99x
16384 | 24.79 | 25.91 | 1.05x
20480 | 25.56 | 25.24 | 0.99x
24576 | 25.13 | 26.20 | 1.04x
27280 | 10.78 | 26.35 | 2.44x
- mode: group / VGPR usage: 256 vs 229

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 27.44 | 26.71 | 0.97x
4096 | 21.89 | 23.09 | 1.05x
8192 | 22.85 | 24.49 | 1.07x
12288 | 24.33 | 24.42 | 1.00x
16384 | 20.05 | 24.98 | 1.24x
20480 | 14.70 | 25.15 | 1.71x
24576 | 11.30 | 26.31 | 2.33x
27280 | 10.10 | 26.32 | 2.61x


## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
assistant-librarian bot pushed a commit to ROCm/composable_kernel that referenced this pull request Mar 10, 2026
[CK_TILE] Update gfx11 FMHA forward kernel configs

## Motivation
Tune gfx11 FMHA codegen to recover performance for mainly PSSK (padded
seqlen_q/k) cases.
This tuning is based on heuristic search and improves performance in
most tested shapes.
Performance should be evaluated on top of
[`ROCm/rocm-libraries#5018`](ROCm/rocm-libraries#5018)
(required baseline).

## Technical Details

  - Updated gfx11 codegen heuristic choices for tile size and occupancy.
   - Updated gfx11 pipeline selection:
- Disabled the `npad` (`f,f,f,f`) qr entry because it was consistently
slower than the `pssk` (`t,t,f,f`) path, and kept `pssk` enabled so npad
cases are dispatched to the faster kernel path.`
- Kept gfx12 unchanged: with PSSK support from
[`ROCm/rocm-libraries#4957`](ROCm/rocm-libraries#4957),
existing gfx12 config is already sufficient.
  - Tuning rationale:
    - In some cases, higher `kBlockPerCu` lowers register pressure.
- On RDNA, this generally aligns with better performance when
`waves_per_eu >= 6`.

## Test Plan
- test_ck_tile_fmha
- tile_example_fmha_fwd: tested this on gfx1100 and gfx1151
./build/bin/tile_example_fmha_fwd -prec=bf16 -mode={0/1} -b=1 -h=24
-d=128 -s={seqlen} -s_k={seqlen} -lse=0 -iperm={0/1} -operm={0/1}

## Test Result
- TFLOPs by sequence length target: `gfx1100` layout: `bhsd`
- mode: batch / VGPR usage: 225 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 74.10 | 71.97 | 0.97x
4096 | 66.26 | 77.79 | 1.17x
8192 | 68.18 | 75.88 | 1.11x
12288 | 68.47 | 80.44 | 1.17x
16384 | 59.54 | 79.66 | 1.34x
20480 | 55.78 | 77.91 | 1.40x
24576 | 55.08 | 77.47 | 1.41x
27280 | 47.45 | 77.16 | 1.63x
- mode: group / VGPR usage: 256 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 71.47 | 70.6 | 0.99x
4096 | 64.74 | 77.06 | 1.19x
8192 | 64.68 | 75.47 | 1.17x
12288 | 66.43 | 79.95 | 1.20x
16384 | 56.02 | 79.73 | 1.42x
20480 | 50.21 | 78.15 | 1.56x
24576 | 47.29 | 77.53 | 1.64x
27280 | 46.13 | 77.04 | 1.67x

- TFLOPs by sequence length target: `gfx1151` layout: `bshd`
- mode: batch / VGPR usage: 225 vs 223

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 26.85 | 29.17 | 1.09x
4096 | 24.75 | 26.01 | 1.05x
8192 | 25.24 | 25.50 | 1.01x
12288 | 25.18 | 25.00 | 0.99x
16384 | 24.79 | 25.91 | 1.05x
20480 | 25.56 | 25.24 | 0.99x
24576 | 25.13 | 26.20 | 1.04x
27280 | 10.78 | 26.35 | 2.44x
- mode: group / VGPR usage: 256 vs 229

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 27.44 | 26.71 | 0.97x
4096 | 21.89 | 23.09 | 1.05x
8192 | 22.85 | 24.49 | 1.07x
12288 | 24.33 | 24.42 | 1.00x
16384 | 20.05 | 24.98 | 1.24x
20480 | 14.70 | 25.15 | 1.71x
24576 | 11.30 | 26.31 | 2.33x
27280 | 10.10 | 26.32 | 2.61x

## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
kokolchin pushed a commit to kokolchin/rocm-libraries that referenced this pull request Mar 11, 2026
## Motivation
Tune gfx11 FMHA codegen to recover performance for mainly PSSK (padded
seqlen_q/k) cases.
This tuning is based on heuristic search and improves performance in
most tested shapes.
Performance should be evaluated on top of
[`ROCm#5018`](ROCm#5018)
(required baseline).

## Technical Details

  - Updated gfx11 codegen heuristic choices for tile size and occupancy.
   - Updated gfx11 pipeline selection:
- Disabled the `npad` (`f,f,f,f`) qr entry because it was consistently
slower than the `pssk` (`t,t,f,f`) path, and kept `pssk` enabled so npad
cases are dispatched to the faster kernel path.`
- Kept gfx12 unchanged: with PSSK support from
[`ROCm#4957`](ROCm#4957),
existing gfx12 config is already sufficient.
  - Tuning rationale:
    - In some cases, higher `kBlockPerCu` lowers register pressure.
- On RDNA, this generally aligns with better performance when
`waves_per_eu >= 6`.

## Test Plan
- test_ck_tile_fmha
- tile_example_fmha_fwd: tested this on gfx1100 and gfx1151
./build/bin/tile_example_fmha_fwd -prec=bf16 -mode={0/1} -b=1 -h=24
-d=128 -s={seqlen} -s_k={seqlen} -lse=0 -iperm={0/1} -operm={0/1}

## Test Result
- TFLOPs by sequence length target: `gfx1100` layout: `bhsd`
- mode: batch / VGPR usage: 225 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 74.10 | 71.97 | 0.97x
4096 | 66.26 | 77.79 | 1.17x
8192 | 68.18 | 75.88 | 1.11x
12288 | 68.47 | 80.44 | 1.17x
16384 | 59.54 | 79.66 | 1.34x
20480 | 55.78 | 77.91 | 1.40x
24576 | 55.08 | 77.47 | 1.41x
27280 | 47.45 | 77.16 | 1.63x
- mode: group / VGPR usage: 256 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 71.47 | 70.6 | 0.99x
4096 | 64.74 | 77.06 | 1.19x
8192 | 64.68 | 75.47 | 1.17x
12288 | 66.43 | 79.95 | 1.20x
16384 | 56.02 | 79.73 | 1.42x
20480 | 50.21 | 78.15 | 1.56x
24576 | 47.29 | 77.53 | 1.64x
27280 | 46.13 | 77.04 | 1.67x

- TFLOPs by sequence length target: `gfx1151` layout: `bshd`
- mode: batch / VGPR usage: 225 vs 223

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 26.85 | 29.17 | 1.09x
4096 | 24.75 | 26.01 | 1.05x
8192 | 25.24 | 25.50 | 1.01x
12288 | 25.18 | 25.00 | 0.99x
16384 | 24.79 | 25.91 | 1.05x
20480 | 25.56 | 25.24 | 0.99x
24576 | 25.13 | 26.20 | 1.04x
27280 | 10.78 | 26.35 | 2.44x
- mode: group / VGPR usage: 256 vs 229

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 27.44 | 26.71 | 0.97x
4096 | 21.89 | 23.09 | 1.05x
8192 | 22.85 | 24.49 | 1.07x
12288 | 24.33 | 24.42 | 1.00x
16384 | 20.05 | 24.98 | 1.24x
20480 | 14.70 | 25.15 | 1.71x
24576 | 11.30 | 26.31 | 2.33x
27280 | 10.10 | 26.32 | 2.61x


## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
jovanau pushed a commit to jovanau/rocm-libraries that referenced this pull request Mar 19, 2026
## Motivation

Build pipelines with seqlen padding only to support vectorized loads in
the hdim dimension.
The existing pipelines have either all dims padded or all dims not
padded.
These pipelines can be used in ComfyUI for slightly better performance.

## Technical Details

Also a fix included for correct FLOPS calculation in
`tile_example_fmha_fwd` when `seqlen_q * seqlen_k` overflows index_t
capacity (signed int32).

## Test Plan

The existing test cases will use the new pipelines when parameters allow
(seqlens - padded, hdims - not padded):
```
ninja test_ck_tile_fmha_fwd

bin/test_ck_tile_fmha_fwd_fp16
bin/test_ck_tile_fmha_fwd_bf16

bin/test_ck_tile_fmha_fwd_fp8bf16 # for gfx12
```

## Test Result

All tests must pass.

## Submission Checklist

- [x] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
jovanau pushed a commit to jovanau/rocm-libraries that referenced this pull request Mar 19, 2026
## Motivation
Tune gfx11 FMHA codegen to recover performance for mainly PSSK (padded
seqlen_q/k) cases.
This tuning is based on heuristic search and improves performance in
most tested shapes.
Performance should be evaluated on top of
[`ROCm#5018`](ROCm#5018)
(required baseline).

## Technical Details

  - Updated gfx11 codegen heuristic choices for tile size and occupancy.
   - Updated gfx11 pipeline selection:
- Disabled the `npad` (`f,f,f,f`) qr entry because it was consistently
slower than the `pssk` (`t,t,f,f`) path, and kept `pssk` enabled so npad
cases are dispatched to the faster kernel path.`
- Kept gfx12 unchanged: with PSSK support from
[`ROCm#4957`](ROCm#4957),
existing gfx12 config is already sufficient.
  - Tuning rationale:
    - In some cases, higher `kBlockPerCu` lowers register pressure.
- On RDNA, this generally aligns with better performance when
`waves_per_eu >= 6`.

## Test Plan
- test_ck_tile_fmha
- tile_example_fmha_fwd: tested this on gfx1100 and gfx1151
./build/bin/tile_example_fmha_fwd -prec=bf16 -mode={0/1} -b=1 -h=24
-d=128 -s={seqlen} -s_k={seqlen} -lse=0 -iperm={0/1} -operm={0/1}

## Test Result
- TFLOPs by sequence length target: `gfx1100` layout: `bhsd`
- mode: batch / VGPR usage: 225 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 74.10 | 71.97 | 0.97x
4096 | 66.26 | 77.79 | 1.17x
8192 | 68.18 | 75.88 | 1.11x
12288 | 68.47 | 80.44 | 1.17x
16384 | 59.54 | 79.66 | 1.34x
20480 | 55.78 | 77.91 | 1.40x
24576 | 55.08 | 77.47 | 1.41x
27280 | 47.45 | 77.16 | 1.63x
- mode: group / VGPR usage: 256 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 71.47 | 70.6 | 0.99x
4096 | 64.74 | 77.06 | 1.19x
8192 | 64.68 | 75.47 | 1.17x
12288 | 66.43 | 79.95 | 1.20x
16384 | 56.02 | 79.73 | 1.42x
20480 | 50.21 | 78.15 | 1.56x
24576 | 47.29 | 77.53 | 1.64x
27280 | 46.13 | 77.04 | 1.67x

- TFLOPs by sequence length target: `gfx1151` layout: `bshd`
- mode: batch / VGPR usage: 225 vs 223

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 26.85 | 29.17 | 1.09x
4096 | 24.75 | 26.01 | 1.05x
8192 | 25.24 | 25.50 | 1.01x
12288 | 25.18 | 25.00 | 0.99x
16384 | 24.79 | 25.91 | 1.05x
20480 | 25.56 | 25.24 | 0.99x
24576 | 25.13 | 26.20 | 1.04x
27280 | 10.78 | 26.35 | 2.44x
- mode: group / VGPR usage: 256 vs 229

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 27.44 | 26.71 | 0.97x
4096 | 21.89 | 23.09 | 1.05x
8192 | 22.85 | 24.49 | 1.07x
12288 | 24.33 | 24.42 | 1.00x
16384 | 20.05 | 24.98 | 1.24x
20480 | 14.70 | 25.15 | 1.71x
24576 | 11.30 | 26.31 | 2.33x
27280 | 10.10 | 26.32 | 2.61x


## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
johannes-graner pushed a commit that referenced this pull request Mar 20, 2026
## Motivation

Build pipelines with seqlen padding only to support vectorized loads in
the hdim dimension.
The existing pipelines have either all dims padded or all dims not
padded.
These pipelines can be used in ComfyUI for slightly better performance.

## Technical Details

Also a fix included for correct FLOPS calculation in
`tile_example_fmha_fwd` when `seqlen_q * seqlen_k` overflows index_t
capacity (signed int32).

## Test Plan

The existing test cases will use the new pipelines when parameters allow
(seqlens - padded, hdims - not padded):
```
ninja test_ck_tile_fmha_fwd

bin/test_ck_tile_fmha_fwd_fp16
bin/test_ck_tile_fmha_fwd_bf16

bin/test_ck_tile_fmha_fwd_fp8bf16 # for gfx12
```

## Test Result

All tests must pass.

## Submission Checklist

- [x] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
johannes-graner pushed a commit that referenced this pull request Mar 20, 2026
## Motivation
Tune gfx11 FMHA codegen to recover performance for mainly PSSK (padded
seqlen_q/k) cases.
This tuning is based on heuristic search and improves performance in
most tested shapes.
Performance should be evaluated on top of
[`#5018`](#5018)
(required baseline).

## Technical Details

  - Updated gfx11 codegen heuristic choices for tile size and occupancy.
   - Updated gfx11 pipeline selection:
- Disabled the `npad` (`f,f,f,f`) qr entry because it was consistently
slower than the `pssk` (`t,t,f,f`) path, and kept `pssk` enabled so npad
cases are dispatched to the faster kernel path.`
- Kept gfx12 unchanged: with PSSK support from
[`#4957`](#4957),
existing gfx12 config is already sufficient.
  - Tuning rationale:
    - In some cases, higher `kBlockPerCu` lowers register pressure.
- On RDNA, this generally aligns with better performance when
`waves_per_eu >= 6`.

## Test Plan
- test_ck_tile_fmha
- tile_example_fmha_fwd: tested this on gfx1100 and gfx1151
./build/bin/tile_example_fmha_fwd -prec=bf16 -mode={0/1} -b=1 -h=24
-d=128 -s={seqlen} -s_k={seqlen} -lse=0 -iperm={0/1} -operm={0/1}

## Test Result
- TFLOPs by sequence length target: `gfx1100` layout: `bhsd`
- mode: batch / VGPR usage: 225 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 74.10 | 71.97 | 0.97x
4096 | 66.26 | 77.79 | 1.17x
8192 | 68.18 | 75.88 | 1.11x
12288 | 68.47 | 80.44 | 1.17x
16384 | 59.54 | 79.66 | 1.34x
20480 | 55.78 | 77.91 | 1.40x
24576 | 55.08 | 77.47 | 1.41x
27280 | 47.45 | 77.16 | 1.63x
- mode: group / VGPR usage: 256 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 71.47 | 70.6 | 0.99x
4096 | 64.74 | 77.06 | 1.19x
8192 | 64.68 | 75.47 | 1.17x
12288 | 66.43 | 79.95 | 1.20x
16384 | 56.02 | 79.73 | 1.42x
20480 | 50.21 | 78.15 | 1.56x
24576 | 47.29 | 77.53 | 1.64x
27280 | 46.13 | 77.04 | 1.67x

- TFLOPs by sequence length target: `gfx1151` layout: `bshd`
- mode: batch / VGPR usage: 225 vs 223

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 26.85 | 29.17 | 1.09x
4096 | 24.75 | 26.01 | 1.05x
8192 | 25.24 | 25.50 | 1.01x
12288 | 25.18 | 25.00 | 0.99x
16384 | 24.79 | 25.91 | 1.05x
20480 | 25.56 | 25.24 | 0.99x
24576 | 25.13 | 26.20 | 1.04x
27280 | 10.78 | 26.35 | 2.44x
- mode: group / VGPR usage: 256 vs 229

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 27.44 | 26.71 | 0.97x
4096 | 21.89 | 23.09 | 1.05x
8192 | 22.85 | 24.49 | 1.07x
12288 | 24.33 | 24.42 | 1.00x
16384 | 20.05 | 24.98 | 1.24x
20480 | 14.70 | 25.15 | 1.71x
24576 | 11.30 | 26.31 | 2.33x
27280 | 10.10 | 26.32 | 2.61x


## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
hyoon1 added a commit to hyoon1/composable_kernel that referenced this pull request Mar 29, 2026
## Motivation
Tune gfx11 FMHA codegen to recover performance for mainly PSSK (padded
seqlen_q/k) cases.
This tuning is based on heuristic search and improves performance in
most tested shapes.
Performance should be evaluated on top of
[`ROCm/rocm-libraries#5018`](ROCm/rocm-libraries#5018)
(required baseline).

## Technical Details

  - Updated gfx11 codegen heuristic choices for tile size and occupancy.
   - Updated gfx11 pipeline selection:
- Disabled the `npad` (`f,f,f,f`) qr entry because it was consistently
slower than the `pssk` (`t,t,f,f`) path, and kept `pssk` enabled so npad
cases are dispatched to the faster kernel path.`
- Kept gfx12 unchanged: with PSSK support from
[`ROCm/rocm-libraries#4957`](ROCm/rocm-libraries#4957),
existing gfx12 config is already sufficient.
  - Tuning rationale:
    - In some cases, higher `kBlockPerCu` lowers register pressure.
- On RDNA, this generally aligns with better performance when
`waves_per_eu >= 6`.

## Test Plan
- test_ck_tile_fmha
- tile_example_fmha_fwd: tested this on gfx1100 and gfx1151
./build/bin/tile_example_fmha_fwd -prec=bf16 -mode={0/1} -b=1 -h=24
-d=128 -s={seqlen} -s_k={seqlen} -lse=0 -iperm={0/1} -operm={0/1}

## Test Result
- TFLOPs by sequence length target: `gfx1100` layout: `bhsd`
- mode: batch / VGPR usage: 225 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 74.10 | 71.97 | 0.97x
4096 | 66.26 | 77.79 | 1.17x
8192 | 68.18 | 75.88 | 1.11x
12288 | 68.47 | 80.44 | 1.17x
16384 | 59.54 | 79.66 | 1.34x
20480 | 55.78 | 77.91 | 1.40x
24576 | 55.08 | 77.47 | 1.41x
27280 | 47.45 | 77.16 | 1.63x
- mode: group / VGPR usage: 256 vs 214

SeqLen | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 71.47 | 70.6 | 0.99x
4096 | 64.74 | 77.06 | 1.19x
8192 | 64.68 | 75.47 | 1.17x
12288 | 66.43 | 79.95 | 1.20x
16384 | 56.02 | 79.73 | 1.42x
20480 | 50.21 | 78.15 | 1.56x
24576 | 47.29 | 77.53 | 1.64x
27280 | 46.13 | 77.04 | 1.67x

- TFLOPs by sequence length target: `gfx1151` layout: `bshd`
- mode: batch / VGPR usage: 225 vs 223

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 26.85 | 29.17 | 1.09x
4096 | 24.75 | 26.01 | 1.05x
8192 | 25.24 | 25.50 | 1.01x
12288 | 25.18 | 25.00 | 0.99x
16384 | 24.79 | 25.91 | 1.05x
20480 | 25.56 | 25.24 | 0.99x
24576 | 25.13 | 26.20 | 1.04x
27280 | 10.78 | 26.35 | 2.44x
- mode: group / VGPR usage: 256 vs 229

Batch | Baseline | Tuned | Gain
-- | -- | -- | --
1024 | 27.44 | 26.71 | 0.97x
4096 | 21.89 | 23.09 | 1.05x
8192 | 22.85 | 24.49 | 1.07x
12288 | 24.33 | 24.42 | 1.00x
16384 | 20.05 | 24.98 | 1.24x
20480 | 14.70 | 25.15 | 1.71x
24576 | 11.30 | 26.31 | 2.33x
27280 | 10.10 | 26.32 | 2.61x


## Submission Checklist

- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
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