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Include sm_110 in Blackwell-family arch gating (follow-up to #2572) #2590

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Merged
jayhshah merged 3 commits into from
May 26, 2026
+7 −9
Merged

Include sm_110 in Blackwell-family arch gating (follow-up to #2572) #2590

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ecf2a26
Fix bwd postprocess 2CTA gating to include sm_11x
Johnsonms May 25, 2026
5592f24
Include sm_110 in interface.py Blackwell-family heuristics
Johnsonms May 25, 2026
77efc89
Apply ruff format to flash_bwd_sm100.py
Johnsonms May 25, 2026
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4 changes: 2 additions & 2 deletions flash_attn/cute/flash_bwd_postprocess.py
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Original file line number Diff line number Diff line change
Expand Up @@ -63,7 +63,7 @@ def __init__(
self.num_threads = num_threads
self.AtomLayoutMdQ = AtomLayoutMdQ
self.dQ_swapAB = dQ_swapAB
self.use_2cta_instrs = use_2cta_instrs and arch // 10 == 10 and head_dim != 64
self.use_2cta_instrs = use_2cta_instrs and arch // 10 in [10, 11] and head_dim != 64
self.cluster_size = cluster_size

@staticmethod
Expand Down Expand Up @@ -373,7 +373,7 @@ def kernel(
seqlen_q = seqlen.seqlen_q
seqlen_q_rounded = cute.round_up(seqlen_q, self.tile_m)

if const_expr(self.arch // 10 == 10 and self.use_2cta_instrs):
if const_expr(self.arch // 10 in [10, 11] and self.use_2cta_instrs):
# 2-CTA: remap dQaccum layout into TMEM view before writing sdQ
num_reduce_threads = self.num_threads
thr_mma_dsk = tiled_mma.get_slice(tidx)
Expand Down
4 changes: 1 addition & 3 deletions flash_attn/cute/flash_bwd_sm100.py
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Original file line number Diff line number Diff line change
Expand Up @@ -1423,9 +1423,7 @@ def kernel(
)
TileSchedulerCls = partial(self.tile_scheduler_cls.create, tile_sched_params)

AttentionMaskCls = self._generate_attention_mask_cls(
window_size_left, window_size_right
)
AttentionMaskCls = self._generate_attention_mask_cls(window_size_left, window_size_right)
# EMPTY
# (15)
if warp_idx == self.empty_warp_id:
Expand Down
8 changes: 4 additions & 4 deletions flash_attn/cute/interface.py
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Original file line number Diff line number Diff line change
Expand Up @@ -530,7 +530,7 @@ def _flash_attn_fwd(
if cu_seqlens_k is None and seqused_k is None:
min_seqlen_k = seqlen_k
seqlen_q_packgqa = max_seqlen_q * qhead_per_kvhead
if arch // 10 == 10:
if arch // 10 in [10, 11]:
q_stage = 2 if seqlen_q_packgqa > tile_m else 1
else:
q_stage = 1
Expand Down Expand Up @@ -575,8 +575,8 @@ def _flash_attn_fwd(
and (tile_m % qhead_per_kvhead == 0 or not pack_gqa)
)

# hd=256 2CTA forward uses dedicated kernel (SM100 only)
use_dedicated_hd256_kernel = arch // 10 == 10 and head_dim == 256 and head_dim_v == 256
# hd=256 2CTA forward uses dedicated kernel (Blackwell family)
use_dedicated_hd256_kernel = arch // 10 in [10, 11] and head_dim == 256 and head_dim_v == 256
use_2cta_instrs = use_2cta_instrs or use_dedicated_hd256_kernel

if softcap is not None:
Expand Down Expand Up @@ -1332,7 +1332,7 @@ def _flash_attn_bwd(
cluster_size = 2 if head_dim >= 128 and not disable_2cta else 1
use_2cta_instrs = cluster_size==2

use_dedicated_hd256_kernel = arch // 10 == 10 and head_dim == 256 and head_dim_v == 256
use_dedicated_hd256_kernel = arch // 10 in [10, 11] and head_dim == 256 and head_dim_v == 256
use_2cta_instrs = use_2cta_instrs or use_dedicated_hd256_kernel

q, k, v, out, dout, lse, cu_seqlens_q, cu_seqlens_k, seqused_q, seqused_k = [
Expand Down
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