D1: Add K sub-tile loop for hd=512 (const_expr guarded, hd≤256 path unchanged)

This commit is contained in:
2026-05-24 04:51:51 +00:00
parent 9ed927f86a
commit 8f0c9e0dad

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@@ -181,7 +181,6 @@ class FmhaKernel:
tBsK,tBgK = cpasync.tma_partition(tma_k,0,b_lay,cute.group_modes(sK,0,3),cute.group_modes(tCgK,0,3))
tVsV,tVgV = cpasync.tma_partition(tma_v,0,b_lay,cute.group_modes(sV,0,3),cute.group_modes(tCgV,0,3))
tAgQ = tAgQ[(None,0,None,0)]; tBgK = tBgK[(None,0,None,0)]; tVgV = tVgV[(None,0,None,0)]
print(f"TMA: tAgQ shape={cute.shape(tAgQ)}, tBgK shape={cute.shape(tBgK)}, tVgV shape={cute.shape(tVgV)}")
tCrQ = qk_mma.make_fragment_A(sQ); tCrK = qk_mma.make_fragment_B(sK)
tCrV = pv_mma.make_fragment_B(sV)
@@ -213,50 +212,104 @@ class FmhaKernel:
# ===== TMA LOAD warp =====
if warp_idx == self.tma_warp_id:
qp.reset(); qh = qp.acquire_and_advance()
cute.copy(tma_q, tAgQ[(None, Int32(0))], tAsQ[(None, qh.index)], tma_bar_ptr=qh.barrier)
qp.tail()
kvp.reset(); pk = kvp.try_acquire()
for kt in cutlass.range(0, self.n_kv_tiles, 1, unroll=1):
kvh = kvp.acquire_and_advance(pk)
cute.copy(tma_k, tBgK[(None, kt)], tBsK[(None, kvh.index)], tma_bar_ptr=kvh.barrier)
cute.copy(tma_v, tVgV[(None, kt)], tVsV[(None, kvh.index)], tma_bar_ptr=kvh.barrier)
pk = cutlass.Boolean(1)
kvp.tail()
if const_expr(self.n_k_sub_tiles > 1):
# K sub-tiling path (hd=512): serialized TMA loads with barrier sync
_ksub_bar = pipeline.NamedBarrier(barrier_id=6, num_threads=64) # TMA + MMA warps
_v_bar = pipeline.NamedBarrier(barrier_id=7, num_threads=64) # TMA + MMA warps
for kt in range(self.n_kv_tiles):
for k_sub in range(self.n_k_sub_tiles):
# Load Q[k_sub] → sQ
cute.copy(tma_q, tAgQ[(None, Int32(k_sub))], tAsQ[(None, 0)])
# Load K[k_sub] → sK
cute.copy(tma_k, tBgK[(None, Int32(k_sub))], tBsK[(None, 0)])
cute.arch.cp_async_bulk_commit_group()
cute.arch.cp_async_bulk_wait_group(0, read=True)
# Sync with MMA warp: sQ and sK ready
_ksub_bar.arrive_and_wait()
# Load V[kt] → sV
cute.copy(tma_v, tVgV[(None, Int32(kt))], tVsV[(None, 0)])
cute.arch.cp_async_bulk_commit_group()
cute.arch.cp_async_bulk_wait_group(0, read=True)
# Sync with MMA warp: sV ready for PV
_v_bar.arrive_and_wait()
else:
# Original pipeline path (hd≤256)
qp.reset(); qh = qp.acquire_and_advance()
cute.copy(tma_q, tAgQ[(None, Int32(0))], tAsQ[(None, qh.index)], tma_bar_ptr=qh.barrier)
qp.tail()
kvp.reset(); pk = kvp.try_acquire()
for kt in cutlass.range(0, self.n_kv_tiles, 1, unroll=1):
kvh = kvp.acquire_and_advance(pk)
cute.copy(tma_k, tBgK[(None, kt)], tBsK[(None, kvh.index)], tma_bar_ptr=kvh.barrier)
cute.copy(tma_v, tVgV[(None, kt)], tVsV[(None, kvh.index)], tma_bar_ptr=kvh.barrier)
pk = cutlass.Boolean(1)
kvp.tail()
# ===== MMA warp =====
if warp_idx == self.mma_warp_id:
tmem.wait_for_alloc()
qc.reset(); qh = qc.wait_and_advance(); qh.release()
kvc.reset(); pk = kvc.try_wait()
acc_st = pipeline.make_pipeline_state(pipeline.PipelineUserType.Producer, self.num_acc_stage)
acc_pipe.producer_acquire(acc_st)
for kt in range(self.n_kv_tiles):
kvh = kvc.wait_and_advance(pk); pk = cutlass.Boolean(1)
sh = s_prod.acquire_and_advance()
qk_mma.set(tcgen05.Field.ACCUMULATE, False)
for kb in cutlass.range(cute.size(tCrQ, mode=[2]), unroll_full=True):
cute.gemm(qk_mma, tStS0, tCrQ[(None,None,kb,0)], tCrK[(None,None,kb,kvh.index)], tStS0)
qk_mma.set(tcgen05.Field.ACCUMULATE, True)
cute.arch.fence_view_async_tmem_store()
sh.commit()
softmax_done_bar.arrive_and_wait()
pv_mma.set(tcgen05.Field.ACCUMULATE, kt != 0)
if not self.use_smem_p:
# TMEM-P: PV reads P from TMEM
for kb in cutlass.range(cute.size(tOrP0, mode=[2]), unroll_full=True):
cute.gemm(pv_mma, tOtO0, tOrP0[(None,None,kb)], tCrV[(None,None,kb,kvh.index)], tOtO0)
pv_mma.set(tcgen05.Field.ACCUMULATE, True)
else:
# SMEM-P: PV reads P from SMEM
for kb in cutlass.range(cute.size(tCrP, mode=[2]), unroll_full=True):
cute.gemm(pv_mma, tOtO0, tCrP[(None,None,kb,0)], tCrV[(None,None,kb,kvh.index)], tOtO0)
pv_mma.set(tcgen05.Field.ACCUMULATE, True)
cute.arch.fence_view_async_tmem_store()
kvh.release()
acc_pipe.producer_commit(acc_st); acc_st.advance()
final_o_bar.arrive()
acc_pipe.producer_tail(acc_st)
if const_expr(self.n_k_sub_tiles > 1):
# K sub-tiling path (hd=512): serialized with barrier sync
_ksub_bar = pipeline.NamedBarrier(barrier_id=6, num_threads=64)
_v_bar = pipeline.NamedBarrier(barrier_id=7, num_threads=64)
for kt in range(self.n_kv_tiles):
for k_sub in range(self.n_k_sub_tiles):
# Wait for TMA warp: sQ and sK ready
_ksub_bar.arrive_and_wait()
# QK GEMM: load Q from sQ, K from sK, accumulate into S
qk_mma.set(tcgen05.Field.ACCUMULATE, k_sub != 0)
for kb in cutlass.range(cute.size(tCrQ, mode=[2]), unroll_full=True):
cute.gemm(qk_mma, tStS0, tCrQ[(None,None,kb,0)], tCrK[(None,None,kb,0)], tStS0)
qk_mma.set(tcgen05.Field.ACCUMULATE, True)
# After all k_sub: S has full QK for this kt
cute.arch.fence_view_async_tmem_store()
# Signal softmax
softmax_done_bar.arrive() # signal that S is ready
# Wait for V load
_v_bar.arrive_and_wait()
# PV GEMM
pv_mma.set(tcgen05.Field.ACCUMULATE, kt != 0)
if not self.use_smem_p:
for kb in cutlass.range(cute.size(tOrP0, mode=[2]), unroll_full=True):
cute.gemm(pv_mma, tOtO0, tOrP0[(None,None,kb)], tCrV[(None,None,kb,0)], tOtO0)
pv_mma.set(tcgen05.Field.ACCUMULATE, True)
else:
for kb in cutlass.range(cute.size(tCrP, mode=[2]), unroll_full=True):
cute.gemm(pv_mma, tOtO0, tCrP[(None,None,kb,0)], tCrV[(None,None,kb,0)], tOtO0)
pv_mma.set(tcgen05.Field.ACCUMULATE, True)
cute.arch.fence_view_async_tmem_store()
softmax_done_bar.arrive() # signal PV complete for this kt
final_o_bar.arrive()
else:
# Original pipeline path (hd≤256)
qc.reset(); qh = qc.wait_and_advance(); qh.release()
kvc.reset(); pk = kvc.try_wait()
acc_st = pipeline.make_pipeline_state(pipeline.PipelineUserType.Producer, self.num_acc_stage)
acc_pipe.producer_acquire(acc_st)
for kt in range(self.n_kv_tiles):
kvh = kvc.wait_and_advance(pk); pk = cutlass.Boolean(1)
sh = s_prod.acquire_and_advance()
qk_mma.set(tcgen05.Field.ACCUMULATE, False)
for kb in cutlass.range(cute.size(tCrQ, mode=[2]), unroll_full=True):
cute.gemm(qk_mma, tStS0, tCrQ[(None,None,kb,0)], tCrK[(None,None,kb,kvh.index)], tStS0)
qk_mma.set(tcgen05.Field.ACCUMULATE, True)
cute.arch.fence_view_async_tmem_store()
sh.commit()
softmax_done_bar.arrive_and_wait()
pv_mma.set(tcgen05.Field.ACCUMULATE, kt != 0)
if not self.use_smem_p:
for kb in cutlass.range(cute.size(tOrP0, mode=[2]), unroll_full=True):
cute.gemm(pv_mma, tOtO0, tOrP0[(None,None,kb)], tCrV[(None,None,kb,kvh.index)], tOtO0)
pv_mma.set(tcgen05.Field.ACCUMULATE, True)
else:
for kb in cutlass.range(cute.size(tCrP, mode=[2]), unroll_full=True):
cute.gemm(pv_mma, tOtO0, tCrP[(None,None,kb,0)], tCrV[(None,None,kb,kvh.index)], tOtO0)
pv_mma.set(tcgen05.Field.ACCUMULATE, True)
cute.arch.fence_view_async_tmem_store()
kvh.release()
acc_pipe.producer_commit(acc_st); acc_st.advance()
final_o_bar.arrive()
acc_pipe.producer_tail(acc_st)
# ===== SOFTMAX + CORRECTION EPILOGUE warps =====
if warp_idx < self.mma_warp_id: