refactor: replace magic layout ints with TensorLayout enum

- Add TensorLayout enum (C++ + Python) to replace magic layout ints
- Add C10_CUDA_CHECK post-launch error checking to all kernel entries
- Add CUDAGuard + freqs_cis shape validation to rotary_emb.cu
- Cache SM count to eliminate per-call cudaDeviceGetAttribute
- Add DISPATCH_CAUSAL_MASK macro to deduplicate dispatcher if/else
- Convert mask type hints from X|None to Optional[X]
This commit is contained in:
2026-08-01 11:05:52 +08:00
parent 3639b50b4a
commit 7feeb0b93e
9 changed files with 91 additions and 59 deletions
+41 -45
View File
@@ -14,18 +14,50 @@
#include "attn_paged_decode_split_kv_mma.cuh"
#endif
// Cached SM count — cudaDeviceGetAttribute is a host-side call that was
// invoked on every decode/paged-decode launch. Cache per-device so multi-GPU
// setups with heterogeneous GPUs still get the right count, while the common
// single-GPU path hits the cache after the first call.
inline int get_sm_count() {
int dev = 0;
cudaGetDevice(&dev);
static int cached_dev = -1;
static int cached_count = 0;
if (dev != cached_dev) {
cudaDeviceGetAttribute(&cached_count, cudaDevAttrMultiProcessorCount, dev);
cached_dev = dev;
}
return cached_count;
}
// Split-KV: compute number of splits to fill all SMs for small-batch decode.
// Caps splits so each split processes at least `min_tiles_per_split` tiles,
// avoiding excessive loop/prologue overhead when tiles are small.
inline int compute_num_splits(int base_blocks, int tiles_total,
int min_tiles_per_split = 1) {
int sm_count = 0;
cudaDeviceGetAttribute(&sm_count, cudaDevAttrMultiProcessorCount, 0);
int min_tiles_per_split = 1) {
int sm_count = get_sm_count();
int n = (2 * sm_count + base_blocks - 1) / base_blocks;
int max_by_work = tiles_total / min_tiles_per_split;
return std::max(1, std::min(n, std::min(max_by_work, MAX_SPLITS)));
}
// Dispatch IsCausal × HasMask — eliminates the duplicated 4-way if/else
// ladder that appeared in each dispatch_* function. FN must be a function
// template <int HEAD_DIM, bool IsCausal, bool HasMask>; HEAD_DIM is forwarded
// as the first template argument so callers only spell it once.
//
// Usage: DISPATCH_CAUSAL_MASK(is_causal, has_mask, launch_decode_mma, HEAD_DIM, p, group_size);
#define DISPATCH_CAUSAL_MASK(is_causal, has_mask, FN, HEAD_DIM, ...) \
do { \
if (is_causal) { \
if (has_mask) FN<HEAD_DIM, true, true>(__VA_ARGS__); \
else FN<HEAD_DIM, true, false>(__VA_ARGS__); \
} else { \
if (has_mask) FN<HEAD_DIM, false, true>(__VA_ARGS__); \
else FN<HEAD_DIM, false, false>(__VA_ARGS__); \
} \
} while (0)
// ======================================================================
// Prefill
// ======================================================================
@@ -56,21 +88,9 @@ static inline void dispatch_prefill(AttentionParams<bf16>& p) {
bool has_mask = (p.use_mask && p.mask);
#ifndef ASTRAI_NO_MMA
if (is_causal) {
if (has_mask) launch_prefill_mma<HEAD_DIM, true, true>(p);
else launch_prefill_mma<HEAD_DIM, true, false>(p);
} else {
if (has_mask) launch_prefill_mma<HEAD_DIM, false, true>(p);
else launch_prefill_mma<HEAD_DIM, false, false>(p);
}
DISPATCH_CAUSAL_MASK(is_causal, has_mask, launch_prefill_mma, HEAD_DIM, p);
#else
if (is_causal) {
if (has_mask) launch_prefill_scalar<HEAD_DIM, true, true>(p);
else launch_prefill_scalar<HEAD_DIM, true, false>(p);
} else {
if (has_mask) launch_prefill_scalar<HEAD_DIM, false, true>(p);
else launch_prefill_scalar<HEAD_DIM, false, false>(p);
}
DISPATCH_CAUSAL_MASK(is_causal, has_mask, launch_prefill_scalar, HEAD_DIM, p);
#endif
}
@@ -116,21 +136,9 @@ static inline void dispatch_decode(AttentionParams<bf16>& p) {
int group_size = p.q_head / p.kv_head;
#ifndef ASTRAI_NO_MMA
if (is_causal) {
if (has_mask) launch_decode_mma<HEAD_DIM, true, true>(p, group_size);
else launch_decode_mma<HEAD_DIM, true, false>(p, group_size);
} else {
if (has_mask) launch_decode_mma<HEAD_DIM, false, true>(p, group_size);
else launch_decode_mma<HEAD_DIM, false, false>(p, group_size);
}
DISPATCH_CAUSAL_MASK(is_causal, has_mask, launch_decode_mma, HEAD_DIM, p, group_size);
#else
if (is_causal) {
if (has_mask) launch_decode_scalar<HEAD_DIM, true, true>(p, group_size);
else launch_decode_scalar<HEAD_DIM, true, false>(p, group_size);
} else {
if (has_mask) launch_decode_scalar<HEAD_DIM, false, true>(p, group_size);
else launch_decode_scalar<HEAD_DIM, false, false>(p, group_size);
}
DISPATCH_CAUSAL_MASK(is_causal, has_mask, launch_decode_scalar, HEAD_DIM, p, group_size);
#endif
attn_decode_combine_kernel<<<p.batch * p.q_head, p.head_dim>>>(p);
@@ -174,21 +182,9 @@ static inline void dispatch_paged_decode(PagedAttentionParams<bf16>& p) {
int group_size = p.q_head / p.kv_head;
#ifndef ASTRAI_NO_MMA
if (is_causal) {
if (has_mask) launch_paged_decode_mma<HEAD_DIM, true, true>(p, group_size);
else launch_paged_decode_mma<HEAD_DIM, true, false>(p, group_size);
} else {
if (has_mask) launch_paged_decode_mma<HEAD_DIM, false, true>(p, group_size);
else launch_paged_decode_mma<HEAD_DIM, false, false>(p, group_size);
}
DISPATCH_CAUSAL_MASK(is_causal, has_mask, launch_paged_decode_mma, HEAD_DIM, p, group_size);
#else
if (is_causal) {
if (has_mask) launch_paged_decode_scalar<HEAD_DIM, true, true>(p, group_size);
else launch_paged_decode_scalar<HEAD_DIM, true, false>(p, group_size);
} else {
if (has_mask) launch_paged_decode_scalar<HEAD_DIM, false, true>(p, group_size);
else launch_paged_decode_scalar<HEAD_DIM, false, false>(p, group_size);
}
DISPATCH_CAUSAL_MASK(is_causal, has_mask, launch_paged_decode_scalar, HEAD_DIM, p, group_size);
#endif
paged_attn_decode_combine_kernel<<<p.batch * p.q_head, p.head_dim>>>(p);