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[Runtime] Reorganize PagedKVCache attn kernel invocation #17237

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Merged
tqchen merged 1 commit into from
Aug 4, 2024
Merged

[Runtime] Reorganize PagedKVCache attn kernel invocation #17237

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2 changes: 1 addition & 1 deletion src/relax/transform/fuse_ops.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -646,7 +646,7 @@ class FunctionCreator : public ExprMutator {
return tvm::tir::UndefinedVars(prim_value->value).empty();
} else if (const auto* shape_expr = expr.as<ShapeExprNode>()) {
return std::all_of(shape_expr->values.begin(), shape_expr->values.end(),
[this](const PrimExpr& e) { return tvm::tir::UndefinedVars(e).empty(); });
[](const PrimExpr& e) { return tvm::tir::UndefinedVars(e).empty(); });
}
return false;
}
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127 changes: 64 additions & 63 deletions src/runtime/relax_vm/paged_kv_cache.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -1535,7 +1535,7 @@ class PagedAttentionKVCacheObj : public AttentionKVCacheObj {
CHECK_EQ(chunked_block_ids_arr[num_depths_ - 1].size(), cur_batch_size_);
}

append_before_attn_ = !support_sliding_window_ && num_depths_ == 1 && use_decode_kernel_[0];
append_before_attn_ = !support_sliding_window_ && use_decode_kernel_.back();
if (NeedKernelBeginForward() && num_qo_heads_ / num_kv_heads_ >= 4) {
// When GQA group size is at least 4 and FlashInfer is enabled,
// we always use prefill kernel for better performance.
Expand Down Expand Up @@ -2220,39 +2220,33 @@ class PagedAttentionKVCacheObj : public AttentionKVCacheObj {
return;
}

if (append_before_attn_) {
if (!support_sliding_window_) {
if (!append_before_attn_) {
if (is_chain_) {
f_attention_prefill_ragged_begin_forward_.value()(
temp_attn_workspace_[0], cur_append_lengths_indptr_host_.as_ndarray(),
cur_append_lengths_indptr_host_.as_ndarray(), cur_batch_size_, num_qo_heads_,
num_kv_heads_, head_dim_, copy_stream_);
} else {
LOG(FATAL) << "Kernel BeginForward doesn't support tree attn.";
}
}
for (int d = 0; d < num_depths_; ++d) {
if (page_indices_on_depths_view_[d]->shape[0] == 0) {
continue;
}
CHECK(!support_sliding_window_) << "Kernel BeginForward doesn't support sliding window.";
if (use_decode_kernel_[d]) {
f_attention_decode_begin_forward_.value()(
/*depth=*/0, temp_attn_workspace_[1], page_indptr_on_depths_host_[0].as_ndarray(),
last_page_len_on_depths_host_[0].as_ndarray(), num_qo_heads_, num_kv_heads_, head_dim_,
d, temp_attn_workspace_[d + 1], page_indptr_on_depths_host_[d].as_ndarray(),
last_page_len_on_depths_host_[d].as_ndarray(), num_qo_heads_, num_kv_heads_, head_dim_,
page_size_,
/*rotary_mode=*/rope_mode_ == RoPEMode::kInline, copy_stream_);
}
} else {
f_attention_prefill_ragged_begin_forward_.value()(
temp_attn_workspace_[0], cur_append_lengths_indptr_host_.as_ndarray(),
cur_append_lengths_indptr_host_.as_ndarray(), cur_batch_size_, num_qo_heads_,
num_kv_heads_, head_dim_, copy_stream_);
if (support_sliding_window_) {
return;
}
for (int d = 0; d < num_depths_; ++d) {
if (page_indices_on_depths_view_[d]->shape[0] == 0) {
continue;
}
if (use_decode_kernel_[d]) {
f_attention_decode_begin_forward_.value()(
d, temp_attn_workspace_[d + 1], page_indptr_on_depths_host_[d].as_ndarray(),
last_page_len_on_depths_host_[d].as_ndarray(), num_qo_heads_, num_kv_heads_,
head_dim_, page_size_,
/*rotary_mode=*/rope_mode_ == RoPEMode::kInline, copy_stream_);
} else {
f_attention_prefill_begin_forward_.value()(
/*depth=*/d, temp_attn_workspace_[d + 1], qo_indptr_on_depths_host_[d].as_ndarray(),
page_indptr_on_depths_host_[d].as_ndarray(),
static_cast<int>(page_indptr_on_depths_host_[d].size()) - 1, num_qo_heads_,
num_kv_heads_, head_dim_, page_size_, copy_stream_);
}
} else {
f_attention_prefill_begin_forward_.value()(
/*depth=*/d, temp_attn_workspace_[d + 1], qo_indptr_on_depths_host_[d].as_ndarray(),
page_indptr_on_depths_host_[d].as_ndarray(),
static_cast<int>(page_indptr_on_depths_host_[d].size()) - 1, num_qo_heads_,
num_kv_heads_, head_dim_, page_size_, copy_stream_);
}
}
}
Expand All @@ -2271,15 +2265,11 @@ class PagedAttentionKVCacheObj : public AttentionKVCacheObj {
PackedFunc f_decode =
!support_sliding_window_ ? f_attention_decode_ : f_attention_decode_sliding_window_;
CHECK_GE(num_depths_, 1) << "The number of effective depths must be greater or equal to 1.";
if (append_before_attn_) {
f_decode(
/*depth=*/0, q_data, pages_[local_layer_id], page_indptr_on_depths_view_[0],
page_indices_on_depths_view_[0], length_info_on_depths_view_[0],
k_rope_pos_offset_view_[0], q_rope_position_map_view_, output, merged_attn_scores_view_,
/*rotary_mode=*/rope_mode_ == RoPEMode::kInline, rotary_scale_, rotary_theta_,
attn_score_scaling_factor);
} else {
// Compute appended text self-attention

bool is_first_kernel = true;
if (!append_before_attn_) {
// The first part of attention, which only involves the q and the newly appended k/v.
is_first_kernel = false;
if (is_chain_) {
// If the batch does not form a tree, use raggedness prefill kernel.
f_attention_prefill_ragged_(q_data, cur_append_length_indptr_view_, k_data, v_data,
Expand All @@ -2301,32 +2291,43 @@ class PagedAttentionKVCacheObj : public AttentionKVCacheObj {
merged_attn_scores_view_, /*rotary_mode=*/rope_mode_ == RoPEMode::kInline,
rotary_scale_, rotary_theta_, attn_score_scaling_factor, cur_batch_size_);
}
}

for (int d = 0; d < num_depths_; ++d) {
if (page_indices_on_depths_view_[d]->shape[0] == 0) {
continue;
}
if (use_decode_kernel_[d]) {
// Use decode kernel for depth d
f_decode(/*depth=*/d, q_data, pages_[local_layer_id], page_indptr_on_depths_view_[d],
page_indices_on_depths_view_[d], length_info_on_depths_view_[d],
k_rope_pos_offset_view_[d], q_rope_position_map_view_, temp_attn_output_view_,
temp_attn_scores_view_,
/*rotary_mode=*/rope_mode_ == RoPEMode::kInline, rotary_scale_, rotary_theta_,
attn_score_scaling_factor);
} else {
// Use prefill kernel for depth d
f_prefill(
/*depth=*/d, q_data, qo_indptr_on_depths_view_[d], pages_[local_layer_id],
page_indptr_on_depths_view_[d], page_indices_on_depths_view_[d],
length_info_on_depths_view_[d], k_rope_pos_offset_view_[d], q_rope_position_map_view_,
temp_attn_output_view_, temp_attn_scores_view_,
/*causal=*/0,
/*rotary_mode=*/rope_mode_ == RoPEMode::kInline, rotary_scale_, rotary_theta_,
attn_score_scaling_factor);
}
for (int d = 0; d < num_depths_; ++d) {
if (page_indices_on_depths_view_[d]->shape[0] == 0) {
continue;
}
NDArray attn_output;
NDArray attn_scores;
if (is_first_kernel) {
attn_output = output;
attn_scores = merged_attn_scores_view_;
} else {
attn_output = temp_attn_output_view_;
attn_scores = temp_attn_scores_view_;
}
if (use_decode_kernel_[d]) {
// Use decode kernel for depth d
f_decode(/*depth=*/d, q_data, pages_[local_layer_id], page_indptr_on_depths_view_[d],
page_indices_on_depths_view_[d], length_info_on_depths_view_[d],
k_rope_pos_offset_view_[d], q_rope_position_map_view_, attn_output, attn_scores,
/*rotary_mode=*/rope_mode_ == RoPEMode::kInline, rotary_scale_, rotary_theta_,
attn_score_scaling_factor);
} else {
// Use prefill kernel for depth d
f_prefill(/*depth=*/d, q_data, qo_indptr_on_depths_view_[d], pages_[local_layer_id],
page_indptr_on_depths_view_[d], page_indices_on_depths_view_[d],
length_info_on_depths_view_[d], k_rope_pos_offset_view_[d],
q_rope_position_map_view_, attn_output, attn_scores, /*causal=*/0,
/*rotary_mode=*/rope_mode_ == RoPEMode::kInline, rotary_scale_, rotary_theta_,
attn_score_scaling_factor);
}

if (!is_first_kernel) {
f_merge_inplace_(output, merged_attn_scores_view_, temp_attn_output_view_,
temp_attn_scores_view_);
} else {
is_first_kernel = false;
}
}
}
Expand Down