Add unit test on page_size > 1 and mla and integration test for Flash Attention 3 (sgl-project#4760)

Author: yubofredwang

python/sglang/srt/layers/attention/flashattention_backend.py

@@ -548,8 +548,9 @@ def forward_extend(
         # Use Flash Attention for prefill
         if not self.use_mla:
             # Do multi-head attention
-            kv_cache = forward_batch.token_to_kv_pool.get_kv_buffer(layer.layer_id)
-            key_cache, value_cache = kv_cache[0], kv_cache[1]
+            key_cache, value_cache = forward_batch.token_to_kv_pool.get_kv_buffer(
+                layer.layer_id
+            )
             key_cache = key_cache.view(
                 -1, self.page_size, layer.tp_k_head_num, layer.head_dim
             )
@@ -592,7 +593,6 @@ def forward_extend(
             c_kv_cache = c_kv.view(
                 -1, self.page_size, layer.tp_v_head_num, layer.v_head_dim
             )
-
             q_all = q.contiguous().view(-1, layer.tp_q_head_num, layer.head_dim)
             q_nope = q_all[:, :, : layer.v_head_dim]
             q_rope = q_all[:, :, layer.v_head_dim :]
@@ -659,8 +659,10 @@ def forward_decode(
 
         if not self.use_mla:
             # Do multi-head attention
-            kv_cache = forward_batch.token_to_kv_pool.get_kv_buffer(layer.layer_id)
-            key_cache, value_cache = kv_cache[0], kv_cache[1]
+
+            key_cache, value_cache = forward_batch.token_to_kv_pool.get_kv_buffer(
+                layer.layer_id
+            )
             key_cache = key_cache.view(
                 -1, self.page_size, layer.tp_k_head_num, layer.head_dim
             )

python/sglang/srt/layers/quantization/__init__.py

@@ -63,10 +63,6 @@ def override_quantization_method(self, *args, **kwargs):
 from sglang.srt.layers.quantization.moe_wna16 import MoeWNA16Config
 from sglang.srt.layers.quantization.w8a8_fp8 import W8A8Fp8Config
 from sglang.srt.layers.quantization.w8a8_int8 import W8A8Int8Config
-from sglang.srt.layers.vocab_parallel_embedding import (
-    ParallelLMHead,
-    UnquantizedEmbeddingMethod,
-)
 
 # Base quantization methods that don't depend on vllm
 BASE_QUANTIZATION_METHODS: Dict[str, Type[QuantizationConfig]] = {
@@ -176,6 +172,13 @@ def get_linear_quant_method(
     prefix: str,
     linear_method_cls: type,
 ):
+    # Move import here to avoid circular import. This is only used in monkey patching
+    # of vllm's QuantizationConfig.
+    from sglang.srt.layers.vocab_parallel_embedding import (
+        ParallelLMHead,
+        UnquantizedEmbeddingMethod,
+    )
+
     cloned_config = deepcopy(config)
     parallel_lm_head_quantized = (
         isinstance(layer, ParallelLMHead) and cloned_config.lm_head_quantized