Upstreaming hicache bug fixes (#7267)

benchmark/hicache/bench_multiturn.py

@@ -239,7 +239,7 @@ class WorkloadGenerator:
             tokenizer=self.tokenizer,
             dataset_path=args.dataset_path,
         )
-        self.candidate_inputs = [i[0] for i in self.candidate_inputs]
+        self.candidate_inputs = [i.prompt for i in self.candidate_inputs]
 
         init_requests = [
             (i, gen_payload(self.candidate_inputs[i], args.output_length))

python/sglang/srt/managers/cache_controller.py

@@ -30,22 +30,37 @@ logger = logging.getLogger(__name__)
 
 class LayerDoneCounter:
     def __init__(self, num_layers):
-        self.counter = num_layers
-        self.condition = threading.Condition()
+        self.num_layers = num_layers
+        # extra producer and consumer counters for overlap mode
+        self.num_counters = 3
+        self.counters = [num_layers] * self.num_counters
+        self.conditions = [threading.Condition() for _ in range(self.num_counters)]
+        self.producer_index = 0
+        self.consumer_index = 0
+
+    def next_producer(self):
+        return (self.producer_index + 1) % self.num_counters
+
+    def update_producer(self):
+        self.producer_index = self.next_producer()
+        return self.producer_index
+
+    def set_consumer(self, index):
+        self.consumer_index = index
 
     def increment(self):
-        with self.condition:
-            self.counter += 1
-            self.condition.notify_all()
+        with self.conditions[self.producer_index]:
+            self.counters[self.producer_index] += 1
+            self.conditions[self.producer_index].notify_all()
 
     def wait_until(self, threshold):
-        with self.condition:
-            while self.counter <= threshold:
-                self.condition.wait()
+        with self.conditions[self.consumer_index]:
+            while self.counters[self.consumer_index] <= threshold:
+                self.conditions[self.consumer_index].wait()
 
     def reset(self):
-        with self.condition:
-            self.counter = 0
+        with self.conditions[self.producer_index]:
+            self.counters[self.producer_index] = 0
 
 
 class CacheOperation:
@@ -296,7 +311,6 @@ class HiCacheController:
         while not self.stop_event.is_set():
             try:
                 operation = self.load_queue.get(block=True, timeout=1)
-                # time.sleep(18e-6 * len(operation.host_indices))
                 operation.data = self.mem_pool_host.get_flat_data(
                     operation.host_indices
                 )
@@ -320,6 +334,7 @@ class HiCacheController:
             if not self.load_cache_event.is_set():
                 continue
             self.load_cache_event.clear()
+            self.layer_done_counter.update_producer()
 
             batch_operation = None
             while self.load_queue.qsize() > 0:
@@ -331,6 +346,7 @@ class HiCacheController:
             if batch_operation is None:
                 continue
 
+            # start layer-wise KV cache transfer from CPU to GPU
             self.layer_done_counter.reset()
             for i in range(self.mem_pool_host.layer_num):
                 if self.page_size == 1:
@@ -466,6 +482,7 @@ class HiCacheController:
             except Exception as e:
                 logger.error(e)
 
+    # todo (zhiqiang): double buffering to be deprecated
     def write_thread_func_buffer(self):
         aux_thread = threading.Thread(target=self.write_aux_func, daemon=True)
         aux_thread.start()

python/sglang/srt/managers/schedule_batch.py

@@ -659,14 +659,6 @@ class Req:
                 self.prefix_indices, self.last_node = tree_cache.match_prefix(
                     rid=self.rid, key=self.adjust_max_prefix_ids()
                 )
-        elif enable_hierarchical_cache:
-            # in case last_node is evicted during scheduling, we need to update the prefix_indices
-            while self.last_node.evicted:
-                self.prefix_indices = self.prefix_indices[
-                    : -len(self.last_node.host_value)
-                ]
-                self.last_node = self.last_node.parent
-
         self.extend_input_len = len(self.fill_ids) - len(self.prefix_indices)
 
     def adjust_max_prefix_ids(self):
@@ -909,6 +901,9 @@ class ScheduleBatch(ScheduleBatchDisaggregationDecodeMixin):
     # Whether to return hidden states
     return_hidden_states: bool = False
 
+    # hicache pointer for synchronizing data loading from CPU to GPU
+    hicache_consumer_index: int = 0
+
     @classmethod
     def init_new(
         cls,
@@ -1735,6 +1730,7 @@ class ScheduleBatch(ScheduleBatchDisaggregationDecodeMixin):
             token_type_ids=self.token_type_ids,
             spec_algorithm=self.spec_algorithm,
             spec_info=self.spec_info,
+            hicache_consumer_index=self.hicache_consumer_index,
             capture_hidden_mode=(
                 CaptureHiddenMode.FULL
                 if self.return_hidden_states
@@ -1839,6 +1835,7 @@ class ModelWorkerBatch:
     # If set, the output of the batch contains the hidden states of the run.
     capture_hidden_mode: CaptureHiddenMode = None
     spec_num_draft_tokens: Optional[int] = None
+    hicache_consumer_index: int = 0
 
     # Overlap event
     launch_done: Optional[threading.Event] = None

python/sglang/srt/managers/scheduler.py

@@ -565,6 +565,10 @@ class Scheduler(
                     hicache_size=server_args.hicache_size,
                     hicache_write_policy=server_args.hicache_write_policy,
                 )
+                self.tp_worker.register_hicache_layer_transfer_counter(
+                    self.tree_cache.cache_controller.layer_done_counter
+                )
+
             else:
                 self.tree_cache = RadixCache(
                     req_to_token_pool=self.req_to_token_pool,
@@ -1514,8 +1518,13 @@ class Scheduler(
                     self.running_batch.batch_is_full = True
                     break
 
+            # bypass prefix_computed if enable_hierarchical_cache
             req.init_next_round_input(
-                None if prefix_computed else self.tree_cache,
+                (
+                    None
+                    if (prefix_computed and not self.enable_hierarchical_cache)
+                    else self.tree_cache
+                ),
                 self.enable_hierarchical_cache,
             )
 
@@ -1548,9 +1557,6 @@ class Scheduler(
             x for x in self.waiting_queue if x not in set(can_run_list)
         ]
 
-        if self.enable_hierarchical_cache:
-            self.tree_cache.ready_to_load_cache()
-
         if adder.new_chunked_req is not None:
             assert self.chunked_req is None
             self.chunked_req = adder.new_chunked_req
@@ -1574,6 +1580,10 @@ class Scheduler(
             self.server_args.enable_custom_logit_processor,
             chunked_req=self.chunked_req,
         )
+        if self.enable_hierarchical_cache:
+            # todo (zhiqiang): disable cuda graph execution if hicache loading triggered
+            new_batch.hicache_consumer_index = self.tree_cache.ready_to_load_cache()
+
         new_batch.prepare_for_extend()
 
         # Mixed-style chunked prefill
@@ -1649,6 +1659,11 @@ class Scheduler(
         if self.is_generation:
             if self.spec_algorithm.is_none():
                 model_worker_batch = batch.get_model_worker_batch()
+
+                # update the consumer index of hicache to the running batch
+                self.tp_worker.set_hicache_consumer(
+                    model_worker_batch.hicache_consumer_index
+                )
                 if self.pp_group.is_last_rank:
                     logits_output, next_token_ids, can_run_cuda_graph = (
                         self.tp_worker.forward_batch_generation(model_worker_batch)

python/sglang/srt/managers/tp_worker.py

@@ -147,6 +147,15 @@ class TpModelWorker:
         # A reference make this class has the same member as TpModelWorkerClient
         self.worker = self
 
+        self.hicache_layer_transfer_counter = None
+
+    def register_hicache_layer_transfer_counter(self, counter):
+        self.hicache_layer_transfer_counter = counter
+
+    def set_hicache_consumer(self, consumer_index):
+        if self.hicache_layer_transfer_counter is not None:
+            self.hicache_layer_transfer_counter.set_consumer(consumer_index)
+
     def get_worker_info(self):
         return (
             self.max_total_num_tokens,

python/sglang/srt/managers/tp_worker_overlap_thread.py

@@ -88,6 +88,15 @@ class TpModelWorkerClient:
         if self.device == "cpu":
             self.scheduler_stream.synchronize = lambda: None  # No-op for CPU
 
+        self.hicache_layer_transfer_counter = None
+
+    def register_hicache_layer_transfer_counter(self, counter):
+        self.hicache_layer_transfer_counter = counter
+
+    def set_hicache_consumer(self, consumer_index):
+        if self.hicache_layer_transfer_counter is not None:
+            self.hicache_layer_transfer_counter.set_consumer(consumer_index)
+
     def get_worker_info(self):
         return self.worker.get_worker_info()
 
@@ -146,6 +155,8 @@ class TpModelWorkerClient:
             input_ids = model_worker_batch.input_ids
             resolve_future_token_ids(input_ids, self.future_token_ids_map)
 
+            # update the consumer index of hicache to the running batch
+            self.set_hicache_consumer(model_worker_batch.hicache_consumer_index)
             # Run forward
             logits_output, next_token_ids, can_run_cuda_graph = (
                 self.worker.forward_batch_generation(

python/sglang/srt/mem_cache/hiradix_cache.py

@@ -307,7 +307,9 @@ class HiRadixCache(RadixCache):
         return last_node, prefix_indices
 
     def ready_to_load_cache(self):
+        producer_index = self.cache_controller.layer_done_counter.next_producer()
         self.load_cache_event.set()
+        return producer_index
 
     def match_prefix(self, key: List[int], include_evicted=False, **kwargs):
         empty_value = torch.empty((0,), dtype=torch.int64, device=self.device)
@@ -372,6 +374,7 @@ class HiRadixCache(RadixCache):
         new_node.lock_ref = child.lock_ref
         new_node.key = child.key[:split_len]
         new_node.loading = child.loading
+        new_node.hit_count = child.hit_count
 
         # split value and host value if exists
         if child.evicted: