Sync from v0.13

tests/v1/kv_offload/test_cpu_offloading.py

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+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import socket
+import time
+
+import msgspec
+import msgspec.msgpack
+import pytest
+import zmq
+from tqdm import tqdm
+
+from vllm import LLM, SamplingParams, TokensPrompt
+from vllm.config import KVEventsConfig, KVTransferConfig
+from vllm.distributed.kv_events import BlockStored, KVEventBatch
+from vllm.platforms import current_platform
+from vllm.utils.system_utils import set_env_var
+
+CPU_BLOCK_SIZES = [48]
+ATTN_BACKENDS = ["FLASH_ATTN"]
+
+if current_platform.is_cuda():
+    ATTN_BACKENDS.append("FLASHINFER")
+elif current_platform.is_rocm():
+    ATTN_BACKENDS = ["TRITON_ATTN"]
+
+
+class MockSubscriber:
+    """Helper class to receive and verify published events"""
+
+    def __init__(
+        self,
+        endpoint: str,
+        topic: str,
+    ):
+        self.ctx = zmq.Context.instance()
+        self.topic_bytes = topic.encode("utf-8")
+
+        # Set up subscriber socket
+        self.sub = self.ctx.socket(zmq.SUB)
+        self.sub.setsockopt(zmq.SUBSCRIBE, self.topic_bytes)
+        self.sub.connect(endpoint)
+
+        self.decoder = msgspec.msgpack.Decoder(type=KVEventBatch)
+
+    def get_new_cpu_stored_events(self) -> list[BlockStored]:
+        cpu_stored_events: list[BlockStored] = []
+
+        poller = zmq.Poller()
+        poller.register(self.sub, zmq.POLLIN)
+
+        timeout = 1000  # 1 second
+        while True:
+            events = dict(poller.poll(timeout))
+
+            if events.get(self.sub) != zmq.POLLIN:
+                return cpu_stored_events
+
+            topic_bytes, _, payload = self.sub.recv_multipart()
+
+            assert topic_bytes == self.topic_bytes
+
+            event_batch = self.decoder.decode(payload)
+            assert isinstance(event_batch, KVEventBatch)
+            for event in event_batch.events:
+                if isinstance(event, BlockStored) and event.medium == "CPU":
+                    cpu_stored_events.append(event)
+                    timeout = 100
+
+    def close(self):
+        """Clean up resources"""
+        self.sub.close()
+
+
+def _latency_test(llm: LLM, subscriber: MockSubscriber):
+    sampling_params = SamplingParams(max_tokens=1)
+
+    num_times_cpu_better_than_cold = 0
+    num_tests = 10
+    total_cold_time = 0.0
+    total_gpu_hit_time = 0.0
+    total_cpu_hit_time = 0.0
+    prompt_token_ids = [0] * 10001
+    for i in tqdm(range(num_tests), desc="Running tests"):
+        prompt_token_ids[0] = i
+        prompts = [TokensPrompt(prompt_token_ids=prompt_token_ids)]
+
+        # run generation - this should trigger saving KV cache
+        start_time = time.time()
+        llm.generate(prompts, sampling_params, use_tqdm=False)
+        cold_time = time.time() - start_time
+        total_cold_time += cold_time
+
+        # run generation again - should hit the GPU prefix cache
+        start_time = time.time()
+        llm.generate(prompts, sampling_params, use_tqdm=False)
+        gpu_hit_time = time.time() - start_time
+        total_gpu_hit_time += gpu_hit_time
+
+        # reset prefix cache to avoid GPU hit.
+        llm.reset_prefix_cache()
+
+        assert subscriber.get_new_cpu_stored_events()
+
+        # run generation again - this should trigger loading from CPU
+        start_time = time.time()
+        llm.generate(prompts, sampling_params, use_tqdm=False)
+        cpu_hit_time = time.time() - start_time
+        total_cpu_hit_time += cpu_hit_time
+
+        if cpu_hit_time < cold_time:
+            num_times_cpu_better_than_cold += 1
+
+    print("Average times:")
+    print(f"    Cold: {total_cold_time * 1000 / num_tests:.2f}ms")
+    print(f"    GPU hit: {total_gpu_hit_time * 1000 / num_tests:.2f}ms")
+    print(f"    CPU hit: {total_cpu_hit_time * 1000 / num_tests:.2f}ms")
+
+    assert num_times_cpu_better_than_cold >= 0.8 * num_tests
+
+
+def _accuracy_test(llm: LLM, subscriber: MockSubscriber):
+    sampling_params = SamplingParams(max_tokens=1)
+    cpu_block_size = (
+        llm.llm_engine.vllm_config.kv_transfer_config.kv_connector_extra_config[
+            "block_size"
+        ]
+    )
+
+    subscriber.get_new_cpu_stored_events()
+
+    # prepend prompt to be cpu block aligned
+    prompt = "Let's count to 10. One, two, three, four,"
+    while (
+        len(llm.generate(prompt, use_tqdm=False)[0].prompt_token_ids) % cpu_block_size
+        != 0
+    ):
+        prompt = ". " + prompt
+
+    assert subscriber.get_new_cpu_stored_events()
+
+    test_count = 100
+    success_count = 0
+    for i in range(test_count):
+        if (
+            llm.generate(prompt, sampling_params, use_tqdm=False)[0].outputs[0].text
+            == " five"
+        ):
+            success_count += 1
+
+    assert success_count >= 0.5 * test_count
+
+
+@pytest.mark.parametrize("cpu_block_size", CPU_BLOCK_SIZES)
+@pytest.mark.parametrize("attn_backend", ATTN_BACKENDS)
+def test_cpu_offloading(cpu_block_size: int, attn_backend: str) -> None:
+    """
+    Tests OffloadingConnector with CPUOffloadingSpec.
+    """
+
+    # configure OffloadingConnector (spec_name=CPUOffloadingSpec by default)
+    kv_transfer_config = KVTransferConfig(
+        kv_connector="OffloadingConnector",
+        kv_role="kv_both",
+        kv_connector_extra_config={
+            "num_cpu_blocks": 1000,
+            "block_size": cpu_block_size,
+        },
+    )
+
+    port: int
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+        s.bind(("0.0.0.0", 0))
+        port = s.getsockname()[1]
+
+    events_endpoint = f"tcp://*:{port}"
+    kv_events_config = KVEventsConfig(
+        enable_kv_cache_events=True,
+        publisher="zmq",
+        endpoint=events_endpoint,
+        topic="test",
+    )
+
+    with set_env_var("VLLM_ATTENTION_BACKEND", attn_backend):
+        llm = LLM(
+            model="meta-llama/Llama-3.2-1B-Instruct",
+            gpu_memory_utilization=0.5,
+            kv_events_config=kv_events_config,
+            kv_transfer_config=kv_transfer_config,
+        )
+
+    events_endpoint = events_endpoint.replace("*", "127.0.0.1")
+    subscriber = MockSubscriber(events_endpoint, topic=kv_events_config.topic)
+
+    try:
+        _latency_test(llm, subscriber)
+        _accuracy_test(llm, subscriber)
+    finally:
+        subscriber.close()
+        del llm