[HICache]: Support 3FS-Store with page_first_direct layout (#11460)

docs/advanced_features/hicache_best_practices.md

@@ -67,6 +67,7 @@ python3 -m sglang.launch_server \
   --enable-hierarchical-cache \
   --hicache-ratio 2 \
   --hicache-size 0 \
+  --hicache-mem-layout page_first_direct \
   --hicache-io-backend direct \
   --hicache-write-policy write_through \
   --hicache-storage-backend hf3fs \
@@ -86,6 +87,7 @@ python3 -m sglang.launch_server \
   --page-size 64 \
   --hicache-ratio 2 \
   --hicache-size 0 \
+  --hicache-mem-layout page_first_direct \
   --hicache-io-backend direct \
   --hicache-write-policy write_through \
   --hicache-storage-backend hf3fs \
@@ -115,7 +117,8 @@ python3 -m sglang.launch_server \
   --enable-hierarchical-cache \
   --hicache-ratio 2 \
   --hicache-size 0 \
-  --hicache-mem-layout page_first \
+  --hicache-mem-layout page_first_direct \
+  --hicache-io-backend direct \
   --hicache-write-policy write_through \
   --hicache-storage-backend hf3fs \
   --hicache-storage-prefetch-policy wait_complete \
@@ -140,8 +143,8 @@ python3 -m sglang.launch_server \
   --page-size 64 \
   --enable-hierarchical-cache \
   --hicache-ratio 2 \
-  --hicache-mem-layout page_first \
-  --hicache-io-backend kernel \
+  --hicache-mem-layout page_first_direct \
+  --hicache-io-backend direct \
   --hicache-storage-backend mooncake \
   --hicache-write-policy write_through \
   --hicache-storage-prefetch-policy timeout

python/sglang/srt/mem_cache/storage/backend_factory.py

@@ -170,7 +170,7 @@ class StorageBackendFactory:
             return backend
         elif backend_name == "hf3fs":
             # Calculate bytes_per_page based on memory pool layout
-            if mem_pool_host.layout == "page_first":
+            if mem_pool_host.layout in ["page_first", "page_first_direct"]:
                 bytes_per_page = (
                     mem_pool_host.get_ksize_per_token() * mem_pool_host.page_size
                 )

python/sglang/srt/mem_cache/storage/hf3fs/storage_hf3fs.py

@@ -501,8 +501,12 @@ class HiCacheHF3FS(HiCacheStorage):
 
     def register_mem_pool_host(self, mem_pool_host: HostKVCache):
         super().register_mem_pool_host(mem_pool_host)
-        self.is_zero_copy = self.mem_pool_host.layout == "page_first"
-        logger.info(f"{self.is_zero_copy=}")
+        self.is_zero_copy = self.mem_pool_host.layout in [
+            "page_first",
+            "page_first_direct",
+        ]
+
+        logger.info(f"{self.is_zero_copy=}, layout={self.mem_pool_host.layout}")
 
     def _get_mha_zero_copy_keys(self, keys: List[str]) -> List[str]:
         _keys = []

test/srt/hicache/test_hicache_storage_3fs_backend.py

@@ -76,6 +76,8 @@ class TestHf3fsBackendAccuracy(HiCacheStorage3FSBackendBaseMixin, CustomTestCase
         server_args, env_vars = super()._get_additional_server_args_and_env()
         server_args["--hicache-ratio"] = 1.5
         server_args["--tp-size"] = 2
+        server_args["--hicache-mem-layout"] = "page_first_direct"
+        server_args["--hicache-io-backend"] = "direct"
         return server_args, env_vars
 
     def test_eval_accuracy(self):