Update docstring

jax/_src/config.py

@@ -1236,11 +1236,11 @@ def _update_jax_memories_thread_local(val):
 compilation_cache_max_size = define_int_state(
     name='jax_compilation_cache_max_size',
     default=-1,
-    help=('The maximum size of the persistent compilation cache. '
-          'This value is used in the LRU cache eviction. The cache eviction '
-          'happens when the size of the cache directort would be larger than '
-          'the size specified here (in bytes). A special value of -1 '
-          'indicates that the size of the cache directory can be infinite.'),
+    help=('The maximum size (in bytes) allowed for the persistent compilation '
+          'cache. When set, this value triggers the LRU cache eviction once the '
+          'total cache directory size exceeds the specified limit. A special '
+          'value of -1 indicates no upper limit, allowing the cache size to '
+          'grow indefinitely.'),
 )
 
 default_dtype_bits = define_enum_state(

jax/_src/lru_cache.py

@@ -40,8 +40,8 @@ class Impl:
     def __init__(self, path: str, *, max_size: int, timeout_secs: float | None=10):
         path = pathlib.Path(path)
 
-        if filelock is None:
-            raise RuntimeError("Please install filelock to use the LRUCache")
+        if max_size != -1 and filelock is None:
+            raise RuntimeError("Please install filelock package to set `jax_compilation_cache_max_size`")
 
         self.path = path
         self.max_size = max_size