From: Paul E. McKenney Date: Mon, 11 Dec 2023 19:55:17 +0000 (-0800) Subject: doc: Clarify use of slab constructors and SLAB_TYPESAFE_BY_RCU X-Git-Tag: v6.9-rc1~213^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=56823e9f60f0eedb9981f28b664232a9cace1015;p=thirdparty%2Fkernel%2Flinux.git doc: Clarify use of slab constructors and SLAB_TYPESAFE_BY_RCU This commit explicitly states that you should initialize any locks to be used by readers in your SLAB_TYPESAFE_BY_RCU constructor. Signed-off-by: Paul E. McKenney Signed-off-by: Boqun Feng --- diff --git a/Documentation/RCU/whatisRCU.rst b/Documentation/RCU/whatisRCU.rst index 246ce0d0b4d11..872ac665223fb 100644 --- a/Documentation/RCU/whatisRCU.rst +++ b/Documentation/RCU/whatisRCU.rst @@ -963,8 +963,8 @@ unfortunately any spinlock in a ``SLAB_TYPESAFE_BY_RCU`` object must be initialized after each and every call to kmem_cache_alloc(), which renders reference-free spinlock acquisition completely unsafe. Therefore, when using ``SLAB_TYPESAFE_BY_RCU``, make proper use of a reference counter. -(Those willing to use a kmem_cache constructor may also use locking, -including cache-friendly sequence locking.) +(Those willing to initialize their locks in a kmem_cache constructor +may also use locking, including cache-friendly sequence locking.) With traditional reference counting -- such as that implemented by the kref library in Linux -- there is typically code that runs when the last