[PATCH 7/8] doc: Clarify use of slab constructors and SLAB_TYPESAFE_BY_RCU

From: Boqun Feng
Date: Thu Jan 25 2024 - 23:00:47 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>

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 <paulmck@xxxxxxxxxx>
---
Documentation/RCU/whatisRCU.rst | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/RCU/whatisRCU.rst b/Documentation/RCU/whatisRCU.rst
index 246ce0d0b4d1..872ac665223f 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
--
2.43.0