Commit 1143c9d9 authored Apr 17, 2023 by SeongJae Park Committed by Vlastimil Babka Jun 08, 2023

mm/slab: break up RCU readers on SLAB_TYPESAFE_BY_RCU example code



The SLAB_TYPESAFE_BY_RCU example code snippet uses a single RCU
read-side critical section for retries.
'Documentation/RCU/rculist_nulls.rst' has similar example code snippet,
and commit da82af04 ("doc: Update and wordsmith rculist_nulls.rst")
broke it up.  Apply the change to SLAB_TYPESAFE_BY_RCU example code
snippet, too.

Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

parent 9ca73f26

include/linux/slab.h

+5 −3

Original line number	Diff line number	Diff line
		@@ -53,16 +53,18 @@
		* stays valid, the trick to using this is relying on an independent
		* object validation pass. Something like:
		*
		* begin:
		* rcu_read_lock();
		* again:
		* obj = lockless_lookup(key);
		* if (obj) {
		* if (!try_get_ref(obj)) // might fail for free objects
		* goto again;
		* rcu_read_unlock();
		* goto begin;
		*
		* if (obj->key != key) { // not the object we expected
		* put_ref(obj);
		* goto again;
		* rcu_read_unlock();
		* goto begin;
		* }
		* }
		* rcu_read_unlock();