From ee90848499b169070dbf85a4276a45ccbb7ff7d3 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 5 Nov 2025 12:32:04 -0800 Subject: srcu: Create a DEFINE_SRCU_FAST() This commit creates DEFINE_SRCU_FAST() and DEFINE_STATIC_SRCU_FAST() macros that are similar to DEFINE_SRCU() and DEFINE_STATIC_SRCU(), but which create srcu_struct structures that are usable only by readers initiated by srcu_read_lock_fast() and friends. This commit does make DEFINE_SRCU_FAST() available to modules, in which case the per-CPU srcu_data structures are not created at compile time, but rather at module-load time. This means that the >srcu_reader_flavor field of the srcu_data structure is not available. Therefore, this commit instead creates an ->srcu_reader_flavor field in the srcu_struct structure, adds arguments to the DEFINE_SRCU()-related macros to initialize this new field, and extends the checks in the __srcu_check_read_flavor() function to include this new field. This commit also allows dynamically allocated srcu_struct structure to be marked for SRCU-fast readers. It does so by defining a new init_srcu_struct_fast() function that marks the specified srcu_struct structure for use by srcu_read_lock_fast() and friends. Signed-off-by: Paul E. McKenney Cc: Mathieu Desnoyers Cc: Steven Rostedt Cc: Sebastian Andrzej Siewior Cc: Signed-off-by: Frederic Weisbecker --- include/linux/notifier.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/notifier.h') diff --git a/include/linux/notifier.h b/include/linux/notifier.h index b42e64734968..01b6c9d9956f 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -109,7 +109,7 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); .mutex = __MUTEX_INITIALIZER(name.mutex), \ .head = NULL, \ .srcuu = __SRCU_USAGE_INIT(name.srcuu), \ - .srcu = __SRCU_STRUCT_INIT(name.srcu, name.srcuu, pcpu), \ + .srcu = __SRCU_STRUCT_INIT(name.srcu, name.srcuu, pcpu, 0), \ } #define ATOMIC_NOTIFIER_HEAD(name) \ -- cgit v1.2.3