[PATCH v8 2/8] srcu: Add notrace variants of srcu_read_{lock,unlock}

Joel Fernandes
2018-05-30T00:05:19Z

From: Paul McKenney <paulmck@linux.vnet.ibm.com>

This is needed for a future tracepoint patch that uses srcu, and to make
sure it doesn't call into lockdep.

tracepoint code already calls notrace variants for rcu_read_lock_sched
so this patch does the same for srcu which will be used in a later
patch. Keeps it consistent with rcu-sched.

[Joel: Added commit message]
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Paul McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
---
include/linux/srcu.h | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index 33c1c698df09..2ec618979b20 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -161,6 +161,16 @@ static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp)
return retval;
}

+/* Used by tracing, cannot be traced and cannot invoke lockdep. */
+static inline notrace int
+srcu_read_lock_notrace(struct srcu_struct *sp) __acquires(sp)
+{
+ int retval;
+
+ retval = __srcu_read_lock(sp);
+ return retval;
+}
+
/**
* srcu_read_unlock - unregister a old reader from an SRCU-protected structure.
* @sp: srcu_struct in which to unregister the old reader.
@@ -175,6 +185,13 @@ static inline void srcu_read_unlock(struct srcu_struct *sp, int idx)
__srcu_read_unlock(sp, idx);
}

+/* Used by tracing, cannot be traced and cannot call lockdep. */
+static inline notrace void
+srcu_read_unlock_notrace(struct srcu_struct *sp, int idx) __releases(sp)
+{
+ __srcu_read_unlock(sp, idx);
+}
+
/**
* smp_mb__after_srcu_read_unlock - ensure full ordering after srcu_read_unlock
*
--
2.17.0.921.gf22659ad46-goog