rcu: Consolidate expedited GP tracing into rcu_exp_gp_seq_snap()

This commit moves some duplicate code from synchronize_rcu_expedited()
and synchronize_sched_expedited() into rcu_exp_gp_seq_snap().  This
doesn't save lines of code, but does eliminate a "tell me twice" issue.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index fd86eca..5b1c8fd 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3392,8 +3392,12 @@ static void rcu_exp_gp_seq_end(struct rcu_state *rsp)
 }
 static unsigned long rcu_exp_gp_seq_snap(struct rcu_state *rsp)
 {
+       unsigned long s;
+
        smp_mb(); /* Caller's modifications seen first by other CPUs. */
-       return rcu_seq_snap(&rsp->expedited_sequence);
+       s = rcu_seq_snap(&rsp->expedited_sequence);
+       trace_rcu_exp_grace_period(rsp->name, s, TPS("snap"));
+       return s;
 }
 static bool rcu_exp_gp_seq_done(struct rcu_state *rsp, unsigned long s)
 {
@@ -3898,8 +3902,6 @@ void synchronize_sched_expedited(void)
 
        /* Take a snapshot of the sequence number.  */
        s = rcu_exp_gp_seq_snap(rsp);
-       trace_rcu_exp_grace_period(rsp->name, s, TPS("snap"));
-
        if (exp_funnel_lock(rsp, s))
                return;  /* Someone else did our work for us. */
 

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index b6d5dde..529a440 100644 (file)
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -748,8 +748,6 @@ void synchronize_rcu_expedited(void)
        }
 
        s = rcu_exp_gp_seq_snap(rsp);
-       trace_rcu_exp_grace_period(rsp->name, s, TPS("snap"));
-
        if (exp_funnel_lock(rsp, s))
                return;  /* Someone else did our work for us. */