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Subject[PATCH tip/core/rcu 14/16] rcu: Consolidate expedited GP tracing into rcu_exp_gp_seq_snap()
Date
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>
---
kernel/rcu/tree.c | 8 +++++---
kernel/rcu/tree_plugin.h | 2 --
2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index fd86eca9478e..5b1c8fd89af0 100644
--- 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 b6d5dde6eab9..529a44085a63 100644
--- 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. */

--
2.5.2
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