[PATCH tip/core/rcu 6/8] rcu: Eliminate check_for_new_grace_period() wrapper function

From: Paul E. McKenney
Date: Fri Apr 12 2013 - 19:33:11 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>

One of the calls to check_for_new_grace_period() is now redundant due to
an immediately preceding call to note_gp_changes(). Eliminating this
redundant call leaves a single caller, which is simpler if inlined.
This commit therefore eliminates the redundant call and inlines the
body of check_for_new_grace_period() into the single remaining call site.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcutree.c | 25 +++----------------------
1 file changed, 3 insertions(+), 22 deletions(-)

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index ca07f2d..f6cf5e1 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1298,26 +1298,6 @@ static void note_gp_changes(struct rcu_state *rsp, struct rcu_data *rdp)
}

/*
- * Did someone else start a new RCU grace period start since we last
- * checked? Update local state appropriately if so. Must be called
- * on the CPU corresponding to rdp.
- */
-static int
-check_for_new_grace_period(struct rcu_state *rsp, struct rcu_data *rdp)
-{
- unsigned long flags;
- int ret = 0;
-
- local_irq_save(flags);
- if (rdp->gpnum != rsp->gpnum) {
- note_gp_changes(rsp, rdp);
- ret = 1;
- }
- local_irq_restore(flags);
- return ret;
-}
-
-/*
* Do per-CPU grace-period initialization for running CPU. The caller
* must hold the lock of the leaf rcu_node structure corresponding to
* this CPU.
@@ -1727,8 +1707,10 @@ static void
rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
{
/* If there is now a new grace period, record and return. */
- if (check_for_new_grace_period(rsp, rdp))
+ if (rdp->gpnum != rsp->gpnum) {
+ note_gp_changes(rsp, rdp);
return;
+ }

/*
* Does this CPU still need to do its part for current grace period?
@@ -2280,7 +2262,6 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp,

/* Are we ignoring a completed grace period? */
note_gp_changes(rsp, rdp);
- check_for_new_grace_period(rsp, rdp);

/* Start a new grace period if one not already started. */
if (!rcu_gp_in_progress(rsp)) {
--
1.8.1.5

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