srcu: Introduce srcu_gp_is_expedited() helper function

Even though the open-coded expressions usually fit on one line, this
commit replaces them with a call to a new srcu_gp_is_expedited()
helper function in order to improve readability.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: <bpf@vger.kernel.org>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>

diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 2fe0abade9c06ca19bf5fe34c41198cbea52c6cd..5b1a315f77bc62f6b201c2ef8f9de6d0dcc57d1f 100644 (file)
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -418,6 +418,16 @@ static void check_init_srcu_struct(struct srcu_struct *ssp)
        spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
 }
 
+/*
+ * Is the current or any upcoming grace period to be expedited?
+ */
+static bool srcu_gp_is_expedited(struct srcu_struct *ssp)
+{
+       struct srcu_usage *sup = ssp->srcu_sup;
+
+       return ULONG_CMP_LT(READ_ONCE(sup->srcu_gp_seq), READ_ONCE(sup->srcu_gp_seq_needed_exp));
+}
+
 /*
  * Returns approximate total of the readers' ->srcu_lock_count[] values
  * for the rank of per-CPU counters specified by idx.
@@ -622,7 +632,7 @@ static unsigned long srcu_get_delay(struct srcu_struct *ssp)
        unsigned long jbase = SRCU_INTERVAL;
        struct srcu_usage *sup = ssp->srcu_sup;
 
-       if (ULONG_CMP_LT(READ_ONCE(sup->srcu_gp_seq), READ_ONCE(sup->srcu_gp_seq_needed_exp)))
+       if (srcu_gp_is_expedited(ssp))
                jbase = 0;
        if (rcu_seq_state(READ_ONCE(sup->srcu_gp_seq))) {
                j = jiffies - 1;
@@ -867,7 +877,7 @@ static void srcu_gp_end(struct srcu_struct *ssp)
        spin_lock_irq_rcu_node(sup);
        idx = rcu_seq_state(sup->srcu_gp_seq);
        WARN_ON_ONCE(idx != SRCU_STATE_SCAN2);
-       if (ULONG_CMP_LT(READ_ONCE(sup->srcu_gp_seq), READ_ONCE(sup->srcu_gp_seq_needed_exp)))
+       if (srcu_gp_is_expedited(ssp))
                cbdelay = 0;
 
        WRITE_ONCE(sup->srcu_last_gp_end, ktime_get_mono_fast_ns());