From 9424b867a759febc2b67b6777bfa27f0f830d437 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 22 Jul 2021 16:47:42 -0700 Subject: [PATCH] rcu: Eliminate rcu_implicit_dynticks_qs() local variable ruqp The rcu_implicit_dynticks_qs() function's local variable ruqp references the ->rcu_urgent_qs field in the rcu_data structure referenced by the function parameter rdp, with a rather odd method for computing the pointer to this field. This commit therefore simplifies things and saves a couple of lines of code by replacing each instance of ruqp with &rdp->need_heavy_qs. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 18d2f35..0bfebec 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1219,7 +1219,6 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp) static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) { unsigned long jtsq; - bool *ruqp; struct rcu_node *rnp = rdp->mynode; /* @@ -1284,16 +1283,15 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) * is set way high. */ jtsq = READ_ONCE(jiffies_to_sched_qs); - ruqp = per_cpu_ptr(&rcu_data.rcu_urgent_qs, rdp->cpu); if (!READ_ONCE(rdp->rcu_need_heavy_qs) && (time_after(jiffies, rcu_state.gp_start + jtsq * 2) || time_after(jiffies, rcu_state.jiffies_resched) || rcu_state.cbovld)) { WRITE_ONCE(rdp->rcu_need_heavy_qs, true); /* Store rcu_need_heavy_qs before rcu_urgent_qs. */ - smp_store_release(ruqp, true); + smp_store_release(&rdp->rcu_urgent_qs, true); } else if (time_after(jiffies, rcu_state.gp_start + jtsq)) { - WRITE_ONCE(*ruqp, true); + WRITE_ONCE(rdp->rcu_urgent_qs, true); } /* @@ -1307,7 +1305,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) if (tick_nohz_full_cpu(rdp->cpu) && (time_after(jiffies, READ_ONCE(rdp->last_fqs_resched) + jtsq * 3) || rcu_state.cbovld)) { - WRITE_ONCE(*ruqp, true); + WRITE_ONCE(rdp->rcu_urgent_qs, true); resched_cpu(rdp->cpu); WRITE_ONCE(rdp->last_fqs_resched, jiffies); } -- 2.7.4