The check for irqs_were_disabled is redundant in rcu_unlock_needs_exp_handling() as the caller already checks for this. This includes the boost case as well. Just remove the redundant check.
This is a first win for the refactor of the needs_exp (formerly expboost) condition into a new rcu_unlock_needs_exp_handling() function, as the conditions became more easier to read. Signed-off-by: Joel Fernandes <[email protected]> --- kernel/rcu/tree_plugin.h | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 8504d95bb35b..112973ecebb8 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -659,14 +659,12 @@ static void rcu_preempt_deferred_qs_handler(struct irq_work *iwp) * @t: The task being checked * @rdp: The per-CPU RCU data * @rnp: The RCU node for this CPU - * @irqs_were_disabled: Whether interrupts were disabled before rcu_read_unlock() * * Returns true if expedited processing of the rcu_read_unlock() is needed. */ static bool rcu_unlock_needs_exp_handling(struct task_struct *t, struct rcu_data *rdp, - struct rcu_node *rnp, - bool irqs_were_disabled) + struct rcu_node *rnp) { /* * Check if this task is blocking an expedited grace period. @@ -692,7 +690,7 @@ static bool rcu_unlock_needs_exp_handling(struct task_struct *t, * disturbing the system more. Check if either: * - This CPU has not yet reported a quiescent state, or * - This task was preempted within an RCU critical section - * In either case, requird expedited handling for strict GP mode. + * In either case, require expedited handling for strict GP mode. */ if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) && ((rdp->grpmask & READ_ONCE(rnp->qsmask)) || t->rcu_blocked_node)) @@ -700,14 +698,14 @@ static bool rcu_unlock_needs_exp_handling(struct task_struct *t, /* * RCU priority boosting case: If a task is subject to RCU priority - * boosting and exits an RCU read-side critical section with interrupts - * disabled, we need expedited handling to ensure timely deboosting. - * Without this, a low-priority task could incorrectly run at high - * real-time priority for an extended period effecting real-time - * responsiveness. This applies to all CONFIG_RCU_BOOST=y kernels, - * not just PREEMPT_RT. + * boosting and exits an RCU read-side critical section, we need + * expedited handling to ensure timely deboosting. Without this, + * a low-priority task could incorrectly run at high real-time + * priority for an extended period effecting real-time + * responsiveness. This applies to all RCU_BOOST=y kernels, + * not just to PREEMPT_RT. */ - if (IS_ENABLED(CONFIG_RCU_BOOST) && irqs_were_disabled && t->rcu_blocked_node) + if (IS_ENABLED(CONFIG_RCU_BOOST) && t->rcu_blocked_node) return true; return false; @@ -736,7 +734,7 @@ static void rcu_read_unlock_special(struct task_struct *t) struct rcu_data *rdp = this_cpu_ptr(&rcu_data); struct rcu_node *rnp = rdp->mynode; - needs_exp = rcu_unlock_needs_exp_handling(t, rdp, rnp, irqs_were_disabled); + needs_exp = rcu_unlock_needs_exp_handling(t, rdp, rnp); // Need to defer quiescent state until everything is enabled. if (use_softirq && (in_hardirq() || (needs_exp && !irqs_were_disabled))) { -- 2.43.0
