96 lines
3.4 KiB
Diff
96 lines
3.4 KiB
Diff
From 3ab1275c2351556c9db507a4f9a0b60746eae84b Mon Sep 17 00:00:00 2001
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From: Thomas Gleixner <tglx@linutronix.de>
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Date: Fri, 24 Jun 2011 22:23:02 +0200
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Subject: [PATCH 067/286] rcu: Reduce lock section
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So the waitqueue wakeup is outside the raw locked section.
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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---
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kernel/rcutree.c | 2 +-
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kernel/rcutree.h | 3 ++-
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kernel/rcutree_plugin.h | 14 ++++++++------
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3 files changed, 11 insertions(+), 8 deletions(-)
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diff --git a/kernel/rcutree.c b/kernel/rcutree.c
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index 6b76d81..8ef8675 100644
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--- a/kernel/rcutree.c
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+++ b/kernel/rcutree.c
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@@ -1221,7 +1221,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
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else
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raw_spin_unlock_irqrestore(&rnp->lock, flags);
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if (need_report & RCU_OFL_TASKS_EXP_GP)
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- rcu_report_exp_rnp(rsp, rnp);
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+ rcu_report_exp_rnp(rsp, rnp, true);
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rcu_node_kthread_setaffinity(rnp, -1);
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}
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diff --git a/kernel/rcutree.h b/kernel/rcutree.h
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index 849ce9e..dca495d 100644
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--- a/kernel/rcutree.h
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+++ b/kernel/rcutree.h
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@@ -451,7 +451,8 @@ static void rcu_preempt_check_callbacks(int cpu);
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static void rcu_preempt_process_callbacks(void);
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void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
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#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_TREE_PREEMPT_RCU)
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-static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp);
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+static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
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+ bool wake);
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#endif /* #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_TREE_PREEMPT_RCU) */
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static int rcu_preempt_pending(int cpu);
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static int rcu_preempt_needs_cpu(int cpu);
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diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
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index 4b9b9f8..73cab33 100644
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--- a/kernel/rcutree_plugin.h
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+++ b/kernel/rcutree_plugin.h
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@@ -407,7 +407,7 @@ static noinline void rcu_read_unlock_special(struct task_struct *t)
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* then we need to report up the rcu_node hierarchy.
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*/
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if (!empty_exp && !rcu_preempted_readers_exp(rnp))
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- rcu_report_exp_rnp(&rcu_preempt_state, rnp);
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+ rcu_report_exp_rnp(&rcu_preempt_state, rnp, true);
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} else {
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local_irq_restore(flags);
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}
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@@ -731,7 +731,8 @@ static int sync_rcu_preempt_exp_done(struct rcu_node *rnp)
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*
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* Caller must hold sync_rcu_preempt_exp_mutex.
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*/
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-static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp)
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+static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
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+ bool wake)
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{
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unsigned long flags;
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unsigned long mask;
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@@ -744,7 +745,8 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp)
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}
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if (rnp->parent == NULL) {
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raw_spin_unlock_irqrestore(&rnp->lock, flags);
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- wake_up(&sync_rcu_preempt_exp_wq);
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+ if (wake)
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+ wake_up(&sync_rcu_preempt_exp_wq);
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break;
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}
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mask = rnp->grpmask;
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@@ -777,7 +779,7 @@ sync_rcu_preempt_exp_init(struct rcu_state *rsp, struct rcu_node *rnp)
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must_wait = 1;
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}
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if (!must_wait)
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- rcu_report_exp_rnp(rsp, rnp);
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+ rcu_report_exp_rnp(rsp, rnp, false);
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}
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/*
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@@ -1069,9 +1071,9 @@ EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);
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* report on tasks preempted in RCU read-side critical sections during
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* expedited RCU grace periods.
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*/
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-static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp)
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+static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
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+ bool wake)
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{
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- return;
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}
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#endif /* #ifdef CONFIG_HOTPLUG_CPU */
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