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authorFrederic Weisbecker <fweisbec@gmail.com>2012-11-07 15:03:07 -0500
committerFrederic Weisbecker <fweisbec@gmail.com>2012-11-17 13:30:39 -0500
commit00b42959106a9ca1c2899e591ae4e9a83ad6af05 (patch)
tree7dd755a813fe7a7fe635082fc5010eb73725f2fe
parent33a5f6261a61af28f7b4c86f9f958da0f206c914 (diff)
irq_work: Don't stop the tick with pending works
Don't stop the tick if we have pending irq works on the queue, otherwise if the arch can't raise self-IPIs, we may not find an opportunity to execute the pending works for a while. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
-rw-r--r--include/linux/irq_work.h6
-rw-r--r--kernel/irq_work.c11
-rw-r--r--kernel/time/tick-sched.c3
3 files changed, 19 insertions, 1 deletions
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 6a9e8f5399e2..a69704f37204 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -20,4 +20,10 @@ bool irq_work_queue(struct irq_work *work);
20void irq_work_run(void); 20void irq_work_run(void);
21void irq_work_sync(struct irq_work *work); 21void irq_work_sync(struct irq_work *work);
22 22
23#ifdef CONFIG_IRQ_WORK
24bool irq_work_needs_cpu(void);
25#else
26static bool irq_work_needs_cpu(void) { return false; }
27#endif
28
23#endif /* _LINUX_IRQ_WORK_H */ 29#endif /* _LINUX_IRQ_WORK_H */
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 64eddd59ed83..b3c113a14727 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -99,6 +99,17 @@ bool irq_work_queue(struct irq_work *work)
99} 99}
100EXPORT_SYMBOL_GPL(irq_work_queue); 100EXPORT_SYMBOL_GPL(irq_work_queue);
101 101
102bool irq_work_needs_cpu(void)
103{
104 struct llist_head *this_list;
105
106 this_list = &__get_cpu_var(irq_work_list);
107 if (llist_empty(this_list))
108 return false;
109
110 return true;
111}
112
102/* 113/*
103 * Run the irq_work entries on this cpu. Requires to be ran from hardirq 114 * Run the irq_work entries on this cpu. Requires to be ran from hardirq
104 * context with local IRQs disabled. 115 * context with local IRQs disabled.
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 9e945aa090ac..f249e8c3e58e 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -20,6 +20,7 @@
20#include <linux/profile.h> 20#include <linux/profile.h>
21#include <linux/sched.h> 21#include <linux/sched.h>
22#include <linux/module.h> 22#include <linux/module.h>
23#include <linux/irq_work.h>
23 24
24#include <asm/irq_regs.h> 25#include <asm/irq_regs.h>
25 26
@@ -289,7 +290,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
289 } while (read_seqretry(&xtime_lock, seq)); 290 } while (read_seqretry(&xtime_lock, seq));
290 291
291 if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || printk_needs_cpu(cpu) || 292 if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || printk_needs_cpu(cpu) ||
292 arch_needs_cpu(cpu)) { 293 arch_needs_cpu(cpu) || irq_work_needs_cpu()) {
293 next_jiffies = last_jiffies + 1; 294 next_jiffies = last_jiffies + 1;
294 delta_jiffies = 1; 295 delta_jiffies = 1;
295 } else { 296 } else {