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>

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>
Frederic Weisbecker
1 parent 33a5f6261a
Showing 3 changed files with 19 additions and 1 deletions Side-by-side Diff
include/linux/irq_work.h
kernel/irq_work.c
kernel/time/tick-sched.c
@@ -20,5 +20,11 @@
 void irq_work_run(void);
 void irq_work_sync(struct irq_work *work);
  
+#ifdef CONFIG_IRQ_WORK
+bool irq_work_needs_cpu(void);
+#else
+static bool irq_work_needs_cpu(void) { return false; }
+#endif
+
 #endif /* _LINUX_IRQ_WORK_H */
@@ -99,6 +99,17 @@
 }
 EXPORT_SYMBOL_GPL(irq_work_queue);
  
+bool irq_work_needs_cpu(void)
+{
+	struct llist_head *this_list;
+
+	this_list = &__get_cpu_var(irq_work_list);
+	if (llist_empty(this_list))
+		return false;
+
+	return true;
+}
+
 /*
  * Run the irq_work entries on this cpu. Requires to be ran from hardirq
  * context with local IRQs disabled.
@@ -20,6 +20,7 @@
 #include <linux/profile.h>
 #include <linux/sched.h>
 #include <linux/module.h>
+#include <linux/irq_work.h>
  
 #include <asm/irq_regs.h>
  
@@ -289,7 +290,7 @@
 	} while (read_seqretry(&xtime_lock, seq));
  
 	if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || printk_needs_cpu(cpu) ||
-	    arch_needs_cpu(cpu)) {
+	    arch_needs_cpu(cpu) || irq_work_needs_cpu()) {
 		next_jiffies = last_jiffies + 1;
 		delta_jiffies = 1;
 	} else {
...	...	@@ -20,5 +20,11 @@
20	20	void irq_work_run(void);
21	21	void irq_work_sync(struct irq_work *work);
22	22
	23	+#ifdef CONFIG_IRQ_WORK
	24	+bool irq_work_needs_cpu(void);
	25	+#else
	26	+static bool irq_work_needs_cpu(void) { return false; }
	27	+#endif
	28	+
23	29	#endif /* _LINUX_IRQ_WORK_H */
...	...	@@ -99,6 +99,17 @@
99	99	}
100	100	EXPORT_SYMBOL_GPL(irq_work_queue);
101	101
	102	+bool 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	114	* Run the irq_work entries on this cpu. Requires to be ran from hardirq
104	115	* context with local IRQs disabled.
...	...	@@ -20,6 +20,7 @@
20	20	#include <linux/profile.h>
21	21	#include <linux/sched.h>
22	22	#include <linux/module.h>
	23	+#include <linux/irq_work.h>
23	24
24	25	#include <asm/irq_regs.h>
25	26
...	...	@@ -289,7 +290,7 @@
289	290	} while (read_seqretry(&xtime_lock, seq));
290	291
291	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	294	next_jiffies = last_jiffies + 1;
294	295	delta_jiffies = 1;
295	296	} else {