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>
This commit is contained in:
Frederic Weisbecker 2012-11-07 21:03:07 +01:00
parent 33a5f6261a
commit 00b4295910
3 changed files with 19 additions and 1 deletions

View file

@ -20,4 +20,10 @@ bool irq_work_queue(struct irq_work *work);
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 */

View file

@ -99,6 +99,17 @@ bool irq_work_queue(struct irq_work *work)
}
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.

View file

@ -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 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
} 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 {