Commit 00b42959 authored by Frederic Weisbecker's avatar Frederic Weisbecker
Browse files

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: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: default avatarSteven 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>
parent 33a5f626

include/linux/irq_work.h

+6 −0
Original line number Diff line number Diff line
@@ -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 */

kernel/irq_work.c

+11 −0
Original line number Diff line number Diff line
@@ -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.

kernel/time/tick-sched.c

+2 −1
Original line number Diff line number Diff line
@@ -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 {

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