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Message-Id: <1352380498-23132-6-git-send-email-fweisbec@gmail.com>
Date: Thu, 8 Nov 2012 14:14:56 +0100
From: Frederic Weisbecker <fweisbec@...il.com>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Frederic Weisbecker <fweisbec@...il.com>,
Peter Zijlstra <peterz@...radead.org>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...nel.org>,
Andrew Morton <akpm@...ux-foundation.org>,
Steven Rostedt <rostedt@...dmis.org>,
Paul Gortmaker <paul.gortmaker@...driver.com>
Subject: [PATCH 5/7] 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@...il.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Steven Rostedt <rostedt@...dmis.org>
Cc: Paul Gortmaker <paul.gortmaker@...driver.com>
---
include/linux/irq_work.h | 6 ++++++
kernel/irq_work.c | 11 +++++++++++
kernel/time/tick-sched.c | 3 ++-
3 files changed, 19 insertions(+), 1 deletions(-)
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 6a9e8f5..a69704f 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);
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 */
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 64eddd5..b3c113a 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -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.
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 9e945aa..f249e8c 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -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 {
--
1.7.5.4
--
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