linux-kernel - [PATCH 23/38] tick-sched: invert parameter of tick_check_oneshot

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Message-Id: <b77b07b9ec33231122c90e3888b7dda05e4aef9c.1397492345.git.viresh.kumar@linaro.org>
Date:	Mon, 14 Apr 2014 21:53:45 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	tglx@...utronix.de
Cc:	linaro-kernel@...ts.linaro.org, linux-kernel@...r.kernel.org,
	fweisbec@...il.com, Arvind.Chauhan@....com,
	linaro-networking@...aro.org,
	Viresh Kumar <viresh.kumar@...aro.org>
Subject: [PATCH 23/38] tick-sched: invert parameter of tick_check_oneshot_change()

There is only one caller of tick_check_oneshot_change(), i.e.
hrtimer_run_pending(). Firstly hrtimer_run_pending() is calling this routine
after doing a '!' of its parameter and then tick_check_oneshot_change() is also
using it after doing a '!' of its parameter.

It would be more efficient and readable if we can just invert the meaning of
this parameter. So, it is hres_enabled instead of allow_nohz now.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 include/linux/tick.h     |  6 +++---
 kernel/hrtimer.c         |  2 +-
 kernel/time/tick-sched.c | 10 +++++-----
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/tick.h b/include/linux/tick.h
index b8ee6f4..801e844 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -120,7 +120,7 @@ extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
 
 # ifdef CONFIG_TICK_ONESHOT
 extern void tick_clock_notify(void);
-extern int tick_check_oneshot_change(int allow_nohz);
+extern int tick_check_oneshot_change(int hres_enabled);
 extern struct tick_sched *tick_get_tick_sched(int cpu);
 extern void tick_irq_enter(void);
 extern int tick_oneshot_mode_active(void);
@@ -129,7 +129,7 @@ extern int tick_oneshot_mode_active(void);
 #  endif
 # else
 static inline void tick_clock_notify(void) { }
-static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
+static inline int tick_check_oneshot_change(int hres_enabled) { return 0; }
 static inline void tick_irq_enter(void) { }
 static inline int tick_oneshot_mode_active(void) { return 0; }
 # endif
@@ -138,7 +138,7 @@ static inline int tick_oneshot_mode_active(void) { return 0; }
 static inline void tick_init(void) { }
 static inline void tick_cancel_sched_timer(int cpu) { }
 static inline void tick_clock_notify(void) { }
-static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
+static inline int tick_check_oneshot_change(int hres_enabled) { return 0; }
 static inline void tick_irq_enter(void) { }
 static inline int tick_oneshot_mode_active(void) { return 0; }
 #endif /* !CONFIG_GENERIC_CLOCKEVENTS */
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 393f422..bfa7811 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1457,7 +1457,7 @@ void hrtimer_run_pending(void)
 	 * check bit in the tick_oneshot code, otherwise we might
 	 * deadlock vs. xtime_lock.
 	 */
-	if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
+	if (tick_check_oneshot_change(hrtimer_is_hres_enabled()))
 		hrtimer_switch_to_hres();
 }
 
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index c81b6cf..256f4a3 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1177,11 +1177,11 @@ void tick_oneshot_notify(void)
  * Check, if a change happened, which makes oneshot possible.
  *
  * Called cyclic from the hrtimer softirq (driven by the timer
- * softirq) allow_nohz signals, that we can switch into low-res nohz
- * mode, because high resolution timers are disabled (either compile
- * or runtime).
+ * softirq). If hres_enabled is non zero, it means we can't switch into low-res
+ * nohz mode, because high resolution timers are enabled(either compile or
+ * runtime).
  */
-int tick_check_oneshot_change(int allow_nohz)
+int tick_check_oneshot_change(int hres_enabled)
 {
 	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
 
@@ -1194,7 +1194,7 @@ int tick_check_oneshot_change(int allow_nohz)
 	if (!timekeeping_valid_for_hres() || !tick_is_oneshot_available())
 		return 0;
 
-	if (!allow_nohz)
+	if (hres_enabled)
 		return 1;
 
 	tick_nohz_switch_to_nohz();
-- 
1.7.12.rc2.18.g61b472e

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