linux-kernel - [PATCH 2/2] hrtimer: Unconfuse a bit switch_hrtimer

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Date:	Tue, 18 Aug 2015 16:18:29 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Thomas Gleixner <tglx@...utronix.de>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Frederic Weisbecker <fweisbec@...il.com>
Subject: [PATCH 2/2] hrtimer: Unconfuse a bit switch_hrtimer_base

The variable called "this_base" is confusing because its name suggests
it's of "struct hrtimer_clock_base" type, along with "base" and "new_base"
which doesn't help understanding this complicated function.

Make its name clearer and fix the misleading comments while at it.

Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
---
 kernel/time/hrtimer.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index f9eb21b..1828ed0 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -196,18 +196,20 @@ struct hrtimer_cpu_base *get_target_base(struct hrtimer_cpu_base *base,
 #endif
 
 /*
- * Switch the timer base to the current CPU when possible.
+ * Switch the timer base to a power-optimized selected CPU target.
+ * If that would involve clock reprogramming, which we can't do on a remote
+ * target, just switch to the current CPU.
  */
 static inline struct hrtimer_clock_base *
 switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base,
 		    int pinned)
 {
-	struct hrtimer_cpu_base *new_cpu_base, *this_base;
+	struct hrtimer_cpu_base *new_cpu_base, *this_cpu_base;
 	struct hrtimer_clock_base *new_base;
 	int basenum = base->index;
 
-	this_base = this_cpu_ptr(&hrtimer_bases);
-	new_cpu_base = get_target_base(this_base, pinned);
+	this_cpu_base = this_cpu_ptr(&hrtimer_bases);
+	new_cpu_base = get_target_base(this_cpu_base, pinned);
 again:
 	new_base = &new_cpu_base->clock_base[basenum];
 
@@ -229,19 +231,19 @@ again:
 		raw_spin_unlock(&base->cpu_base->lock);
 		raw_spin_lock(&new_base->cpu_base->lock);
 
-		if (new_cpu_base != this_base &&
+		if (new_cpu_base != this_cpu_base &&
 		    hrtimer_check_target(timer, new_base)) {
 			raw_spin_unlock(&new_base->cpu_base->lock);
 			raw_spin_lock(&base->cpu_base->lock);
-			new_cpu_base = this_base;
+			new_cpu_base = this_cpu_base;
 			timer->base = base;
 			goto again;
 		}
 		timer->base = new_base;
 	} else {
-		if (new_cpu_base != this_base &&
+		if (new_cpu_base != this_cpu_base &&
 		    hrtimer_check_target(timer, new_base)) {
-			new_cpu_base = this_base;
+			new_cpu_base = this_cpu_base;
 			goto again;
 		}
 	}
-- 
2.1.4

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