From: Karsten Wiese <fzu@wemgehoertderstaat.de>
To: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>
Subject: [PATCH] Optimise tick_nohz_stop_sched_tick() a bit
Date: Thu, 28 Feb 2008 15:10:50 +0100 [thread overview]
Message-ID: <200802281510.51191.fzu@wemgehoertderstaat.de> (raw)
Call
ts = &per_cpu(tick_cpu_sched, cpu);
and
cpu = smp_processor_id();
once instead of twice.
No functional change done, as changed code runs with local irq off.
Reduces source lines and text size (20bytes on x86_64).
Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
---
kernel/time/tick-sched.c | 6 ++----
1 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 686da82..851a852 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -158,9 +158,8 @@ void tick_nohz_stop_idle(int cpu)
}
}
-static ktime_t tick_nohz_start_idle(int cpu)
+static ktime_t tick_nohz_start_idle(int cpu, struct tick_sched *ts)
{
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
ktime_t now, delta;
now = ktime_get();
@@ -201,8 +200,8 @@ void tick_nohz_stop_sched_tick(void)
local_irq_save(flags);
cpu = smp_processor_id();
- now = tick_nohz_start_idle(cpu);
ts = &per_cpu(tick_cpu_sched, cpu);
+ now = tick_nohz_start_idle(cpu, ts);
/*
* If this cpu is offline and it is the one which updates
@@ -222,7 +221,6 @@ void tick_nohz_stop_sched_tick(void)
if (need_resched())
goto end;
- cpu = smp_processor_id();
if (unlikely(local_softirq_pending())) {
static int ratelimit;
--
1.5.3.3
next reply other threads:[~2008-02-28 14:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-28 14:10 Karsten Wiese [this message]
2008-02-29 1:16 ` Andrew Morton
2008-02-29 15:57 ` Thomas Gleixner
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