The patch titled
time: optimise tick_nohz_stop_sched_tick() a bit
has been added to the -mm tree. Its filename is
optimise-tick_nohz_stop_sched_tick-a-bit.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: time: optimise tick_nohz_stop_sched_tick() a bit
From: Karsten Wiese <fzu@xxxxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/time/tick-sched.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff -puN kernel/time/tick-sched.c~optimise-tick_nohz_stop_sched_tick-a-bit kernel/time/tick-sched.c
--- a/kernel/time/tick-sched.c~optimise-tick_nohz_stop_sched_tick-a-bit
+++ a/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();
@@ -200,8 +199,8 @@ 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
@@ -221,7 +220,6 @@ void tick_nohz_stop_sched_tick(void)
if (need_resched())
goto end;
- cpu = smp_processor_id();
if (unlikely(local_softirq_pending())) {
static int ratelimit;
_
Patches currently in -mm which might be from fzu@xxxxxxxxxxxxxxxxxxxxx are
time-dont-touch-an-offlined-cpus-ts-tick_stopped-in-tick_cancel_sched_timer.patch
optimise-tick_nohz_stop_sched_tick-a-bit.patch
optimise-tick_nohz_stop_sched_tick-a-bit-fix.patch
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