[PATCH] nohz: Remove ts->inidle checks before restarting the tick

From: Frederic Weisbecker
Date: Tue Dec 06 2011 - 09:30:52 EST


ts->inidle is set by tick_nohz_stop_sched_tick(1) and unset
by tick_nohz_restart_sched_tick(). These two calls are assumed
to be always paired. This means that by the time we call
tick_nohz_restart_sched_tick(), ts->inidle is supposed to
be always set to 1.

Remove the checks for ts->inidle in tick_nohz_restart_sched_tick().
This simplifies a bit the code and improves its debuggability
(ie: ensure the call is paired with a tick_nohz_stop_sched_tick() call).

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
---
kernel/time/tick-sched.c | 12 +++++++-----
1 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 4042064..0f7c5e5 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -529,20 +529,22 @@ void tick_nohz_restart_sched_tick(void)
ktime_t now;

local_irq_disable();
- if (ts->idle_active || (ts->inidle && ts->tick_stopped))
+
+ WARN_ON_ONCE(!ts->inidle);
+
+ ts->inidle = 0;
+
+ if (ts->idle_active || ts->tick_stopped)
now = ktime_get();

if (ts->idle_active)
tick_nohz_stop_idle(cpu, now);

- if (!ts->inidle || !ts->tick_stopped) {
- ts->inidle = 0;
+ if (!ts->tick_stopped) {
local_irq_enable();
return;
}

- ts->inidle = 0;
-
rcu_exit_nohz();

/* Update jiffies first */
--
1.7.5.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/