nohz: disable tick_nohz_kick_tick() for now
Impact: nohz powersavings and wakeup regression
commit fb02fbc14d17837b4b7b02dbb36142c16a7bf208 (NOHZ: restart tick
device from irq_enter()) causes a serious wakeup regression.
While the patch is correct it does not take into account that spurious
wakeups happen on x86. A fix for this issue is available, but we just
revert to the .27 behaviour and let long running softirqs screw
themself.
Disable it for now.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 5bbb104..342fc9c 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -568,6 +568,9 @@
*/
static void tick_nohz_kick_tick(int cpu)
{
+#if 0
+ /* Switch back to 2.6.27 behaviour */
+
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
ktime_t delta, now;
@@ -584,6 +587,7 @@
return;
tick_nohz_restart(ts, now);
+#endif
}
#else