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authorThomas Gleixner <tglx@linutronix.de>2008-11-10 13:20:23 +0100
committerThomas Gleixner <tglx@apollo.(none)>2008-11-10 22:39:27 +0100
commitae99286b4f1be7788f2d6947c66a91dbd6351eec (patch)
treea403ffaeaad1cb38afa79e2cca40ecc00ea694ab
parentee5f80a993539490a07477ff2526bf62c503fbb4 (diff)
downloadop-kernel-dev-ae99286b4f1be7788f2d6947c66a91dbd6351eec.zip
op-kernel-dev-ae99286b4f1be7788f2d6947c66a91dbd6351eec.tar.gz
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>
-rw-r--r--kernel/time/tick-sched.c4
1 files changed, 4 insertions, 0 deletions
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_switch_to_nohz(void)
*/
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 @@ static void tick_nohz_kick_tick(int cpu)
return;
tick_nohz_restart(ts, now);
+#endif
}
#else
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