Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:

 - Cure for not using zalloc in the first place, which leads to random
   crashes with CPUMASK_OFF_STACK.

 - Revert a user space visible change which broke udev

 - Add a missing cpu_online early return introduced by the new full
   dyntick conversions

 - Plug a long standing race in the timer wheel cpu hotplug code.
   Sigh...

 - Cleanup NOHZ per cpu data on cpu down to prevent stale data on cpu
   up.

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Revert ALWAYS_USE_PERSISTENT_CLOCK compile time optimizaitons
  timer: Don't reinitialize the cpu base lock during CPU_UP_PREPARE
  tick: Don't invoke tick_nohz_stop_sched_tick() if the cpu is offline
  tick: Cleanup NOHZ per cpu data on cpu down
  tick: Use zalloc_cpumask_var for allocating offstack cpumasks

7 files changed, 8 insertions, 19 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6a154a91c7e7..685692c94f05 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -108,7 +108,6 @@ config X86
         select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
         select GENERIC_TIME_VSYSCALL if X86_64
         select KTIME_SCALAR if X86_32
-        select ALWAYS_USE_PERSISTENT_CLOCK
         select GENERIC_STRNCPY_FROM_USER
         select GENERIC_STRNLEN_USER
         select HAVE_CONTEXT_TRACKING if X86_64
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 0c81915b1997..b9838130a7b0 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -20,7 +20,6 @@ if RTC_CLASS
 config RTC_HCTOSYS
         bool "Set system time from RTC on startup and resume"
         default y
-        depends on !ALWAYS_USE_PERSISTENT_CLOCK
         help
           If you say yes here, the system time (wall clock) will be set using
           the value read from a specified RTC device. This is useful to avoid
@@ -29,7 +28,6 @@ config RTC_HCTOSYS
 config RTC_SYSTOHC
         bool "Set the RTC time based on NTP synchronization"
         default y
-        depends on !ALWAYS_USE_PERSISTENT_CLOCK
         help
           If you say yes here, the system time (wall clock) will be stored
           in the RTC specified by RTC_HCTOSYS_DEVICE approximately every 11
diff --git a/include/linux/time.h b/include/linux/time.h
index 22d81b3c955b..d5d229b2e5af 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -117,14 +117,10 @@ static inline bool timespec_valid_strict(const struct timespec *ts)
 
 extern bool persistent_clock_exist;
 
-#ifdef ALWAYS_USE_PERSISTENT_CLOCK
-#define has_persistent_clock()  true
-#else
 static inline bool has_persistent_clock(void)
 {
         return persistent_clock_exist;
 }
-#endif
 
 extern void read_persistent_clock(struct timespec *ts);
 extern void read_boot_clock(struct timespec *ts);
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index e4c07b0692bb..70f27e89012b 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -12,11 +12,6 @@ config CLOCKSOURCE_WATCHDOG
 config ARCH_CLOCKSOURCE_DATA
         bool
 
-# Platforms has a persistent clock
-config ALWAYS_USE_PERSISTENT_CLOCK
-        bool
-        default n
-
 # Timekeeping vsyscall support
 config GENERIC_TIME_VSYSCALL
         bool
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 206bbfb34e09..24938d577669 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -786,11 +786,11 @@ bool tick_broadcast_oneshot_available(void)
 
 void __init tick_broadcast_init(void)
 {
-        alloc_cpumask_var(&tick_broadcast_mask, GFP_NOWAIT);
-        alloc_cpumask_var(&tmpmask, GFP_NOWAIT);
+        zalloc_cpumask_var(&tick_broadcast_mask, GFP_NOWAIT);
+        zalloc_cpumask_var(&tmpmask, GFP_NOWAIT);
 #ifdef CONFIG_TICK_ONESHOT
-        alloc_cpumask_var(&tick_broadcast_oneshot_mask, GFP_NOWAIT);
-        alloc_cpumask_var(&tick_broadcast_pending_mask, GFP_NOWAIT);
-        alloc_cpumask_var(&tick_broadcast_force_mask, GFP_NOWAIT);
+        zalloc_cpumask_var(&tick_broadcast_oneshot_mask, GFP_NOWAIT);
+        zalloc_cpumask_var(&tick_broadcast_pending_mask, GFP_NOWAIT);
+        zalloc_cpumask_var(&tick_broadcast_force_mask, GFP_NOWAIT);
 #endif
 }
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index bc67d4245e1d..f4208138fbf4 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -717,6 +717,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
         if (unlikely(!cpu_online(cpu))) {
                 if (cpu == tick_do_timer_cpu)
                         tick_do_timer_cpu = TICK_DO_TIMER_NONE;
+                return false;
         }
 
         if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
@@ -1168,7 +1169,7 @@ void tick_cancel_sched_timer(int cpu)
                 hrtimer_cancel(&ts->sched_timer);
 # endif
 
-        ts->nohz_mode = NOHZ_MODE_INACTIVE;
+        memset(ts, 0, sizeof(*ts));
 }
 #endif
 
diff --git a/kernel/timer.c b/kernel/timer.c
index a860bba34412..15ffdb3f1948 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1539,12 +1539,12 @@ static int __cpuinit init_timers_cpu(int cpu)
                         boot_done = 1;
                         base = &boot_tvec_bases;
                 }
+                spin_lock_init(&base->lock);
                 tvec_base_done[cpu] = 1;
         } else {
                 base = per_cpu(tvec_bases, cpu);
         }
 
-        spin_lock_init(&base->lock);
 
         for (j = 0; j < TVN_SIZE; j++) {
                 INIT_LIST_HEAD(base->tv5.vec + j);