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

Pull core kernel fixes from Ingo Molnar:
 "This contains the nohz/atomic cleanup/fix for the fetch_or() ugliness
  you noted during the original nohz pull request, plus there's also
  misc fixes:

   - fix liblockdep build bug
   - fix uapi header build bug
   - print more lockdep hash collision info to help debug recent reports
     of hash collisions
   - update MAINTAINERS email address"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Update my email address
  locking/lockdep: Print chain_key collision information
  uapi/linux/stddef.h: Provide __always_inline to userspace headers
  tools/lib/lockdep: Fix unsupported 'basename -s' in run_tests.sh
  locking/atomic, sched: Unexport fetch_or()
  timers/nohz: Convert tick dependency mask to atomic_t
  locking/atomic: Introduce atomic_fetch_or()

1 files changed, 30 insertions, 31 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 084b79f5917e..58e3310c9b21 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -157,52 +157,50 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs)
 cpumask_var_t tick_nohz_full_mask;
 cpumask_var_t housekeeping_mask;
 bool tick_nohz_full_running;
-static unsigned long tick_dep_mask;
+static atomic_t tick_dep_mask;
 
-static void trace_tick_dependency(unsigned long dep)
+static bool check_tick_dependency(atomic_t *dep)
 {
-	if (dep & TICK_DEP_MASK_POSIX_TIMER) {
+	int val = atomic_read(dep);
+
+	if (val & TICK_DEP_MASK_POSIX_TIMER) {
 		trace_tick_stop(0, TICK_DEP_MASK_POSIX_TIMER);
-		return;
+		return true;
 	}
 
-	if (dep & TICK_DEP_MASK_PERF_EVENTS) {
+	if (val & TICK_DEP_MASK_PERF_EVENTS) {
 		trace_tick_stop(0, TICK_DEP_MASK_PERF_EVENTS);
-		return;
+		return true;
 	}
 
-	if (dep & TICK_DEP_MASK_SCHED) {
+	if (val & TICK_DEP_MASK_SCHED) {
 		trace_tick_stop(0, TICK_DEP_MASK_SCHED);
-		return;
+		return true;
 	}
 
-	if (dep & TICK_DEP_MASK_CLOCK_UNSTABLE)
+	if (val & TICK_DEP_MASK_CLOCK_UNSTABLE) {
 		trace_tick_stop(0, TICK_DEP_MASK_CLOCK_UNSTABLE);
+		return true;
+	}
+
+	return false;
 }
 
 static bool can_stop_full_tick(struct tick_sched *ts)
 {
 	WARN_ON_ONCE(!irqs_disabled());
 
-	if (tick_dep_mask) {
-		trace_tick_dependency(tick_dep_mask);
+	if (check_tick_dependency(&tick_dep_mask))
 		return false;
-	}
 
-	if (ts->tick_dep_mask) {
-		trace_tick_dependency(ts->tick_dep_mask);
+	if (check_tick_dependency(&ts->tick_dep_mask))
 		return false;
-	}
 
-	if (current->tick_dep_mask) {
-		trace_tick_dependency(current->tick_dep_mask);
+	if (check_tick_dependency(&current->tick_dep_mask))
 		return false;
-	}
 
-	if (current->signal->tick_dep_mask) {
-		trace_tick_dependency(current->signal->tick_dep_mask);
+	if (check_tick_dependency(&current->signal->tick_dep_mask))
 		return false;
-	}
 
 	return true;
 }
@@ -259,12 +257,12 @@ static void tick_nohz_full_kick_all(void)
 	preempt_enable();
 }
 
-static void tick_nohz_dep_set_all(unsigned long *dep,
+static void tick_nohz_dep_set_all(atomic_t *dep,
 				  enum tick_dep_bits bit)
 {
-	unsigned long prev;
+	int prev;
 
-	prev = fetch_or(dep, BIT_MASK(bit));
+	prev = atomic_fetch_or(dep, BIT(bit));
 	if (!prev)
 		tick_nohz_full_kick_all();
 }
@@ -280,7 +278,7 @@ void tick_nohz_dep_set(enum tick_dep_bits bit)
 
 void tick_nohz_dep_clear(enum tick_dep_bits bit)
 {
-	clear_bit(bit, &tick_dep_mask);
+	atomic_andnot(BIT(bit), &tick_dep_mask);
 }
 
 /*
@@ -289,12 +287,12 @@ void tick_nohz_dep_clear(enum tick_dep_bits bit)
  */
 void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit)
 {
-	unsigned long prev;
+	int prev;
 	struct tick_sched *ts;
 
 	ts = per_cpu_ptr(&tick_cpu_sched, cpu);
 
-	prev = fetch_or(&ts->tick_dep_mask, BIT_MASK(bit));
+	prev = atomic_fetch_or(&ts->tick_dep_mask, BIT(bit));
 	if (!prev) {
 		preempt_disable();
 		/* Perf needs local kick that is NMI safe */
@@ -313,7 +311,7 @@ void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit)
 {
 	struct tick_sched *ts = per_cpu_ptr(&tick_cpu_sched, cpu);
 
-	clear_bit(bit, &ts->tick_dep_mask);
+	atomic_andnot(BIT(bit), &ts->tick_dep_mask);
 }
 
 /*
@@ -331,7 +329,7 @@ void tick_nohz_dep_set_task(struct task_struct *tsk, enum tick_dep_bits bit)
 
 void tick_nohz_dep_clear_task(struct task_struct *tsk, enum tick_dep_bits bit)
 {
-	clear_bit(bit, &tsk->tick_dep_mask);
+	atomic_andnot(BIT(bit), &tsk->tick_dep_mask);
 }
 
 /*
@@ -345,7 +343,7 @@ void tick_nohz_dep_set_signal(struct signal_struct *sig, enum tick_dep_bits bit)
 
 void tick_nohz_dep_clear_signal(struct signal_struct *sig, enum tick_dep_bits bit)
 {
-	clear_bit(bit, &sig->tick_dep_mask);
+	atomic_andnot(BIT(bit), &sig->tick_dep_mask);
 }
 
 /*
@@ -366,7 +364,8 @@ void __tick_nohz_task_switch(void)
 	ts = this_cpu_ptr(&tick_cpu_sched);
 
 	if (ts->tick_stopped) {
-		if (current->tick_dep_mask || current->signal->tick_dep_mask)
+		if (atomic_read(&current->tick_dep_mask) ||
+		    atomic_read(&current->signal->tick_dep_mask))
 			tick_nohz_full_kick();
 	}
 out: