6 files changed, 36 insertions, 34 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 52075633373f..b766d28accd6 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -826,10 +826,9 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
         new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
 
         /*
-         * This happens when we have stolen the lock and the original
-         * pending owner did not enqueue itself back on the rt_mutex.
-         * Thats not a tragedy. We know that way, that a lock waiter
-         * is on the fly. We make the futex_q waiter the pending owner.
+         * It is possible that the next waiter (the one that brought
+         * this owner to the kernel) timed out and is no longer
+         * waiting on the lock.
          */
         if (!new_owner)
                 new_owner = this->task;
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index 034493724749..0c343b9a46d5 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -189,7 +189,8 @@ static int rcu_kthread(void *arg)
         unsigned long flags;
 
         for (;;) {
-                wait_event(rcu_kthread_wq, have_rcu_kthread_work != 0);
+                wait_event_interruptible(rcu_kthread_wq,
+                                         have_rcu_kthread_work != 0);
                 morework = rcu_boost();
                 local_irq_save(flags);
                 work = have_rcu_kthread_work;
diff --git a/kernel/srcu.c b/kernel/srcu.c
index 98d8c1e80edb..73ce23feaea9 100644
--- a/kernel/srcu.c
+++ b/kernel/srcu.c
@@ -156,6 +156,16 @@ void __srcu_read_unlock(struct srcu_struct *sp, int idx)
 EXPORT_SYMBOL_GPL(__srcu_read_unlock);
 
 /*
+ * We use an adaptive strategy for synchronize_srcu() and especially for
+ * synchronize_srcu_expedited().  We spin for a fixed time period
+ * (defined below) to allow SRCU readers to exit their read-side critical
+ * sections.  If there are still some readers after 10 microseconds,
+ * we repeatedly block for 1-millisecond time periods.  This approach
+ * has done well in testing, so there is no need for a config parameter.
+ */
+#define SYNCHRONIZE_SRCU_READER_DELAY 10
+
+/*
  * Helper function for synchronize_srcu() and synchronize_srcu_expedited().
  */
 static void __synchronize_srcu(struct srcu_struct *sp, void (*sync_func)(void))
@@ -207,11 +217,12 @@ static void __synchronize_srcu(struct srcu_struct *sp, void (*sync_func)(void))
          * will have finished executing.  We initially give readers
          * an arbitrarily chosen 10 microseconds to get out of their
          * SRCU read-side critical sections, then loop waiting 1/HZ
-         * seconds per iteration.
+         * seconds per iteration.  The 10-microsecond value has done
+         * very well in testing.
          */
 
         if (srcu_readers_active_idx(sp, idx))
-                udelay(CONFIG_SRCU_SYNCHRONIZE_DELAY);
+                udelay(SYNCHRONIZE_SRCU_READER_DELAY);
         while (srcu_readers_active_idx(sp, idx))
                 schedule_timeout_interruptible(1);
 
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index c50a034de30f..6519cf62d9cd 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -113,7 +113,7 @@ EXPORT_SYMBOL_GPL(timecounter_cyc2time);
  * @shift:      pointer to shift variable
  * @from:       frequency to convert from
  * @to:         frequency to convert to
- * @minsec:     guaranteed runtime conversion range in seconds
+ * @maxsec:     guaranteed runtime conversion range in seconds
  *
  * The function evaluates the shift/mult pair for the scaled math
  * operations of clocksources and clockevents.
@@ -122,7 +122,7 @@ EXPORT_SYMBOL_GPL(timecounter_cyc2time);
  * NSEC_PER_SEC == 1GHz and @from is the counter frequency. For clock
  * event @to is the counter frequency and @from is NSEC_PER_SEC.
  *
- * The @minsec conversion range argument controls the time frame in
+ * The @maxsec conversion range argument controls the time frame in
  * seconds which must be covered by the runtime conversion with the
  * calculated mult and shift factors. This guarantees that no 64bit
  * overflow happens when the input value of the conversion is
@@ -131,7 +131,7 @@ EXPORT_SYMBOL_GPL(timecounter_cyc2time);
  * factors.
  */
 void
-clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec)
+clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 maxsec)
 {
         u64 tmp;
         u32 sft, sftacc= 32;
@@ -140,7 +140,7 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec)
          * Calculate the shift factor which is limiting the conversion
          * range:
          */
-        tmp = ((u64)minsec * from) >> 32;
+        tmp = ((u64)maxsec * from) >> 32;
         while (tmp) {
                 tmp >>=1;
                 sftacc--;
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 5536aaf3ba36..d27c7562902c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -49,7 +49,7 @@ struct timekeeper {
         u32     mult;
 };
 
-struct timekeeper timekeeper;
+static struct timekeeper timekeeper;
 
 /**
  * timekeeper_setup_internals - Set up internals to use clocksource clock.
@@ -164,7 +164,7 @@ static struct timespec total_sleep_time;
 /*
  * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
  */
-struct timespec raw_time;
+static struct timespec raw_time;
 
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index bac752f0cfb5..b706529b4fc7 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -23,9 +23,6 @@ static int syscall_exit_register(struct ftrace_event_call *event,
 static int syscall_enter_define_fields(struct ftrace_event_call *call);
 static int syscall_exit_define_fields(struct ftrace_event_call *call);
 
-/* All syscall exit events have the same fields */
-static LIST_HEAD(syscall_exit_fields);
-
 static struct list_head *
 syscall_get_enter_fields(struct ftrace_event_call *call)
 {
@@ -34,34 +31,28 @@ syscall_get_enter_fields(struct ftrace_event_call *call)
         return &entry->enter_fields;
 }
 
-static struct list_head *
-syscall_get_exit_fields(struct ftrace_event_call *call)
-{
-        return &syscall_exit_fields;
-}
-
 struct trace_event_functions enter_syscall_print_funcs = {
-        .trace                  = print_syscall_enter,
+        .trace          = print_syscall_enter,
 };
 
 struct trace_event_functions exit_syscall_print_funcs = {
-        .trace                  = print_syscall_exit,
+        .trace          = print_syscall_exit,
 };
 
 struct ftrace_event_class event_class_syscall_enter = {
-        .system                 = "syscalls",
-        .reg                    = syscall_enter_register,
-        .define_fields          = syscall_enter_define_fields,
-        .get_fields             = syscall_get_enter_fields,
-        .raw_init               = init_syscall_trace,
+        .system         = "syscalls",
+        .reg            = syscall_enter_register,
+        .define_fields  = syscall_enter_define_fields,
+        .get_fields     = syscall_get_enter_fields,
+        .raw_init       = init_syscall_trace,
 };
 
 struct ftrace_event_class event_class_syscall_exit = {
-        .system                 = "syscalls",
-        .reg                    = syscall_exit_register,
-        .define_fields          = syscall_exit_define_fields,
-        .get_fields             = syscall_get_exit_fields,
-        .raw_init               = init_syscall_trace,
+        .system         = "syscalls",
+        .reg            = syscall_exit_register,
+        .define_fields  = syscall_exit_define_fields,
+        .fields         = LIST_HEAD_INIT(event_class_syscall_exit.fields),
+        .raw_init       = init_syscall_trace,
 };
 
 extern unsigned long __start_syscalls_metadata[];