7 files changed, 18 insertions, 5 deletions

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 3c2d4972d235..de407c78178d 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -741,7 +741,7 @@ static struct console kgdbcons = {
 };
 
 #ifdef CONFIG_MAGIC_SYSRQ
-static void sysrq_handle_dbg(int key, struct tty_struct *tty)
+static void sysrq_handle_dbg(int key)
 {
         if (!dbg_io_ops) {
                 printk(KERN_CRIT "ERROR: No KGDB I/O module available\n");
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 28b844118bbd..caf057a3de0e 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1929,7 +1929,7 @@ static int kdb_sr(int argc, const char **argv)
         if (argc != 1)
                 return KDB_ARGCOUNT;
         kdb_trap_printk++;
-        __handle_sysrq(*argv[1], NULL, 0);
+        __handle_sysrq(*argv[1], false);
         kdb_trap_printk--;
 
         return 0;
diff --git a/kernel/power/poweroff.c b/kernel/power/poweroff.c
index e8b337006276..d52359374e85 100644
--- a/kernel/power/poweroff.c
+++ b/kernel/power/poweroff.c
@@ -24,7 +24,7 @@ static void do_poweroff(struct work_struct *dummy)
 
 static DECLARE_WORK(poweroff_work, do_poweroff);
 
-static void handle_poweroff(int key, struct tty_struct *tty)
+static void handle_poweroff(int key)
 {
         /* run sysrq poweroff on boot cpu */
         schedule_work_on(cpumask_first(cpu_online_mask), &poweroff_work);
diff --git a/kernel/sched.c b/kernel/sched.c
index 41541d79e3c8..09b574e7f4df 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3865,8 +3865,16 @@ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
                 /*
                  * Owner changed, break to re-assess state.
                  */
-                if (lock->owner != owner)
+                if (lock->owner != owner) {
+                        /*
+                         * If the lock has switched to a different owner,
+                         * we likely have heavy contention. Return 0 to quit
+                         * optimistic spinning and not contend further:
+                         */
+                        if (lock->owner)
+                                return 0;
                         break;
+                }
 
                 /*
                  * Is that owner really running on that cpu?
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 806d1b227a21..ab661ebc4895 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -3752,6 +3752,8 @@ static void task_fork_fair(struct task_struct *p)
 
         raw_spin_lock_irqsave(&rq->lock, flags);
 
+        update_rq_clock(rq);
+
         if (unlikely(task_cpu(p) != this_cpu))
                 __set_task_cpu(p, this_cpu);
 
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 056468eae7cf..a6b7e0e0f3eb 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -249,7 +249,7 @@ static int trace_lookup_stack(struct seq_file *m, long i)
 {
         unsigned long addr = stack_dump_trace[i];
 
-        return seq_printf(m, "%pF\n", (void *)addr);
+        return seq_printf(m, "%pS\n", (void *)addr);
 }
 
 static void print_disabled(struct seq_file *m)
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 613bc1f04610..0d53c8e853b1 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -206,6 +206,9 @@ void watchdog_overflow_callback(struct perf_event *event, int nmi,
                  struct perf_sample_data *data,
                  struct pt_regs *regs)
 {
+        /* Ensure the watchdog never gets throttled */
+        event->hw.interrupts = 0;
+
         if (__get_cpu_var(watchdog_nmi_touch) == true) {
                 __get_cpu_var(watchdog_nmi_touch) = false;
                 return;