ARM: dts: tx6: add enet_out clock for FEC

[karo-tx-linux.git] / kernel / watchdog.c

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 516203e665fcbddc8eb7f55fa7b5a2dd5634cfc5..c3319bd1b0408c1f5822748a4d0b1567c799760d 100644 (file)
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -31,6 +31,12 @@
 
 int watchdog_user_enabled = 1;
 int __read_mostly watchdog_thresh = 10;
+#ifdef CONFIG_SMP
+int __read_mostly sysctl_softlockup_all_cpu_backtrace;
+#else
+#define sysctl_softlockup_all_cpu_backtrace 0
+#endif
+
 static int __read_mostly watchdog_running;
 static u64 __read_mostly sample_period;
 
@@ -47,6 +53,7 @@ static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
 static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
 #endif
+static unsigned long soft_lockup_nmi_warn;
 
 /* boot commands */
 /*
@@ -95,6 +102,15 @@ static int __init nosoftlockup_setup(char *str)
 }
 __setup("nosoftlockup", nosoftlockup_setup);
 /*  */
+#ifdef CONFIG_SMP
+static int __init softlockup_all_cpu_backtrace_setup(char *str)
+{
+       sysctl_softlockup_all_cpu_backtrace =
+               !!simple_strtol(str, NULL, 0);
+       return 1;
+}
+__setup("softlockup_all_cpu_backtrace=", softlockup_all_cpu_backtrace_setup);
+#endif
 
 /*
  * Hard-lockup warnings should be triggered after just a few seconds. Soft-
@@ -271,6 +287,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
        unsigned long touch_ts = __this_cpu_read(watchdog_touch_ts);
        struct pt_regs *regs = get_irq_regs();
        int duration;
+       int softlockup_all_cpu_backtrace = sysctl_softlockup_all_cpu_backtrace;
 
        /* kick the hardlockup detector */
        watchdog_interrupt_count();
@@ -317,6 +334,17 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
                if (__this_cpu_read(soft_watchdog_warn) == true)
                        return HRTIMER_RESTART;
 
+               if (softlockup_all_cpu_backtrace) {
+                       /* Prevent multiple soft-lockup reports if one cpu is already
+                        * engaged in dumping cpu back traces
+                        */
+                       if (test_and_set_bit(0, &soft_lockup_nmi_warn)) {
+                               /* Someone else will report us. Let's give up */
+                               __this_cpu_write(soft_watchdog_warn, true);
+                               return HRTIMER_RESTART;
+                       }
+               }
+
                printk(KERN_EMERG "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
                        smp_processor_id(), duration,
                        current->comm, task_pid_nr(current));
@@ -327,6 +355,17 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
                else
                        dump_stack();
 
+               if (softlockup_all_cpu_backtrace) {
+                       /* Avoid generating two back traces for current
+                        * given that one is already made above
+                        */
+                       trigger_allbutself_cpu_backtrace();
+
+                       clear_bit(0, &soft_lockup_nmi_warn);
+                       /* Barrier to sync with other cpus */
+                       smp_mb__after_atomic();
+               }
+
                if (softlockup_panic)
                        panic("softlockup: hung tasks");
                __this_cpu_write(soft_watchdog_warn, true);
@@ -527,10 +566,8 @@ static void update_timers_all_cpus(void)
        int cpu;
 
        get_online_cpus();
-       preempt_disable();
        for_each_online_cpu(cpu)
                update_timers(cpu);
-       preempt_enable();
        put_online_cpus();
 }