printk: Optimize if statement logic where newline exists

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

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index df30ee08bdd42161105a9564871cc80491d0b7aa..4b1dfba70f7cf8ae7397623656a9b695028f702a 100644 (file)
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -24,6 +24,7 @@
 #include <linux/sysctl.h>
 
 #include <asm/irq_regs.h>
+#include <linux/kvm_para.h>
 #include <linux/perf_event.h>
 
 int watchdog_enabled = 1;
@@ -280,6 +281,9 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
                        __this_cpu_write(softlockup_touch_sync, false);
                        sched_clock_tick();
                }
+
+               /* Clear the guest paused flag on watchdog reset */
+               kvm_check_and_clear_guest_paused();
                __touch_watchdog();
                return HRTIMER_RESTART;
        }
@@ -292,6 +296,14 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
         */
        duration = is_softlockup(touch_ts);
        if (unlikely(duration)) {
+               /*
+                * If a virtual machine is stopped by the host it can look to
+                * the watchdog like a soft lockup, check to see if the host
+                * stopped the vm before we issue the warning
+                */
+               if (kvm_check_and_clear_guest_paused())
+                       return HRTIMER_RESTART;
+
                /* only warn once */
                if (__this_cpu_read(soft_watchdog_warn) == true)
                        return HRTIMER_RESTART;
@@ -360,6 +372,13 @@ static int watchdog(void *unused)
 
 
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
+/*
+ * People like the simple clean cpu node info on boot.
+ * Reduce the watchdog noise by only printing messages
+ * that are different from what cpu0 displayed.
+ */
+static unsigned long cpu0_err;
+
 static int watchdog_nmi_enable(int cpu)
 {
        struct perf_event_attr *wd_attr;
@@ -378,11 +397,21 @@ static int watchdog_nmi_enable(int cpu)
 
        /* Try to register using hardware perf events */
        event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
+
+       /* save cpu0 error for future comparision */
+       if (cpu == 0 && IS_ERR(event))
+               cpu0_err = PTR_ERR(event);
+
        if (!IS_ERR(event)) {
-               pr_info("enabled, takes one hw-pmu counter.\n");
+               /* only print for cpu0 or different than cpu0 */
+               if (cpu == 0 || cpu0_err)
+                       pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
                goto out_save;
        }
 
+       /* skip displaying the same error again */
+       if (cpu > 0 && (PTR_ERR(event) == cpu0_err))
+               return PTR_ERR(event);
 
        /* vary the KERN level based on the returned errno */
        if (PTR_ERR(event) == -EOPNOTSUPP)