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

Pull perf fixes from Ingo Molnar.

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  watchdog: Quiet down the boot messages
  perf/x86: Fix broken LBR fixup code
  tracing: Have tracing_off() actually turn tracing off

1 files changed, 18 insertions, 1 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index e5e1d85b8c7c..4b1dfba70f7c 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -372,6 +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;
@@ -390,11 +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)