Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / kernel / watchdog.c

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index d9961ea1c3f4934da9d8e051c99df5a99d4b0b52..18bb15776c57162b60675adf69e7afd765b34fb0 100644 (file)
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -363,8 +363,14 @@ static int watchdog_nmi_enable(int cpu)
                goto out_save;
        }
 
-       printk(KERN_ERR "NMI watchdog disabled for cpu%i: unable to create perf event: %ld\n",
-              cpu, PTR_ERR(event));
+
+       /* vary the KERN level based on the returned errno */
+       if (PTR_ERR(event) == -EOPNOTSUPP)
+               printk(KERN_INFO "NMI watchdog disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
+       else if (PTR_ERR(event) == -ENOENT)
+               printk(KERN_WARNING "NMI watchdog disabled (cpu%i): hardware events not enabled\n", cpu);
+       else
+               printk(KERN_ERR "NMI watchdog disabled (cpu%i): unable to create perf event: %ld\n", cpu, PTR_ERR(event));
        return PTR_ERR(event);
 
        /* success path */
@@ -429,9 +435,6 @@ static int watchdog_enable(int cpu)
                wake_up_process(p);
        }
 
-       /* if any cpu succeeds, watchdog is considered enabled for the system */
-       watchdog_enabled = 1;
-
        return 0;
 }
 
@@ -459,12 +462,16 @@ static void watchdog_disable(int cpu)
 static void watchdog_enable_all_cpus(void)
 {
        int cpu;
-       int result = 0;
+
+       watchdog_enabled = 0;
 
        for_each_online_cpu(cpu)
-               result += watchdog_enable(cpu);
+               if (!watchdog_enable(cpu))
+                       /* if any cpu succeeds, watchdog is considered
+                          enabled for the system */
+                       watchdog_enabled = 1;
 
-       if (result)
+       if (!watchdog_enabled)
                printk(KERN_ERR "watchdog: failed to be enabled on some cpus\n");
 
 }
@@ -492,10 +499,12 @@ int proc_dowatchdog_enabled(struct ctl_table *table, int write,
 {
        proc_dointvec(table, write, buffer, length, ppos);
 
-       if (watchdog_enabled)
-               watchdog_enable_all_cpus();
-       else
-               watchdog_disable_all_cpus();
+       if (write) {
+               if (watchdog_enabled)
+                       watchdog_enable_all_cpus();
+               else
+                       watchdog_disable_all_cpus();
+       }
        return 0;
 }