watchdog: introduce the hardlockup_detector_disable() function

Have kvm_guest_init() use hardlockup_detector_disable() instead of
watchdog_enable_hardlockup_detector(false).

Remove the watchdog_hardlockup_detector_is_enabled() and the
watchdog_enable_hardlockup_detector() function which are no longer needed.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index e354cc6..9435620 100644 (file)
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -513,7 +513,7 @@ void __init kvm_guest_init(void)
         * can get false positives too easily, for example if the host is
         * overcommitted.
         */
-       watchdog_enable_hardlockup_detector(false);
+       hardlockup_detector_disable();
 }
 
 static noinline uint32_t __kvm_cpuid_base(void)

diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index 0426357..3d46fb4 100644 (file)
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -25,16 +25,11 @@ static inline void touch_nmi_watchdog(void)
 #endif
 
 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
-extern void watchdog_enable_hardlockup_detector(bool val);
-extern bool watchdog_hardlockup_detector_is_enabled(void);
+extern void hardlockup_detector_disable(void);
 #else
-static inline void watchdog_enable_hardlockup_detector(bool val)
+static inline void hardlockup_detector_disable(void)
 {
 }
-static inline bool watchdog_hardlockup_detector_is_enabled(void)
-{
-       return true;
-}
 #endif
 
 /*

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 49d0225..f2be11a 100644 (file)
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -83,8 +83,6 @@ static unsigned long soft_lockup_nmi_warn;
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 static int hardlockup_panic =
                        CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE;
-
-static bool hardlockup_detector_enabled = true;
 /*
  * We may not want to enable hard lockup detection by default in all cases,
  * for example when running the kernel as a guest on a hypervisor. In these
@@ -93,14 +91,9 @@ static bool hardlockup_detector_enabled = true;
  * kernel command line parameters are parsed, because otherwise it is not
  * possible to override this in hardlockup_panic_setup().
  */
-void watchdog_enable_hardlockup_detector(bool val)
-{
-       hardlockup_detector_enabled = val;
-}
-
-bool watchdog_hardlockup_detector_is_enabled(void)
+void hardlockup_detector_disable(void)
 {
-       return hardlockup_detector_enabled;
+       watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
 }
 
 static int __init hardlockup_panic_setup(char *str)
@@ -530,15 +523,6 @@ static int watchdog_nmi_enable(unsigned int cpu)
        if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
                goto out;
 
-       /*
-        * Some kernels need to default hard lockup detection to
-        * 'disabled', for example a guest on a hypervisor.
-        */
-       if (!watchdog_hardlockup_detector_is_enabled()) {
-               event = ERR_PTR(-ENOENT);
-               goto handle_err;
-       }
-
        /* is it already setup and enabled? */
        if (event && event->state > PERF_EVENT_STATE_OFF)
                goto out;
@@ -553,7 +537,6 @@ static int watchdog_nmi_enable(unsigned int cpu)
        /* Try to register using hardware perf events */
        event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
 
-handle_err:
        /* save cpu0 error for future comparision */
        if (cpu == 0 && IS_ERR(event))
                cpu0_err = PTR_ERR(event);