From 692297d8f96887f836d9049a653ed05a71cf48fb Mon Sep 17 00:00:00 2001
From: Ulrich Obergfell <uobergfe@redhat.com>
Date: Tue, 14 Apr 2015 15:44:19 -0700
Subject: [PATCH] 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>
---
arch/x86/kernel/kvm.c | 2 +-
include/linux/nmi.h | 9 ++-------
kernel/watchdog.c | 21 ++-------------------
3 files changed, 5 insertions(+), 27 deletions(-)
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index e354cc6446ab..9435620062df 100644
--- 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 0426357297d5..3d46fb4708e0 100644
--- 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 49d02250aaac..f2be11ab7e08 100644
--- 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)
+void hardlockup_detector_disable(void)
{
- hardlockup_detector_enabled = val;
-}
-
-bool watchdog_hardlockup_detector_is_enabled(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);