[RFC PATCH 1/4] watchdog: Remove hardlockup handler references

[Babu Moger]

Separate hardlockup code from watchdog.c. It is mostly straight forward.
Remove everything inside CONFIG_HARDLOCKUP_DETECTORS. This code will go
to file watchdog_hld.c. 

We also define weak handlers watchdog_nmi_enable and watchdog_nmi_disable.

Signed-off-by: Babu Moger 
---
 kernel/watchdog.c |  251 ++---
 1 files changed, 7 insertions(+), 244 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 9acb29f..a88e179 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -24,7 +24,6 @@
 
 #include 
 #include 
-#include 
 #include 
 
 /*
@@ -100,50 +99,8 @@
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
 static DEFINE_PER_CPU(unsigned long, soft_lockup_hrtimer_cnt);
 static DEFINE_PER_CPU(struct task_struct *, softlockup_task_ptr_saved);
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-static DEFINE_PER_CPU(bool, hard_watchdog_warn);
-static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
-static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
-static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
-#endif
 static unsigned long soft_lockup_nmi_warn;
 
-/* boot commands */
-/*
- * Should we panic when a soft-lockup or hard-lockup occurs:
- */
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-unsigned int __read_mostly hardlockup_panic =
-   CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE;
-static unsigned long hardlockup_allcpu_dumped;
-/*
- * 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
- * cases this function can be called to disable hard lockup detection. This
- * function should only be executed once by the boot processor before the
- * kernel command line parameters are parsed, because otherwise it is not
- * possible to override this in hardlockup_panic_setup().
- */
-void hardlockup_detector_disable(void)
-{
-   watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
-}
-
-static int __init hardlockup_panic_setup(char *str)
-{
-   if (!strncmp(str, "panic", 5))
-   hardlockup_panic = 1;
-   else if (!strncmp(str, "nopanic", 7))
-   hardlockup_panic = 0;
-   else if (!strncmp(str, "0", 1))
-   watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
-   else if (!strncmp(str, "1", 1))
-   watchdog_enabled |= NMI_WATCHDOG_ENABLED;
-   return 1;
-}
-__setup("nmi_watchdog=", hardlockup_panic_setup);
-#endif
-
 unsigned int __read_mostly softlockup_panic =
CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
 
@@ -264,43 +221,12 @@ void touch_all_softlockup_watchdogs(void)
wq_watchdog_touch(-1);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-void touch_nmi_watchdog(void)
-{
-   /*
-* Using __raw here because some code paths have
-* preemption enabled.  If preemption is enabled
-* then interrupts should be enabled too, in which
-* case we shouldn't have to worry about the watchdog
-* going off.
-*/
-   raw_cpu_write(watchdog_nmi_touch, true);
-   touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL(touch_nmi_watchdog);
-
-#endif
-
 void touch_softlockup_watchdog_sync(void)
 {
__this_cpu_write(softlockup_touch_sync, true);
__this_cpu_write(watchdog_touch_ts, 0);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-/* watchdog detector functions */
-static bool is_hardlockup(void)
-{
-   unsigned long hrint = __this_cpu_read(hrtimer_interrupts);
-
-   if (__this_cpu_read(hrtimer_interrupts_saved) == hrint)
-   return true;
-
-   __this_cpu_write(hrtimer_interrupts_saved, hrint);
-   return false;
-}
-#endif
-
 static int is_softlockup(unsigned long touch_ts)
 {
unsigned long now = get_timestamp();
@@ -313,78 +239,18 @@ static int is_softlockup(unsigned long touch_ts)
return 0;
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-
-static struct perf_event_attr wd_hw_attr = {
-   .type   = PERF_TYPE_HARDWARE,
-   .config = PERF_COUNT_HW_CPU_CYCLES,
-   .size   = sizeof(struct perf_event_attr),
-   .pinned = 1,
-   .disabled   = 1,
-};
-
-/* Callback function for perf event subsystem */
-static void watchdog_overflow_callback(struct perf_event *event,
-struct perf_sample_data *data,
-struct pt_regs *regs)
-{
-   /* Ensure the watchdog never gets throttled */
-   event->hw.interrupts = 0;
-
-   if (__this_cpu_read(watchdog_nmi_touch) == true) {
-   __this_cpu_write(watchdog_nmi_touch, false);
-   return;
-   }
-
-   /* check for a hardlockup
-* This is done by making sure our timer interrupt
-* is incrementing.  The timer interrupt should have
-* fired multiple times before we overflow'd.  If it hasn't
-* then this is a good indication the cpu is stuck
-*/
-   if (is_hardlockup()) {
-   

[RFC PATCH 1/4] watchdog: Remove hardlockup handler references

[Babu Moger]

Separate hardlockup code from watchdog.c. It is mostly straight forward.
Remove everything inside CONFIG_HARDLOCKUP_DETECTORS. This code will go
to file watchdog_hld.c. 

We also define weak handlers watchdog_nmi_enable and watchdog_nmi_disable.

Signed-off-by: Babu Moger 
---
 kernel/watchdog.c |  251 ++---
 1 files changed, 7 insertions(+), 244 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 9acb29f..a88e179 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -24,7 +24,6 @@
 
 #include 
 #include 
-#include 
 #include 
 
 /*
@@ -100,50 +99,8 @@
 static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts);
 static DEFINE_PER_CPU(unsigned long, soft_lockup_hrtimer_cnt);
 static DEFINE_PER_CPU(struct task_struct *, softlockup_task_ptr_saved);
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-static DEFINE_PER_CPU(bool, hard_watchdog_warn);
-static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
-static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
-static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
-#endif
 static unsigned long soft_lockup_nmi_warn;
 
-/* boot commands */
-/*
- * Should we panic when a soft-lockup or hard-lockup occurs:
- */
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-unsigned int __read_mostly hardlockup_panic =
-   CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE;
-static unsigned long hardlockup_allcpu_dumped;
-/*
- * 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
- * cases this function can be called to disable hard lockup detection. This
- * function should only be executed once by the boot processor before the
- * kernel command line parameters are parsed, because otherwise it is not
- * possible to override this in hardlockup_panic_setup().
- */
-void hardlockup_detector_disable(void)
-{
-   watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
-}
-
-static int __init hardlockup_panic_setup(char *str)
-{
-   if (!strncmp(str, "panic", 5))
-   hardlockup_panic = 1;
-   else if (!strncmp(str, "nopanic", 7))
-   hardlockup_panic = 0;
-   else if (!strncmp(str, "0", 1))
-   watchdog_enabled &= ~NMI_WATCHDOG_ENABLED;
-   else if (!strncmp(str, "1", 1))
-   watchdog_enabled |= NMI_WATCHDOG_ENABLED;
-   return 1;
-}
-__setup("nmi_watchdog=", hardlockup_panic_setup);
-#endif
-
 unsigned int __read_mostly softlockup_panic =
CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
 
@@ -264,43 +221,12 @@ void touch_all_softlockup_watchdogs(void)
wq_watchdog_touch(-1);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-void touch_nmi_watchdog(void)
-{
-   /*
-* Using __raw here because some code paths have
-* preemption enabled.  If preemption is enabled
-* then interrupts should be enabled too, in which
-* case we shouldn't have to worry about the watchdog
-* going off.
-*/
-   raw_cpu_write(watchdog_nmi_touch, true);
-   touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL(touch_nmi_watchdog);
-
-#endif
-
 void touch_softlockup_watchdog_sync(void)
 {
__this_cpu_write(softlockup_touch_sync, true);
__this_cpu_write(watchdog_touch_ts, 0);
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-/* watchdog detector functions */
-static bool is_hardlockup(void)
-{
-   unsigned long hrint = __this_cpu_read(hrtimer_interrupts);
-
-   if (__this_cpu_read(hrtimer_interrupts_saved) == hrint)
-   return true;
-
-   __this_cpu_write(hrtimer_interrupts_saved, hrint);
-   return false;
-}
-#endif
-
 static int is_softlockup(unsigned long touch_ts)
 {
unsigned long now = get_timestamp();
@@ -313,78 +239,18 @@ static int is_softlockup(unsigned long touch_ts)
return 0;
 }
 
-#ifdef CONFIG_HARDLOCKUP_DETECTOR
-
-static struct perf_event_attr wd_hw_attr = {
-   .type   = PERF_TYPE_HARDWARE,
-   .config = PERF_COUNT_HW_CPU_CYCLES,
-   .size   = sizeof(struct perf_event_attr),
-   .pinned = 1,
-   .disabled   = 1,
-};
-
-/* Callback function for perf event subsystem */
-static void watchdog_overflow_callback(struct perf_event *event,
-struct perf_sample_data *data,
-struct pt_regs *regs)
-{
-   /* Ensure the watchdog never gets throttled */
-   event->hw.interrupts = 0;
-
-   if (__this_cpu_read(watchdog_nmi_touch) == true) {
-   __this_cpu_write(watchdog_nmi_touch, false);
-   return;
-   }
-
-   /* check for a hardlockup
-* This is done by making sure our timer interrupt
-* is incrementing.  The timer interrupt should have
-* fired multiple times before we overflow'd.  If it hasn't
-* then this is a good indication the cpu is stuck
-*/
-   if (is_hardlockup()) {
-   int this_cpu =