[PATCH 7/6] [watchdog] resolve softlockup.c conflicts

Don Zickus
2010-04-20T16:17:32Z

My changes with the softlockup code uses an older version of softlockup.c.
A couple of commits have been committed that were not on the branch I am
using. This patch resolves those conflicts.

Commit 8c2eb4 softlockup: Stop spurious softlockup messages due to overflow
d6ad3e softlockup: Add sched_clock_tick() to avoid kernel warning on kgdb resume

Conflicts:

include/linux/sched.h
kernel/kgdb.c
kernel/softlockup.c

Signed-off-by: Don Zickus <dzickus@redhat.com>

--

Hi Ingo,

If there is a better way to deal with these conflicts please let me know.

---
include/linux/sched.h | 4 ++++
kernel/kgdb.c | 6 +++---
kernel/watchdog.c | 17 ++++++++++++++++-
3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 0c128ad..e039e22 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -310,6 +310,7 @@ extern void sched_show_task(struct task_struct *p);
#ifdef CONFIG_LOCKUP_DETECTOR
extern void touch_watchdog(void);
extern void touch_all_watchdogs(void);
+extern void touch_watchdog_sync(void);
extern unsigned int softlockup_panic;
extern int softlockup_thresh;
extern int proc_dowatchdog_thresh(struct ctl_table *table, int write,
@@ -322,6 +323,9 @@ static inline void touch_watchdog(void)
static inline void touch_all_watchdogs(void)
{
}
+static inline void touch_watchdog_sync(void)
+{
+}
#endif

#ifdef CONFIG_DETECT_HUNG_TASK
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index 15df969..da98119 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -596,7 +596,7 @@ static void kgdb_wait(struct pt_regs *regs)

/* Signal the primary CPU that we are done: */
atomic_set(&cpu_in_kgdb[cpu], 0);
- touch_watchdog();
+ touch_watchdog_sync();
clocksource_touch_watchdog();
local_irq_restore(flags);
}
@@ -1450,7 +1450,7 @@ acquirelock:
(kgdb_info[cpu].task &&
kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) {
atomic_set(&kgdb_active, -1);
- touch_watchdog();
+ touch_watchdog_sync();
clocksource_touch_watchdog();
local_irq_restore(flags);

@@ -1550,7 +1550,7 @@ kgdb_restore:
}
/* Free kgdb_active */
atomic_set(&kgdb_active, -1);
- touch_watchdog();
+ touch_watchdog_sync();
clocksource_touch_watchdog();
local_irq_restore(flags);

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 73529a8..9898c7c 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -33,6 +33,7 @@ int __read_mostly softlockup_thresh = 60;
static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog);
static DEFINE_PER_CPU(struct hrtimer, watchdog_hrtimer);
+static DEFINE_PER_CPU(bool, watchdog_touch_sync);
#define HARDLOCKUP 1
#define SOFTLOCKUP 2
static DEFINE_PER_CPU(char, watchdog_warn);
@@ -138,6 +139,12 @@ void touch_all_watchdogs(void)
per_cpu(watchdog_touch_ts, cpu) = 0;
}

+void touch_watchdog_sync(void)
+{
+ __raw_get_cpu_var(watchdog_touch_sync) = true;
+ __raw_get_cpu_var(watchdog_touch_ts) = 0;
+}
+
void touch_nmi_watchdog(void)
{
touch_watchdog();
@@ -163,7 +170,7 @@ static int is_softlockup(unsigned long touch_ts, int cpu)
unsigned long now = get_timestamp(cpu);

/* Warn about unreasonable delays: */
- if (now > (touch_ts + softlockup_thresh))
+ if (time_after(now, touch_ts + softlockup_thresh))
return now - touch_ts;

return 0;
@@ -254,6 +261,14 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
hrtimer_forward_now(hrtimer, ns_to_ktime(get_sample_period()));

if (touch_ts == 0) {
+ if (unlikely(per_cpu(watchdog_touch_sync, this_cpu))) {
+ /*
+ * If the time stamp was touched atomically
+ * make sure the scheduler tick is up to date.
+ */
+ per_cpu(watchdog_touch_sync, this_cpu) = false;
+ sched_clock_tick();
+ }
__touch_watchdog();
return HRTIMER_RESTART;
}
--
1.6.5.2