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authorDimitri Sivanich <sivanich@sgi.com>2008-05-12 21:21:14 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-05-25 06:35:03 +0200
commit9383d9679056e6cc4e7ff70f31da945a268238f4 (patch)
treec6678a8c4e0fed0739e43f24b608d51856af6f1f
parent9c44bc03fff44ff04237a7d92e35304a0e50c331 (diff)
softlockup: fix softlockup_thresh unaligned access and disable detection at runtime
Fix unaligned access errors when setting softlockup_thresh on 64 bit platforms. Allow softlockup detection to be disabled by setting softlockup_thresh <= 0. Detect that boot time softlockup detection has been disabled earlier in softlockup_tick. Signed-off-by: Dimitri Sivanich <sivanich@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--include/linux/sched.h2
-rw-r--r--kernel/softlockup.c12
-rw-r--r--kernel/sysctl.c9
3 files changed, 16 insertions, 7 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 71f5972dc48e..ea26221644e2 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -295,10 +295,10 @@ extern void spawn_softlockup_task(void);
extern void touch_softlockup_watchdog(void);
extern void touch_all_softlockup_watchdogs(void);
extern unsigned int softlockup_panic;
-extern unsigned long softlockup_thresh;
extern unsigned long sysctl_hung_task_check_count;
extern unsigned long sysctl_hung_task_timeout_secs;
extern unsigned long sysctl_hung_task_warnings;
+extern int softlockup_thresh;
#else
static inline void softlockup_tick(void)
{
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 78e0ad21cb0c..a3a0b239b7f7 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -25,7 +25,7 @@ static DEFINE_PER_CPU(unsigned long, print_timestamp);
static DEFINE_PER_CPU(struct task_struct *, watchdog_task);
static int __read_mostly did_panic;
-unsigned long __read_mostly softlockup_thresh = 60;
+int __read_mostly softlockup_thresh = 60;
/*
* Should we panic (and reboot, if panic_timeout= is set) when a
@@ -94,6 +94,14 @@ void softlockup_tick(void)
struct pt_regs *regs = get_irq_regs();
unsigned long now;
+ /* Is detection switched off? */
+ if (!per_cpu(watchdog_task, this_cpu) || softlockup_thresh <= 0) {
+ /* Be sure we don't false trigger if switched back on */
+ if (touch_timestamp)
+ per_cpu(touch_timestamp, this_cpu) = 0;
+ return;
+ }
+
if (touch_timestamp == 0) {
touch_softlockup_watchdog();
return;
@@ -104,7 +112,7 @@ void softlockup_tick(void)
/* report at most once a second */
if ((print_timestamp >= touch_timestamp &&
print_timestamp < (touch_timestamp + 1)) ||
- did_panic || !per_cpu(watchdog_task, this_cpu)) {
+ did_panic) {
return;
}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 2d3b388c402d..31c19a79738d 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -84,12 +84,13 @@ extern int latencytop_enabled;
extern int sysctl_nr_open_min, sysctl_nr_open_max;
/* Constants used for minimum and maximum */
-#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM)
+#ifdef CONFIG_HIGHMEM
static int one = 1;
#endif
#ifdef CONFIG_DETECT_SOFTLOCKUP
static int sixty = 60;
+static int neg_one = -1;
#endif
#ifdef CONFIG_MMU
@@ -742,11 +743,11 @@ static struct ctl_table kern_table[] = {
.ctl_name = CTL_UNNUMBERED,
.procname = "softlockup_thresh",
.data = &softlockup_thresh,
- .maxlen = sizeof(unsigned long),
+ .maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_doulongvec_minmax,
+ .proc_handler = &proc_dointvec_minmax,
.strategy = &sysctl_intvec,
- .extra1 = &one,
+ .extra1 = &neg_one,
.extra2 = &sixty,
},
{