diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 3 | ||||
| -rw-r--r-- | include/linux/sched.h | 3 | ||||
| -rw-r--r-- | kernel/softlockup.c | 45 | ||||
| -rw-r--r-- | kernel/sysctl.c | 20 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 4 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 26 |
6 files changed, 86 insertions, 15 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 30d44b78171..47e7d8794fc 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2034,6 +2034,9 @@ and is between 256 and 4096 characters. It is defined in the file snd-ymfpci= [HW,ALSA] + softlockup_panic= + [KNL] Should the soft-lockup detector generate panics. + sonypi.*= [HW] Sony Programmable I/O Control Device driver See Documentation/sonypi.txt diff --git a/include/linux/sched.h b/include/linux/sched.h index 1941d8b5cf1..af443a08431 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -295,10 +295,11 @@ extern void softlockup_tick(void); extern void spawn_softlockup_task(void); extern void touch_softlockup_watchdog(void); extern void touch_all_softlockup_watchdogs(void); -extern unsigned long softlockup_thresh; +extern unsigned int softlockup_panic; 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 a272d78185e..7bd8d1aadd5 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -13,6 +13,7 @@ #include <linux/delay.h> #include <linux/freezer.h> #include <linux/kthread.h> +#include <linux/lockdep.h> #include <linux/notifier.h> #include <linux/module.h> @@ -25,7 +26,22 @@ 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 + * soft-lockup occurs: + */ +unsigned int __read_mostly softlockup_panic = + CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE; + +static int __init softlockup_panic_setup(char *str) +{ + softlockup_panic = simple_strtoul(str, NULL, 0); + + return 1; +} +__setup("softlockup_panic=", softlockup_panic_setup); static int softlock_panic(struct notifier_block *this, unsigned long event, void *ptr) @@ -84,6 +100,14 @@ 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; @@ -92,11 +116,8 @@ void softlockup_tick(void) print_timestamp = per_cpu(print_timestamp, this_cpu); /* report at most once a second */ - if ((print_timestamp >= touch_timestamp && - print_timestamp < (touch_timestamp + 1)) || - did_panic || !per_cpu(watchdog_task, this_cpu)) { + if (print_timestamp == touch_timestamp || did_panic) return; - } /* do not print during early bootup: */ if (unlikely(system_state != SYSTEM_RUNNING)) { @@ -106,8 +127,11 @@ void softlockup_tick(void) now = get_timestamp(this_cpu); - /* Wake up the high-prio watchdog task every second: */ - if (now > (touch_timestamp + 1)) + /* + * Wake up the high-prio watchdog task twice per + * threshold timespan. + */ + if (now > touch_timestamp + softlockup_thresh/2) wake_up_process(per_cpu(watchdog_task, this_cpu)); /* Warn about unreasonable delays: */ @@ -121,11 +145,15 @@ void softlockup_tick(void) this_cpu, now - touch_timestamp, current->comm, task_pid_nr(current)); print_modules(); + print_irqtrace_events(current); if (regs) show_regs(regs); else dump_stack(); spin_unlock(&print_lock); + + if (softlockup_panic) + panic("softlockup: hung tasks"); } /* @@ -178,6 +206,9 @@ static void check_hung_task(struct task_struct *t, unsigned long now) t->last_switch_timestamp = now; touch_nmi_watchdog(); + + if (softlockup_panic) + panic("softlockup: blocked tasks"); } /* diff --git a/kernel/sysctl.c b/kernel/sysctl.c index b859e6b5a76..2a7b9d88706 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -88,12 +88,13 @@ extern int rcutorture_runnable; #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */ /* Constants used for minimum and maximum */ -#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM) +#if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP) static int one = 1; #endif #ifdef CONFIG_DETECT_SOFTLOCKUP static int sixty = 60; +static int neg_one = -1; #endif #ifdef CONFIG_MMU @@ -739,13 +740,24 @@ static struct ctl_table kern_table[] = { #ifdef CONFIG_DETECT_SOFTLOCKUP { .ctl_name = CTL_UNNUMBERED, + .procname = "softlockup_panic", + .data = &softlockup_panic, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &one, + }, + { + .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, }, { diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index beef7ccdf84..942fc7c8528 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -140,8 +140,6 @@ void tick_nohz_update_jiffies(void) if (!ts->tick_stopped) return; - touch_softlockup_watchdog(); - cpu_clear(cpu, nohz_cpu_mask); now = ktime_get(); ts->idle_waketime = now; @@ -149,6 +147,8 @@ void tick_nohz_update_jiffies(void) local_irq_save(flags); tick_do_update_jiffies64(now); local_irq_restore(flags); + + touch_softlockup_watchdog(); } void tick_nohz_stop_idle(int cpu) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ba106db5a65..882c5104899 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -150,7 +150,7 @@ config DETECT_SOFTLOCKUP help Say Y here to enable the kernel to detect "soft lockups", which are bugs that cause the kernel to loop in kernel - mode for more than 10 seconds, without giving other tasks a + mode for more than 60 seconds, without giving other tasks a chance to run. When a soft-lockup is detected, the kernel will print the @@ -162,6 +162,30 @@ config DETECT_SOFTLOCKUP can be detected via the NMI-watchdog, on platforms that support it.) +config BOOTPARAM_SOFTLOCKUP_PANIC + bool "Panic (Reboot) On Soft Lockups" + depends on DETECT_SOFTLOCKUP + help + Say Y here to enable the kernel to panic on "soft lockups", + which are bugs that cause the kernel to loop in kernel + mode for more than 60 seconds, without giving other tasks a + chance to run. + + The panic can be used in combination with panic_timeout, + to cause the system to reboot automatically after a + lockup has been detected. This feature is useful for + high-availability systems that have uptime guarantees and + where a lockup must be resolved ASAP. + + Say N if unsure. + +config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE + int + depends on DETECT_SOFTLOCKUP + range 0 1 + default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC + default 1 if BOOTPARAM_SOFTLOCKUP_PANIC + config SCHED_DEBUG bool "Collect scheduler debugging info" depends on DEBUG_KERNEL && PROC_FS |