diff options
| -rw-r--r-- | arch/i386/kernel/nmi.c | 5 | ||||
| -rw-r--r-- | arch/i386/kernel/time.c | 1 | ||||
| -rw-r--r-- | arch/x86_64/kernel/nmi.c | 2 | ||||
| -rw-r--r-- | arch/x86_64/kernel/time.c | 1 | ||||
| -rw-r--r-- | drivers/mtd/nand/nand_base.c | 1 | ||||
| -rw-r--r-- | include/linux/sched.h | 17 | ||||
| -rw-r--r-- | init/main.c | 1 | ||||
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/power/swsusp.c | 1 | ||||
| -rw-r--r-- | kernel/softlockup.c | 151 | ||||
| -rw-r--r-- | kernel/timer.c | 1 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 19 |
12 files changed, 201 insertions, 0 deletions
diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c index 8bbdbda..0178457 100644 --- a/arch/i386/kernel/nmi.c +++ b/arch/i386/kernel/nmi.c @@ -478,6 +478,11 @@ void touch_nmi_watchdog (void) */ for (i = 0; i < NR_CPUS; i++) alert_counter[i] = 0; + + /* + * Tickle the softlockup detector too: + */ + touch_softlockup_watchdog(); } extern void die_nmi(struct pt_regs *, const char *msg); diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c index 6f794a7..b0c5ee2 100644 --- a/arch/i386/kernel/time.c +++ b/arch/i386/kernel/time.c @@ -422,6 +422,7 @@ static int timer_resume(struct sys_device *dev) last_timer->resume(); cur_timer = last_timer; last_timer = NULL; + touch_softlockup_watchdog(); return 0; } diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c index 64a8e05..84cae81 100644 --- a/arch/x86_64/kernel/nmi.c +++ b/arch/x86_64/kernel/nmi.c @@ -463,6 +463,8 @@ void touch_nmi_watchdog (void) */ for (i = 0; i < NR_CPUS; i++) per_cpu(nmi_touch, i) = 1; + + touch_softlockup_watchdog(); } void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason) diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 66bf6dd..2b5d9da 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -1041,6 +1041,7 @@ static int timer_resume(struct sys_device *dev) write_sequnlock_irqrestore(&xtime_lock,flags); jiffies += sleep_length; wall_jiffies += sleep_length; + touch_softlockup_watchdog(); return 0; } diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index eee5115..04e5431 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -526,6 +526,7 @@ static void nand_wait_ready(struct mtd_info *mtd) do { if (this->dev_ready(mtd)) return; + touch_softlockup_watchdog(); } while (time_before(jiffies, timeo)); } diff --git a/include/linux/sched.h b/include/linux/sched.h index dec5827..5fb31be 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -176,6 +176,23 @@ extern void trap_init(void); extern void update_process_times(int user); extern void scheduler_tick(void); +#ifdef CONFIG_DETECT_SOFTLOCKUP +extern void softlockup_tick(struct pt_regs *regs); +extern void spawn_softlockup_task(void); +extern void touch_softlockup_watchdog(void); +#else +static inline void softlockup_tick(struct pt_regs *regs) +{ +} +static inline void spawn_softlockup_task(void) +{ +} +static inline void touch_softlockup_watchdog(void) +{ +} +#endif + + /* Attach to any functions which should be ignored in wchan output. */ #define __sched __attribute__((__section__(".sched.text"))) /* Is this address in the __sched functions? */ diff --git a/init/main.c b/init/main.c index ff41006..a29fb2a 100644 --- a/init/main.c +++ b/init/main.c @@ -614,6 +614,7 @@ static void do_pre_smp_initcalls(void) migration_init(); #endif spawn_ksoftirqd(); + spawn_softlockup_task(); } static void run_init_process(char *init_filename) diff --git a/kernel/Makefile b/kernel/Makefile index cb05cd0..8d57a2f 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_AUDIT) += audit.o obj-$(CONFIG_AUDITSYSCALL) += auditsc.o obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_SYSFS) += ksysfs.o +obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_SECCOMP) += seccomp.o diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c index eaacd5c..d967e87 100644 --- a/kernel/power/swsusp.c +++ b/kernel/power/swsusp.c @@ -1059,6 +1059,7 @@ int swsusp_resume(void) BUG_ON(!error); restore_processor_state(); restore_highmem(); + touch_softlockup_watchdog(); device_power_up(); local_irq_enable(); return error; diff --git a/kernel/softlockup.c b/kernel/softlockup.c new file mode 100644 index 0000000..7597620 --- /dev/null +++ b/kernel/softlockup.c @@ -0,0 +1,151 @@ +/* + * Detect Soft Lockups + * + * started by Ingo Molnar, (C) 2005, Red Hat + * + * this code detects soft lockups: incidents in where on a CPU + * the kernel does not reschedule for 10 seconds or more. + */ + +#include <linux/mm.h> +#include <linux/cpu.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/kthread.h> +#include <linux/notifier.h> +#include <linux/module.h> + +static DEFINE_SPINLOCK(print_lock); + +static DEFINE_PER_CPU(unsigned long, timestamp) = 0; +static DEFINE_PER_CPU(unsigned long, print_timestamp) = 0; +static DEFINE_PER_CPU(struct task_struct *, watchdog_task); + +static int did_panic = 0; +static int softlock_panic(struct notifier_block *this, unsigned long event, + void *ptr) +{ + did_panic = 1; + + return NOTIFY_DONE; +} + +static struct notifier_block panic_block = { + .notifier_call = softlock_panic, +}; + +void touch_softlockup_watchdog(void) +{ + per_cpu(timestamp, raw_smp_processor_id()) = jiffies; +} +EXPORT_SYMBOL(touch_softlockup_watchdog); + +/* + * This callback runs from the timer interrupt, and checks + * whether the watchdog thread has hung or not: + */ +void softlockup_tick(struct pt_regs *regs) +{ + int this_cpu = smp_processor_id(); + unsigned long timestamp = per_cpu(timestamp, this_cpu); + + if (per_cpu(print_timestamp, this_cpu) == timestamp) + return; + + /* Do not cause a second panic when there already was one */ + if (did_panic) + return; + + if (time_after(jiffies, timestamp + 10*HZ)) { + per_cpu(print_timestamp, this_cpu) = timestamp; + + spin_lock(&print_lock); + printk(KERN_ERR "BUG: soft lockup detected on CPU#%d!\n", + this_cpu); + show_regs(regs); + spin_unlock(&print_lock); + } +} + +/* + * The watchdog thread - runs every second and touches the timestamp. + */ +static int watchdog(void * __bind_cpu) +{ + struct sched_param param = { .sched_priority = 99 }; + int this_cpu = (long) __bind_cpu; + + printk("softlockup thread %d started up.\n", this_cpu); + + sched_setscheduler(current, SCHED_FIFO, ¶m); + current->flags |= PF_NOFREEZE; + + set_current_state(TASK_INTERRUPTIBLE); + + /* + * Run briefly once per second - if this gets delayed for + * more than 10 seconds then the debug-printout triggers + * in softlockup_tick(): + */ + while (!kthread_should_stop()) { + msleep_interruptible(1000); + touch_softlockup_watchdog(); + } + __set_current_state(TASK_RUNNING); + + return 0; +} + +/* + * Create/destroy watchdog threads as CPUs come and go: + */ +static int __devinit +cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) +{ + int hotcpu = (unsigned long)hcpu; + struct task_struct *p; + + switch (action) { + case CPU_UP_PREPARE: + BUG_ON(per_cpu(watchdog_task, hotcpu)); + p = kthread_create(watchdog, hcpu, "watchdog/%d", hotcpu); + if (IS_ERR(p)) { + printk("watchdog for %i failed\n", hotcpu); + return NOTIFY_BAD; + } + per_cpu(watchdog_task, hotcpu) = p; + kthread_bind(p, hotcpu); + break; + case CPU_ONLINE: + + wake_up_process(per_cpu(watchdog_task, hotcpu)); + break; +#ifdef CONFIG_HOTPLUG_CPU + case CPU_UP_CANCELED: + /* Unbind so it can run. Fall thru. */ + kthread_bind(per_cpu(watchdog_task, hotcpu), smp_processor_id()); + case CPU_DEAD: + p = per_cpu(watchdog_task, hotcpu); + per_cpu(watchdog_task, hotcpu) = NULL; + kthread_stop(p); + break; +#endif /* CONFIG_HOTPLUG_CPU */ + } + return NOTIFY_OK; +} + +static struct notifier_block __devinitdata cpu_nfb = { + .notifier_call = cpu_callback +}; + +__init void spawn_softlockup_task(void) +{ + void *cpu = (void *)(long)smp_processor_id(); + + cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); + cpu_callback(&cpu_nfb, CPU_ONLINE, cpu); + register_cpu_notifier(&cpu_nfb); + + notifier_chain_register(&panic_notifier_list, &panic_block); +} + diff --git a/kernel/timer.c b/kernel/timer.c index 5377f40..1433d87 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -950,6 +950,7 @@ void do_timer(struct pt_regs *regs) { jiffies_64++; update_times(); + softlockup_tick(regs); } #ifdef __ARCH_WANT_SYS_ALARM diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 299f7f3..3754c9a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -46,6 +46,25 @@ config LOG_BUF_SHIFT 13 => 8 KB 12 => 4 KB +config DETECT_SOFTLOCKUP + bool "Detect Soft Lockups" + depends on DEBUG_KERNEL + default y + 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 + chance to run. + + When a soft-lockup is detected, the kernel will print the + current stack trace (which you should report), but the + system will stay locked up. This feature has negligible + overhead. + + (Note that "hard lockups" are separate type of bugs that + can be detected via the NMI-watchdog, on platforms that + support it.) + config SCHEDSTATS bool "Collect scheduler statistics" depends on DEBUG_KERNEL && PROC_FS |
