diff options
author | Ingo Molnar <mingo@elte.hu> | 2008-10-28 16:26:12 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2008-10-28 16:26:12 +0100 |
commit | 7a9787e1eba95a166265e6a260cf30af04ef0a99 (patch) | |
tree | e730a4565e0318140d2fbd2f0415d18a339d7336 /kernel/softlockup.c | |
parent | 41b9eb264c8407655db57b60b4457fe1b2ec9977 (diff) | |
parent | 0173a3265b228da319ceb9c1ec6a5682fd1b2d92 (diff) |
Merge commit 'v2.6.28-rc2' into x86/pci-ioapic-boot-irq-quirks
Diffstat (limited to 'kernel/softlockup.c')
-rw-r--r-- | kernel/softlockup.c | 75 |
1 files changed, 63 insertions, 12 deletions
diff --git a/kernel/softlockup.c b/kernel/softlockup.c index a272d78185e..3953e4aed73 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"); } /* @@ -195,14 +226,15 @@ static void check_hung_uninterruptible_tasks(int this_cpu) * If the system crashed already then all bets are off, * do not report extra hung tasks: */ - if ((tainted & TAINT_DIE) || did_panic) + if (test_taint(TAINT_DIE) || did_panic) return; read_lock(&tasklist_lock); do_each_thread(g, t) { if (!--max_count) goto unlock; - if (t->state & TASK_UNINTERRUPTIBLE) + /* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */ + if (t->state == TASK_UNINTERRUPTIBLE) check_hung_task(t, now); } while_each_thread(g, t); unlock: @@ -307,14 +339,33 @@ static struct notifier_block __cpuinitdata cpu_nfb = { .notifier_call = cpu_callback }; -__init void spawn_softlockup_task(void) +static int __initdata nosoftlockup; + +static int __init nosoftlockup_setup(char *str) +{ + nosoftlockup = 1; + return 1; +} +__setup("nosoftlockup", nosoftlockup_setup); + +static int __init spawn_softlockup_task(void) { void *cpu = (void *)(long)smp_processor_id(); - int err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); + int err; + + if (nosoftlockup) + return 0; - BUG_ON(err == NOTIFY_BAD); + err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); + if (err == NOTIFY_BAD) { + BUG(); + return 1; + } cpu_callback(&cpu_nfb, CPU_ONLINE, cpu); register_cpu_notifier(&cpu_nfb); atomic_notifier_chain_register(&panic_notifier_list, &panic_block); + + return 0; } +early_initcall(spawn_softlockup_task); |