diff options
| -rw-r--r-- | Documentation/x86_64/machinecheck | 7 | ||||
| -rw-r--r-- | arch/x86_64/kernel/mce.c | 32 |
2 files changed, 30 insertions, 9 deletions
diff --git a/Documentation/x86_64/machinecheck b/Documentation/x86_64/machinecheck index 068a6d9..feaeaf6 100644 --- a/Documentation/x86_64/machinecheck +++ b/Documentation/x86_64/machinecheck @@ -36,7 +36,12 @@ between all CPUs. check_interval How often to poll for corrected machine check errors, in seconds - (Note output is hexademical). Default 5 minutes. + (Note output is hexademical). Default 5 minutes. When the poller + finds MCEs it triggers an exponential speedup (poll more often) on + the polling interval. When the poller stops finding MCEs, it + triggers an exponential backoff (poll less often) on the polling + interval. The check_interval variable is both the initial and + maximum polling interval. tolerant Tolerance level. When a machine check exception occurs for a non diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c index 8011a8e..fa26726 100644 --- a/arch/x86_64/kernel/mce.c +++ b/arch/x86_64/kernel/mce.c @@ -323,10 +323,13 @@ void mce_log_therm_throt_event(unsigned int cpu, __u64 status) #endif /* CONFIG_X86_MCE_INTEL */ /* - * Periodic polling timer for "silent" machine check errors. + * Periodic polling timer for "silent" machine check errors. If the + * poller finds an MCE, poll 2x faster. When the poller finds no more + * errors, poll 2x slower (up to check_interval seconds). */ static int check_interval = 5 * 60; /* 5 minutes */ +static int next_interval; /* in jiffies */ static void mcheck_timer(struct work_struct *work); static DECLARE_DELAYED_WORK(mcheck_work, mcheck_timer); @@ -339,7 +342,6 @@ static void mcheck_check_cpu(void *info) static void mcheck_timer(struct work_struct *work) { on_each_cpu(mcheck_check_cpu, NULL, 1, 1); - schedule_delayed_work(&mcheck_work, check_interval * HZ); /* * It's ok to read stale data here for notify_user and @@ -349,17 +351,30 @@ static void mcheck_timer(struct work_struct *work) * writes. */ if (notify_user && console_logged) { + static unsigned long last_print; + unsigned long now = jiffies; + + /* if we logged an MCE, reduce the polling interval */ + next_interval = max(next_interval/2, HZ/100); notify_user = 0; clear_bit(0, &console_logged); - printk(KERN_INFO "Machine check events logged\n"); + if (time_after_eq(now, last_print + (check_interval*HZ))) { + last_print = now; + printk(KERN_INFO "Machine check events logged\n"); + } + } else { + next_interval = min(next_interval*2, check_interval*HZ); } + + schedule_delayed_work(&mcheck_work, next_interval); } static __init int periodic_mcheck_init(void) { - if (check_interval) - schedule_delayed_work(&mcheck_work, check_interval*HZ); + next_interval = check_interval * HZ; + if (next_interval) + schedule_delayed_work(&mcheck_work, next_interval); return 0; } __initcall(periodic_mcheck_init); @@ -597,12 +612,13 @@ static int mce_resume(struct sys_device *dev) /* Reinit MCEs after user configuration changes */ static void mce_restart(void) { - if (check_interval) + if (next_interval) cancel_delayed_work(&mcheck_work); /* Timer race is harmless here */ on_each_cpu(mce_init, NULL, 1, 1); - if (check_interval) - schedule_delayed_work(&mcheck_work, check_interval*HZ); + next_interval = check_interval * HZ; + if (next_interval) + schedule_delayed_work(&mcheck_work, next_interval); } static struct sysdev_class mce_sysclass = { |
