static DEFINE_PER_CPU(unsigned long, mce_next_interval); /* in jiffies */
static DEFINE_PER_CPU(struct timer_list, mce_timer);
+static unsigned long mce_adjust_timer_default(unsigned long interval)
+{
+ return interval;
+}
+
+static unsigned long (*mce_adjust_timer)(unsigned long interval) =
+ mce_adjust_timer_default;
+
static void mce_timer_fn(unsigned long data)
{
struct timer_list *t = &__get_cpu_var(mce_timer);
if (mce_available(__this_cpu_ptr(&cpu_info))) {
machine_check_poll(MCP_TIMESTAMP,
&__get_cpu_var(mce_poll_banks));
+ mce_intel_cmci_poll();
}
/*
* polling interval, otherwise increase the polling interval.
*/
iv = __this_cpu_read(mce_next_interval);
- if (mce_notify_irq())
+ if (mce_notify_irq()) {
iv = max(iv / 2, (unsigned long) HZ/100);
- else
+ } else {
iv = min(iv * 2, round_jiffies_relative(check_interval * HZ));
+ iv = mce_adjust_timer(iv);
+ }
__this_cpu_write(mce_next_interval, iv);
+ /* Might have become 0 after CMCI storm subsided */
+ if (iv) {
+ t->expires = jiffies + iv;
+ add_timer_on(t, smp_processor_id());
+ }
+}
- t->expires = jiffies + iv;
- add_timer_on(t, smp_processor_id());
+/*
+ * Ensure that the timer is firing in @interval from now.
+ */
+void mce_timer_kick(unsigned long interval)
+{
+ struct timer_list *t = &__get_cpu_var(mce_timer);
+ unsigned long when = jiffies + interval;
+ unsigned long iv = __this_cpu_read(mce_next_interval);
+
+ if (timer_pending(t)) {
+ if (time_before(when, t->expires))
+ mod_timer_pinned(t, when);
+ } else {
+ t->expires = round_jiffies(when);
+ add_timer_on(t, smp_processor_id());
+ }
+ if (interval < iv)
+ __this_cpu_write(mce_next_interval, interval);
}
/* Must not be called in IRQ context where del_timer_sync() can deadlock */
switch (c->x86_vendor) {
case X86_VENDOR_INTEL:
mce_intel_feature_init(c);
+ mce_adjust_timer = mce_intel_adjust_timer;
break;
case X86_VENDOR_AMD:
mce_amd_feature_init(c);
}
}
-static void __mcheck_cpu_init_timer(void)
+static void mce_start_timer(unsigned int cpu, struct timer_list *t)
{
- struct timer_list *t = &__get_cpu_var(mce_timer);
- unsigned long iv = check_interval * HZ;
+ unsigned long iv = mce_adjust_timer(check_interval * HZ);
- setup_timer(t, mce_timer_fn, smp_processor_id());
+ __this_cpu_write(mce_next_interval, iv);
- if (mce_ignore_ce)
+ if (mce_ignore_ce || !iv)
return;
- __this_cpu_write(mce_next_interval, iv);
- if (!iv)
- return;
t->expires = round_jiffies(jiffies + iv);
add_timer_on(t, smp_processor_id());
}
+static void __mcheck_cpu_init_timer(void)
+{
+ struct timer_list *t = &__get_cpu_var(mce_timer);
+ unsigned int cpu = smp_processor_id();
+
+ setup_timer(t, mce_timer_fn, cpu);
+ mce_start_timer(cpu, t);
+}
+
/* Handle unconfigured int18 (should never happen) */
static void unexpected_machine_check(struct pt_regs *regs, long error_code)
{
unsigned int cpu = (unsigned long)hcpu;
struct timer_list *t = &per_cpu(mce_timer, cpu);
- switch (action) {
+ switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
mce_device_create(cpu);
if (threshold_cpu_callback)
threshold_cpu_callback(action, cpu);
break;
case CPU_DEAD:
- case CPU_DEAD_FROZEN:
if (threshold_cpu_callback)
threshold_cpu_callback(action, cpu);
mce_device_remove(cpu);
+ mce_intel_hcpu_update(cpu);
break;
case CPU_DOWN_PREPARE:
- case CPU_DOWN_PREPARE_FROZEN:
- del_timer_sync(t);
smp_call_function_single(cpu, mce_disable_cpu, &action, 1);
+ del_timer_sync(t);
break;
case CPU_DOWN_FAILED:
- case CPU_DOWN_FAILED_FROZEN:
- if (!mce_ignore_ce && check_interval) {
- t->expires = round_jiffies(jiffies +
- per_cpu(mce_next_interval, cpu));
- add_timer_on(t, cpu);
- }
smp_call_function_single(cpu, mce_reenable_cpu, &action, 1);
+ mce_start_timer(cpu, t);
break;
- case CPU_POST_DEAD:
+ }
+
+ if (action == CPU_POST_DEAD) {
/* intentionally ignoring frozen here */
cmci_rediscover(cpu);
- break;
}
+
return NOTIFY_OK;
}
#include <asm/msr.h>
#include <asm/mce.h>
+#include "mce-internal.h"
+
/*
* Support for Intel Correct Machine Check Interrupts. This allows
* the CPU to raise an interrupt when a corrected machine check happened.
*/
static DEFINE_RAW_SPINLOCK(cmci_discover_lock);
-#define CMCI_THRESHOLD 1
+#define CMCI_THRESHOLD 1
+#define CMCI_POLL_INTERVAL (30 * HZ)
+#define CMCI_STORM_INTERVAL (1 * HZ)
+#define CMCI_STORM_THRESHOLD 15
+
+static DEFINE_PER_CPU(unsigned long, cmci_time_stamp);
+static DEFINE_PER_CPU(unsigned int, cmci_storm_cnt);
+static DEFINE_PER_CPU(unsigned int, cmci_storm_state);
+
+enum {
+ CMCI_STORM_NONE,
+ CMCI_STORM_ACTIVE,
+ CMCI_STORM_SUBSIDED,
+};
+
+static atomic_t cmci_storm_on_cpus;
static int cmci_supported(int *banks)
{
return !!(cap & MCG_CMCI_P);
}
+void mce_intel_cmci_poll(void)
+{
+ if (__this_cpu_read(cmci_storm_state) == CMCI_STORM_NONE)
+ return;
+ machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
+}
+
+void mce_intel_hcpu_update(unsigned long cpu)
+{
+ if (per_cpu(cmci_storm_state, cpu) == CMCI_STORM_ACTIVE)
+ atomic_dec(&cmci_storm_on_cpus);
+
+ per_cpu(cmci_storm_state, cpu) = CMCI_STORM_NONE;
+}
+
+unsigned long mce_intel_adjust_timer(unsigned long interval)
+{
+ int r;
+
+ if (interval < CMCI_POLL_INTERVAL)
+ return interval;
+
+ switch (__this_cpu_read(cmci_storm_state)) {
+ case CMCI_STORM_ACTIVE:
+ /*
+ * We switch back to interrupt mode once the poll timer has
+ * silenced itself. That means no events recorded and the
+ * timer interval is back to our poll interval.
+ */
+ __this_cpu_write(cmci_storm_state, CMCI_STORM_SUBSIDED);
+ r = atomic_sub_return(1, &cmci_storm_on_cpus);
+ if (r == 0)
+ pr_notice("CMCI storm subsided: switching to interrupt mode\n");
+ /* FALLTHROUGH */
+
+ case CMCI_STORM_SUBSIDED:
+ /*
+ * We wait for all cpus to go back to SUBSIDED
+ * state. When that happens we switch back to
+ * interrupt mode.
+ */
+ if (!atomic_read(&cmci_storm_on_cpus)) {
+ __this_cpu_write(cmci_storm_state, CMCI_STORM_NONE);
+ cmci_reenable();
+ cmci_recheck();
+ }
+ return CMCI_POLL_INTERVAL;
+ default:
+ /*
+ * We have shiny weather. Let the poll do whatever it
+ * thinks.
+ */
+ return interval;
+ }
+}
+
+static bool cmci_storm_detect(void)
+{
+ unsigned int cnt = __this_cpu_read(cmci_storm_cnt);
+ unsigned long ts = __this_cpu_read(cmci_time_stamp);
+ unsigned long now = jiffies;
+ int r;
+
+ if (__this_cpu_read(cmci_storm_state) != CMCI_STORM_NONE)
+ return true;
+
+ if (time_before_eq(now, ts + CMCI_STORM_INTERVAL)) {
+ cnt++;
+ } else {
+ cnt = 1;
+ __this_cpu_write(cmci_time_stamp, now);
+ }
+ __this_cpu_write(cmci_storm_cnt, cnt);
+
+ if (cnt <= CMCI_STORM_THRESHOLD)
+ return false;
+
+ cmci_clear();
+ __this_cpu_write(cmci_storm_state, CMCI_STORM_ACTIVE);
+ r = atomic_add_return(1, &cmci_storm_on_cpus);
+ mce_timer_kick(CMCI_POLL_INTERVAL);
+
+ if (r == 1)
+ pr_notice("CMCI storm detected: switching to poll mode\n");
+ return true;
+}
+
/*
* The interrupt handler. This is called on every event.
* Just call the poller directly to log any events.
*/
static void intel_threshold_interrupt(void)
{
+ if (cmci_storm_detect())
+ return;
machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
mce_notify_irq();
}
-static void print_update(char *type, int *hdr, int num)
-{
- if (*hdr == 0)
- printk(KERN_INFO "CPU %d MCA banks", smp_processor_id());
- *hdr = 1;
- printk(KERN_CONT " %s:%d", type, num);
-}
-
/*
* Enable CMCI (Corrected Machine Check Interrupt) for available MCE banks
* on this CPU. Use the algorithm recommended in the SDM to discover shared
* banks.
*/
-static void cmci_discover(int banks, int boot)
+static void cmci_discover(int banks)
{
unsigned long *owned = (void *)&__get_cpu_var(mce_banks_owned);
unsigned long flags;
- int hdr = 0;
int i;
raw_spin_lock_irqsave(&cmci_discover_lock, flags);
/* Already owned by someone else? */
if (val & MCI_CTL2_CMCI_EN) {
- if (test_and_clear_bit(i, owned) && !boot)
- print_update("SHD", &hdr, i);
+ clear_bit(i, owned);
__clear_bit(i, __get_cpu_var(mce_poll_banks));
continue;
}
/* Did the enable bit stick? -- the bank supports CMCI */
if (val & MCI_CTL2_CMCI_EN) {
- if (!test_and_set_bit(i, owned) && !boot)
- print_update("CMCI", &hdr, i);
+ set_bit(i, owned);
__clear_bit(i, __get_cpu_var(mce_poll_banks));
} else {
WARN_ON(!test_bit(i, __get_cpu_var(mce_poll_banks)));
}
}
raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
- if (hdr)
- printk(KERN_CONT "\n");
}
/*
continue;
/* Recheck banks in case CPUs don't all have the same */
if (cmci_supported(&banks))
- cmci_discover(banks, 0);
+ cmci_discover(banks);
}
set_cpus_allowed_ptr(current, old);
{
int banks;
if (cmci_supported(&banks))
- cmci_discover(banks, 0);
+ cmci_discover(banks);
}
static void intel_init_cmci(void)
return;
mce_threshold_vector = intel_threshold_interrupt;
- cmci_discover(banks, 1);
+ cmci_discover(banks);
/*
* For CPU #0 this runs with still disabled APIC, but that's
* ok because only the vector is set up. We still do another
git.samba.org / sfrench / cifs-2.6.git / commitdiff