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-rw-r--r--kernel/irq/Kconfig4
-rw-r--r--kernel/irq/cpuhotplug.c27
-rw-r--r--kernel/irq/internals.h9
-rw-r--r--kernel/irq/irqdesc.c65
-rw-r--r--kernel/irq/irqdomain.c5
-rw-r--r--kernel/irq/manage.c28
-rw-r--r--kernel/irq/proc.c9
-rw-r--r--kernel/irq/resend.c2
-rw-r--r--kernel/watchdog.c215
9 files changed, 311 insertions, 53 deletions
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 2531f3496ab6..529adb1f5859 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -108,6 +108,10 @@ config GENERIC_IRQ_MATRIX_ALLOCATOR
config GENERIC_IRQ_RESERVATION_MODE
bool
+# Snapshot for interrupt statistics
+config GENERIC_IRQ_STAT_SNAPSHOT
+ bool
+
# Support forced irq threading
config IRQ_FORCED_THREADING
bool
diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c
index 1ed2b1739363..75cadbc3c232 100644
--- a/kernel/irq/cpuhotplug.c
+++ b/kernel/irq/cpuhotplug.c
@@ -130,6 +130,22 @@ static bool migrate_one_irq(struct irq_desc *desc)
* CPU.
*/
err = irq_do_set_affinity(d, affinity, false);
+
+ /*
+ * If there are online CPUs in the affinity mask, but they have no
+ * vectors left to make the migration work, try to break the
+ * affinity by migrating to any online CPU.
+ */
+ if (err == -ENOSPC && !irqd_affinity_is_managed(d) && affinity != cpu_online_mask) {
+ pr_debug("IRQ%u: set affinity failed for %*pbl, re-try with online CPUs\n",
+ d->irq, cpumask_pr_args(affinity));
+
+ affinity = cpu_online_mask;
+ brokeaff = true;
+
+ err = irq_do_set_affinity(d, affinity, false);
+ }
+
if (err) {
pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n",
d->irq, err);
@@ -195,10 +211,15 @@ static void irq_restore_affinity_of_irq(struct irq_desc *desc, unsigned int cpu)
!irq_data_get_irq_chip(data) || !cpumask_test_cpu(cpu, affinity))
return;
- if (irqd_is_managed_and_shutdown(data)) {
- irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
+ /*
+ * Don't restore suspended interrupts here when a system comes back
+ * from S3. They are reenabled via resume_device_irqs().
+ */
+ if (desc->istate & IRQS_SUSPENDED)
return;
- }
+
+ if (irqd_is_managed_and_shutdown(data))
+ irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
/*
* If the interrupt can only be directed to a single target
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index bcc7f21db9ee..ed28059e9849 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -98,6 +98,8 @@ extern void mask_irq(struct irq_desc *desc);
extern void unmask_irq(struct irq_desc *desc);
extern void unmask_threaded_irq(struct irq_desc *desc);
+extern unsigned int kstat_irqs_desc(struct irq_desc *desc, const struct cpumask *cpumask);
+
#ifdef CONFIG_SPARSE_IRQ
static inline void irq_mark_irq(unsigned int irq) { }
#else
@@ -258,7 +260,7 @@ static inline void irq_state_set_masked(struct irq_desc *desc)
static inline void __kstat_incr_irqs_this_cpu(struct irq_desc *desc)
{
- __this_cpu_inc(*desc->kstat_irqs);
+ __this_cpu_inc(desc->kstat_irqs->cnt);
__this_cpu_inc(kstat.irqs_sum);
}
@@ -278,6 +280,11 @@ static inline int irq_desc_is_chained(struct irq_desc *desc)
return (desc->action && desc->action == &chained_action);
}
+static inline bool irq_is_nmi(struct irq_desc *desc)
+{
+ return desc->istate & IRQS_NMI;
+}
+
#ifdef CONFIG_PM_SLEEP
bool irq_pm_check_wakeup(struct irq_desc *desc);
void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action);
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 4c6b32318ce3..88ac3652fcf2 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -134,7 +134,7 @@ static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
desc->name = NULL;
desc->owner = owner;
for_each_possible_cpu(cpu)
- *per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
+ *per_cpu_ptr(desc->kstat_irqs, cpu) = (struct irqstat) { };
desc_smp_init(desc, node, affinity);
}
@@ -186,7 +186,7 @@ static int init_desc(struct irq_desc *desc, int irq, int node,
const struct cpumask *affinity,
struct module *owner)
{
- desc->kstat_irqs = alloc_percpu(unsigned int);
+ desc->kstat_irqs = alloc_percpu(struct irqstat);
if (!desc->kstat_irqs)
return -ENOMEM;
@@ -911,10 +911,7 @@ int irq_set_percpu_devid_partition(unsigned int irq,
{
struct irq_desc *desc = irq_to_desc(irq);
- if (!desc)
- return -EINVAL;
-
- if (desc->percpu_enabled)
+ if (!desc || desc->percpu_enabled)
return -EINVAL;
desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
@@ -922,10 +919,7 @@ int irq_set_percpu_devid_partition(unsigned int irq,
if (!desc->percpu_enabled)
return -ENOMEM;
- if (affinity)
- desc->percpu_affinity = affinity;
- else
- desc->percpu_affinity = cpu_possible_mask;
+ desc->percpu_affinity = affinity ? : cpu_possible_mask;
irq_set_percpu_devid_flags(irq);
return 0;
@@ -968,33 +962,58 @@ unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
{
struct irq_desc *desc = irq_to_desc(irq);
- return desc && desc->kstat_irqs ?
- *per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
+ return desc && desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, cpu) : 0;
}
-static bool irq_is_nmi(struct irq_desc *desc)
+unsigned int kstat_irqs_desc(struct irq_desc *desc, const struct cpumask *cpumask)
{
- return desc->istate & IRQS_NMI;
-}
-
-static unsigned int kstat_irqs(unsigned int irq)
-{
- struct irq_desc *desc = irq_to_desc(irq);
unsigned int sum = 0;
int cpu;
- if (!desc || !desc->kstat_irqs)
- return 0;
if (!irq_settings_is_per_cpu_devid(desc) &&
!irq_settings_is_per_cpu(desc) &&
!irq_is_nmi(desc))
return data_race(desc->tot_count);
- for_each_possible_cpu(cpu)
- sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
+ for_each_cpu(cpu, cpumask)
+ sum += data_race(per_cpu(desc->kstat_irqs->cnt, cpu));
return sum;
}
+static unsigned int kstat_irqs(unsigned int irq)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+
+ if (!desc || !desc->kstat_irqs)
+ return 0;
+ return kstat_irqs_desc(desc, cpu_possible_mask);
+}
+
+#ifdef CONFIG_GENERIC_IRQ_STAT_SNAPSHOT
+
+void kstat_snapshot_irqs(void)
+{
+ struct irq_desc *desc;
+ unsigned int irq;
+
+ for_each_irq_desc(irq, desc) {
+ if (!desc->kstat_irqs)
+ continue;
+ this_cpu_write(desc->kstat_irqs->ref, this_cpu_read(desc->kstat_irqs->cnt));
+ }
+}
+
+unsigned int kstat_get_irq_since_snapshot(unsigned int irq)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+
+ if (!desc || !desc->kstat_irqs)
+ return 0;
+ return this_cpu_read(desc->kstat_irqs->cnt) - this_cpu_read(desc->kstat_irqs->ref);
+}
+
+#endif
+
/**
* kstat_irqs_usr - Get the statistics for an interrupt from thread context
* @irq: The interrupt number
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 3dd1c871e091..aadc8891cc16 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -909,10 +909,11 @@ EXPORT_SYMBOL_GPL(irq_create_of_mapping);
*/
void irq_dispose_mapping(unsigned int virq)
{
- struct irq_data *irq_data = irq_get_irq_data(virq);
+ struct irq_data *irq_data;
struct irq_domain *domain;
- if (!virq || !irq_data)
+ irq_data = virq ? irq_get_irq_data(virq) : NULL;
+ if (!irq_data)
return;
domain = irq_data->domain;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index bf9ae8a8686f..71b0fc2d0aea 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -564,7 +564,7 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
/* The release function is promised process context */
might_sleep();
- if (!desc || desc->istate & IRQS_NMI)
+ if (!desc || irq_is_nmi(desc))
return -EINVAL;
/* Complete initialisation of *notify */
@@ -800,10 +800,14 @@ void __enable_irq(struct irq_desc *desc)
irq_settings_set_noprobe(desc);
/*
* Call irq_startup() not irq_enable() here because the
- * interrupt might be marked NOAUTOEN. So irq_startup()
- * needs to be invoked when it gets enabled the first
- * time. If it was already started up, then irq_startup()
- * will invoke irq_enable() under the hood.
+ * interrupt might be marked NOAUTOEN so irq_startup()
+ * needs to be invoked when it gets enabled the first time.
+ * This is also required when __enable_irq() is invoked for
+ * a managed and shutdown interrupt from the S3 resume
+ * path.
+ *
+ * If it was already started up, then irq_startup() will
+ * invoke irq_enable() under the hood.
*/
irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
break;
@@ -898,7 +902,7 @@ int irq_set_irq_wake(unsigned int irq, unsigned int on)
return -EINVAL;
/* Don't use NMIs as wake up interrupts please */
- if (desc->istate & IRQS_NMI) {
+ if (irq_is_nmi(desc)) {
ret = -EINVAL;
goto out_unlock;
}
@@ -1624,7 +1628,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
*/
unsigned int oldtype;
- if (desc->istate & IRQS_NMI) {
+ if (irq_is_nmi(desc)) {
pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
new->name, irq, desc->irq_data.chip->name);
ret = -EINVAL;
@@ -2082,7 +2086,7 @@ const void *free_nmi(unsigned int irq, void *dev_id)
unsigned long flags;
const void *devname;
- if (!desc || WARN_ON(!(desc->istate & IRQS_NMI)))
+ if (!desc || WARN_ON(!irq_is_nmi(desc)))
return NULL;
if (WARN_ON(irq_settings_is_per_cpu_devid(desc)))
@@ -2548,7 +2552,7 @@ void free_percpu_nmi(unsigned int irq, void __percpu *dev_id)
if (!desc || !irq_settings_is_per_cpu_devid(desc))
return;
- if (WARN_ON(!(desc->istate & IRQS_NMI)))
+ if (WARN_ON(!irq_is_nmi(desc)))
return;
kfree(__free_percpu_irq(irq, dev_id));
@@ -2684,7 +2688,7 @@ int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
return -EINVAL;
/* The line cannot already be NMI */
- if (desc->istate & IRQS_NMI)
+ if (irq_is_nmi(desc))
return -EINVAL;
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
@@ -2745,7 +2749,7 @@ int prepare_percpu_nmi(unsigned int irq)
if (!desc)
return -EINVAL;
- if (WARN(!(desc->istate & IRQS_NMI),
+ if (WARN(!irq_is_nmi(desc),
KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
irq)) {
ret = -EINVAL;
@@ -2787,7 +2791,7 @@ void teardown_percpu_nmi(unsigned int irq)
if (!desc)
return;
- if (WARN_ON(!(desc->istate & IRQS_NMI)))
+ if (WARN_ON(!irq_is_nmi(desc)))
goto out;
irq_nmi_teardown(desc);
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 623b8136e9af..5c320c3f10a7 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -488,18 +488,15 @@ int show_interrupts(struct seq_file *p, void *v)
if (!desc || irq_settings_is_hidden(desc))
goto outsparse;
- if (desc->kstat_irqs) {
- for_each_online_cpu(j)
- any_count |= data_race(*per_cpu_ptr(desc->kstat_irqs, j));
- }
+ if (desc->kstat_irqs)
+ any_count = kstat_irqs_desc(desc, cpu_online_mask);
if ((!desc->action || irq_desc_is_chained(desc)) && !any_count)
goto outsparse;
seq_printf(p, "%*d: ", prec, i);
for_each_online_cpu(j)
- seq_printf(p, "%10u ", desc->kstat_irqs ?
- *per_cpu_ptr(desc->kstat_irqs, j) : 0);
+ seq_printf(p, "%10u ", desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, j) : 0);
raw_spin_lock_irqsave(&desc->lock, flags);
if (desc->irq_data.chip) {
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c
index 5f2c66860ac6..b07a2d732ffb 100644
--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -190,7 +190,7 @@ int irq_inject_interrupt(unsigned int irq)
* - not NMI type
* - activated
*/
- if ((desc->istate & IRQS_NMI) || !irqd_is_activated(&desc->irq_data))
+ if (irq_is_nmi(desc) || !irqd_is_activated(&desc->irq_data))
err = -EINVAL;
else
err = check_irq_resend(desc, true);
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index d7b2125503af..d12ff74889ed 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -12,20 +12,25 @@
#define pr_fmt(fmt) "watchdog: " fmt
-#include <linux/mm.h>
#include <linux/cpu.h>
-#include <linux/nmi.h>
#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
+#include <linux/kernel_stat.h>
+#include <linux/kvm_para.h>
+#include <linux/math64.h>
+#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/nmi.h>
+#include <linux/stop_machine.h>
#include <linux/sysctl.h>
#include <linux/tick.h>
+
#include <linux/sched/clock.h>
#include <linux/sched/debug.h>
#include <linux/sched/isolation.h>
-#include <linux/stop_machine.h>
#include <asm/irq_regs.h>
-#include <linux/kvm_para.h>
static DEFINE_MUTEX(watchdog_mutex);
@@ -35,6 +40,8 @@ static DEFINE_MUTEX(watchdog_mutex);
# define WATCHDOG_HARDLOCKUP_DEFAULT 0
#endif
+#define NUM_SAMPLE_PERIODS 5
+
unsigned long __read_mostly watchdog_enabled;
int __read_mostly watchdog_user_enabled = 1;
static int __read_mostly watchdog_hardlockup_user_enabled = WATCHDOG_HARDLOCKUP_DEFAULT;
@@ -333,6 +340,188 @@ __setup("watchdog_thresh=", watchdog_thresh_setup);
static void __lockup_detector_cleanup(void);
+#ifdef CONFIG_SOFTLOCKUP_DETECTOR_INTR_STORM
+enum stats_per_group {
+ STATS_SYSTEM,
+ STATS_SOFTIRQ,
+ STATS_HARDIRQ,
+ STATS_IDLE,
+ NUM_STATS_PER_GROUP,
+};
+
+static const enum cpu_usage_stat tracked_stats[NUM_STATS_PER_GROUP] = {
+ CPUTIME_SYSTEM,
+ CPUTIME_SOFTIRQ,
+ CPUTIME_IRQ,
+ CPUTIME_IDLE,
+};
+
+static DEFINE_PER_CPU(u16, cpustat_old[NUM_STATS_PER_GROUP]);
+static DEFINE_PER_CPU(u8, cpustat_util[NUM_SAMPLE_PERIODS][NUM_STATS_PER_GROUP]);
+static DEFINE_PER_CPU(u8, cpustat_tail);
+
+/*
+ * We don't need nanosecond resolution. A granularity of 16ms is
+ * sufficient for our precision, allowing us to use u16 to store
+ * cpustats, which will roll over roughly every ~1000 seconds.
+ * 2^24 ~= 16 * 10^6
+ */
+static u16 get_16bit_precision(u64 data_ns)
+{
+ return data_ns >> 24LL; /* 2^24ns ~= 16.8ms */
+}
+
+static void update_cpustat(void)
+{
+ int i;
+ u8 util;
+ u16 old_stat, new_stat;
+ struct kernel_cpustat kcpustat;
+ u64 *cpustat = kcpustat.cpustat;
+ u8 tail = __this_cpu_read(cpustat_tail);
+ u16 sample_period_16 = get_16bit_precision(sample_period);
+
+ kcpustat_cpu_fetch(&kcpustat, smp_processor_id());
+
+ for (i = 0; i < NUM_STATS_PER_GROUP; i++) {
+ old_stat = __this_cpu_read(cpustat_old[i]);
+ new_stat = get_16bit_precision(cpustat[tracked_stats[i]]);
+ util = DIV_ROUND_UP(100 * (new_stat - old_stat), sample_period_16);
+ __this_cpu_write(cpustat_util[tail][i], util);
+ __this_cpu_write(cpustat_old[i], new_stat);
+ }
+
+ __this_cpu_write(cpustat_tail, (tail + 1) % NUM_SAMPLE_PERIODS);
+}
+
+static void print_cpustat(void)
+{
+ int i, group;
+ u8 tail = __this_cpu_read(cpustat_tail);
+ u64 sample_period_second = sample_period;
+
+ do_div(sample_period_second, NSEC_PER_SEC);
+
+ /*
+ * Outputting the "watchdog" prefix on every line is redundant and not
+ * concise, and the original alarm information is sufficient for
+ * positioning in logs, hence here printk() is used instead of pr_crit().
+ */
+ printk(KERN_CRIT "CPU#%d Utilization every %llus during lockup:\n",
+ smp_processor_id(), sample_period_second);
+
+ for (i = 0; i < NUM_SAMPLE_PERIODS; i++) {
+ group = (tail + i) % NUM_SAMPLE_PERIODS;
+ printk(KERN_CRIT "\t#%d: %3u%% system,\t%3u%% softirq,\t"
+ "%3u%% hardirq,\t%3u%% idle\n", i + 1,
+ __this_cpu_read(cpustat_util[group][STATS_SYSTEM]),
+ __this_cpu_read(cpustat_util[group][STATS_SOFTIRQ]),
+ __this_cpu_read(cpustat_util[group][STATS_HARDIRQ]),
+ __this_cpu_read(cpustat_util[group][STATS_IDLE]));
+ }
+}
+
+#define HARDIRQ_PERCENT_THRESH 50
+#define NUM_HARDIRQ_REPORT 5
+struct irq_counts {
+ int irq;
+ u32 counts;
+};
+
+static DEFINE_PER_CPU(bool, snapshot_taken);
+
+/* Tabulate the most frequent interrupts. */
+static void tabulate_irq_count(struct irq_counts *irq_counts, int irq, u32 counts, int rank)
+{
+ int i;
+ struct irq_counts new_count = {irq, counts};
+
+ for (i = 0; i < rank; i++) {
+ if (counts > irq_counts[i].counts)
+ swap(new_count, irq_counts[i]);
+ }
+}
+
+/*
+ * If the hardirq time exceeds HARDIRQ_PERCENT_THRESH% of the sample_period,
+ * then the cause of softlockup might be interrupt storm. In this case, it
+ * would be useful to start interrupt counting.
+ */
+static bool need_counting_irqs(void)
+{
+ u8 util;
+ int tail = __this_cpu_read(cpustat_tail);
+
+ tail = (tail + NUM_HARDIRQ_REPORT - 1) % NUM_HARDIRQ_REPORT;
+ util = __this_cpu_read(cpustat_util[tail][STATS_HARDIRQ]);
+ return util > HARDIRQ_PERCENT_THRESH;
+}
+
+static void start_counting_irqs(void)
+{
+ if (!__this_cpu_read(snapshot_taken)) {
+ kstat_snapshot_irqs();
+ __this_cpu_write(snapshot_taken, true);
+ }
+}
+
+static void stop_counting_irqs(void)
+{
+ __this_cpu_write(snapshot_taken, false);
+}
+
+static void print_irq_counts(void)
+{
+ unsigned int i, count;
+ struct irq_counts irq_counts_sorted[NUM_HARDIRQ_REPORT] = {
+ {-1, 0}, {-1, 0}, {-1, 0}, {-1, 0}, {-1, 0}
+ };
+
+ if (__this_cpu_read(snapshot_taken)) {
+ for_each_active_irq(i) {
+ count = kstat_get_irq_since_snapshot(i);
+ tabulate_irq_count(irq_counts_sorted, i, count, NUM_HARDIRQ_REPORT);
+ }
+
+ /*
+ * Outputting the "watchdog" prefix on every line is redundant and not
+ * concise, and the original alarm information is sufficient for
+ * positioning in logs, hence here printk() is used instead of pr_crit().
+ */
+ printk(KERN_CRIT "CPU#%d Detect HardIRQ Time exceeds %d%%. Most frequent HardIRQs:\n",
+ smp_processor_id(), HARDIRQ_PERCENT_THRESH);
+
+ for (i = 0; i < NUM_HARDIRQ_REPORT; i++) {
+ if (irq_counts_sorted[i].irq == -1)
+ break;
+
+ printk(KERN_CRIT "\t#%u: %-10u\tirq#%d\n",
+ i + 1, irq_counts_sorted[i].counts,
+ irq_counts_sorted[i].irq);
+ }
+
+ /*
+ * If the hardirq time is less than HARDIRQ_PERCENT_THRESH% in the last
+ * sample_period, then we suspect the interrupt storm might be subsiding.
+ */
+ if (!need_counting_irqs())
+ stop_counting_irqs();
+ }
+}
+
+static void report_cpu_status(void)
+{
+ print_cpustat();
+ print_irq_counts();
+}
+#else
+static inline void update_cpustat(void) { }
+static inline void report_cpu_status(void) { }
+static inline bool need_counting_irqs(void) { return false; }
+static inline void start_counting_irqs(void) { }
+static inline void stop_counting_irqs(void) { }
+#endif
+
/*
* Hard-lockup warnings should be triggered after just a few seconds. Soft-
* lockups can have false positives under extreme conditions. So we generally
@@ -364,7 +553,7 @@ static void set_sample_period(void)
* and hard thresholds) to increment before the
* hardlockup detector generates a warning
*/
- sample_period = get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 5);
+ sample_period = get_softlockup_thresh() * ((u64)NSEC_PER_SEC / NUM_SAMPLE_PERIODS);
watchdog_update_hrtimer_threshold(sample_period);
}
@@ -434,6 +623,18 @@ static int is_softlockup(unsigned long touch_ts,
unsigned long now)
{
if ((watchdog_enabled & WATCHDOG_SOFTOCKUP_ENABLED) && watchdog_thresh) {
+ /*
+ * If period_ts has not been updated during a sample_period, then
+ * in the subsequent few sample_periods, period_ts might also not
+ * be updated, which could indicate a potential softlockup. In
+ * this case, if we suspect the cause of the potential softlockup
+ * might be interrupt storm, then we need to count the interrupts
+ * to find which interrupt is storming.
+ */
+ if (time_after_eq(now, period_ts + get_softlockup_thresh() / NUM_SAMPLE_PERIODS) &&
+ need_counting_irqs())
+ start_counting_irqs();
+
/* Warn about unreasonable delays. */
if (time_after(now, period_ts + get_softlockup_thresh()))
return now - touch_ts;
@@ -456,6 +657,7 @@ static DEFINE_PER_CPU(struct cpu_stop_work, softlockup_stop_work);
static int softlockup_fn(void *data)
{
update_touch_ts();
+ stop_counting_irqs();
complete(this_cpu_ptr(&softlockup_completion));
return 0;
@@ -504,6 +706,8 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
*/
period_ts = READ_ONCE(*this_cpu_ptr(&watchdog_report_ts));
+ update_cpustat();
+
/* Reset the interval when touched by known problematic code. */
if (period_ts == SOFTLOCKUP_DELAY_REPORT) {
if (unlikely(__this_cpu_read(softlockup_touch_sync))) {
@@ -539,6 +743,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
pr_emerg("BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
smp_processor_id(), duration,
current->comm, task_pid_nr(current));
+ report_cpu_status();
print_modules();
print_irqtrace_events(current);
if (regs)
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2025-01-02 19:21:43 +0000