/*
* Setup the hardware configuration for a given attr_type
*/
-static int __hw_perf_event_init(struct perf_event *event)
+static int __x86_pmu_event_init(struct perf_event *event)
{
int err;
}
}
-void hw_perf_disable(void)
+static void x86_pmu_disable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
}
}
-static const struct pmu pmu;
+static struct pmu pmu;
static inline int is_x86_event(struct perf_event *event)
{
hwc->last_tag == cpuc->tags[i];
}
-static int x86_pmu_start(struct perf_event *event);
-static void x86_pmu_stop(struct perf_event *event);
+static void x86_pmu_start(struct perf_event *event, int flags);
+static void x86_pmu_stop(struct perf_event *event, int flags);
-void hw_perf_enable(void)
+static void x86_pmu_enable(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct perf_event *event;
match_prev_assignment(hwc, cpuc, i))
continue;
- x86_pmu_stop(event);
+ /*
+ * Ensure we don't accidentally enable a stopped
+ * counter simply because we rescheduled.
+ */
+ if (hwc->state & PERF_HES_STOPPED)
+ hwc->state |= PERF_HES_ARCH;
+
+ x86_pmu_stop(event, PERF_EF_UPDATE);
}
for (i = 0; i < cpuc->n_events; i++) {
else if (i < n_running)
continue;
- x86_pmu_start(event);
+ if (hwc->state & PERF_HES_ARCH)
+ continue;
+
+ x86_pmu_start(event, PERF_EF_RELOAD);
}
cpuc->n_added = 0;
perf_events_lapic_init();
}
/*
- * activate a single event
+ * Add a single event to the PMU.
*
* The event is added to the group of enabled events
* but only if it can be scehduled with existing events.
- *
- * Called with PMU disabled. If successful and return value 1,
- * then guaranteed to call perf_enable() and hw_perf_enable()
*/
-static int x86_pmu_enable(struct perf_event *event)
+static int x86_pmu_add(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc;
hwc = &event->hw;
+ perf_pmu_disable(event->pmu);
n0 = cpuc->n_events;
- n = collect_events(cpuc, event, false);
- if (n < 0)
- return n;
+ ret = n = collect_events(cpuc, event, false);
+ if (ret < 0)
+ goto out;
+
+ hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+ if (!(flags & PERF_EF_START))
+ hwc->state |= PERF_HES_ARCH;
/*
* If group events scheduling transaction was started,
* skip the schedulability test here, it will be peformed
- * at commit time(->commit_txn) as a whole
+ * at commit time (->commit_txn) as a whole
*/
if (cpuc->group_flag & PERF_EVENT_TXN)
- goto out;
+ goto done_collect;
ret = x86_pmu.schedule_events(cpuc, n, assign);
if (ret)
- return ret;
+ goto out;
/*
* copy new assignment, now we know it is possible
* will be used by hw_perf_enable()
*/
memcpy(cpuc->assign, assign, n*sizeof(int));
-out:
+done_collect:
cpuc->n_events = n;
cpuc->n_added += n - n0;
cpuc->n_txn += n - n0;
- return 0;
+ ret = 0;
+out:
+ perf_pmu_enable(event->pmu);
+ return ret;
}
-static int x86_pmu_start(struct perf_event *event)
+static void x86_pmu_start(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
int idx = event->hw.idx;
- if (idx == -1)
- return -EAGAIN;
+ if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
+ return;
+
+ if (WARN_ON_ONCE(idx == -1))
+ return;
+
+ if (flags & PERF_EF_RELOAD) {
+ WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+ x86_perf_event_set_period(event);
+ }
+
+ event->hw.state = 0;
- x86_perf_event_set_period(event);
cpuc->events[idx] = event;
__set_bit(idx, cpuc->active_mask);
x86_pmu.enable(event);
perf_event_update_userpage(event);
-
- return 0;
-}
-
-static void x86_pmu_unthrottle(struct perf_event *event)
-{
- int ret = x86_pmu_start(event);
- WARN_ON_ONCE(ret);
}
void perf_event_print_debug(void)
local_irq_restore(flags);
}
-static void x86_pmu_stop(struct perf_event *event)
+static void x86_pmu_stop(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
- int idx = hwc->idx;
-
- if (!__test_and_clear_bit(idx, cpuc->active_mask))
- return;
-
- x86_pmu.disable(event);
- /*
- * Drain the remaining delta count out of a event
- * that we are disabling:
- */
- x86_perf_event_update(event);
+ if (__test_and_clear_bit(hwc->idx, cpuc->active_mask)) {
+ x86_pmu.disable(event);
+ cpuc->events[hwc->idx] = NULL;
+ WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
+ hwc->state |= PERF_HES_STOPPED;
+ }
- cpuc->events[idx] = NULL;
+ if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
+ /*
+ * Drain the remaining delta count out of a event
+ * that we are disabling:
+ */
+ x86_perf_event_update(event);
+ hwc->state |= PERF_HES_UPTODATE;
+ }
}
-static void x86_pmu_disable(struct perf_event *event)
+static void x86_pmu_del(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
int i;
if (cpuc->group_flag & PERF_EVENT_TXN)
return;
- x86_pmu_stop(event);
+ x86_pmu_stop(event, PERF_EF_UPDATE);
for (i = 0; i < cpuc->n_events; i++) {
if (event == cpuc->event_list[i]) {
/*
* event overflow
*/
- handled = 1;
+ handled++;
data.period = event->hw.last_period;
if (!x86_perf_event_set_period(event))
continue;
if (perf_event_overflow(event, 1, &data, regs))
- x86_pmu_stop(event);
+ x86_pmu_stop(event, 0);
}
if (handled)
apic_write(APIC_LVTPC, APIC_DM_NMI);
}
+struct pmu_nmi_state {
+ unsigned int marked;
+ int handled;
+};
+
+static DEFINE_PER_CPU(struct pmu_nmi_state, pmu_nmi);
+
static int __kprobes
perf_event_nmi_handler(struct notifier_block *self,
unsigned long cmd, void *__args)
{
struct die_args *args = __args;
- struct pt_regs *regs;
+ unsigned int this_nmi;
+ int handled;
if (!atomic_read(&active_events))
return NOTIFY_DONE;
case DIE_NMI:
case DIE_NMI_IPI:
break;
-
+ case DIE_NMIUNKNOWN:
+ this_nmi = percpu_read(irq_stat.__nmi_count);
+ if (this_nmi != __get_cpu_var(pmu_nmi).marked)
+ /* let the kernel handle the unknown nmi */
+ return NOTIFY_DONE;
+ /*
+ * This one is a PMU back-to-back nmi. Two events
+ * trigger 'simultaneously' raising two back-to-back
+ * NMIs. If the first NMI handles both, the latter
+ * will be empty and daze the CPU. So, we drop it to
+ * avoid false-positive 'unknown nmi' messages.
+ */
+ return NOTIFY_STOP;
default:
return NOTIFY_DONE;
}
- regs = args->regs;
-
apic_write(APIC_LVTPC, APIC_DM_NMI);
- /*
- * Can't rely on the handled return value to say it was our NMI, two
- * events could trigger 'simultaneously' raising two back-to-back NMIs.
- *
- * If the first NMI handles both, the latter will be empty and daze
- * the CPU.
- */
- x86_pmu.handle_irq(regs);
+
+ handled = x86_pmu.handle_irq(args->regs);
+ if (!handled)
+ return NOTIFY_DONE;
+
+ this_nmi = percpu_read(irq_stat.__nmi_count);
+ if ((handled > 1) ||
+ /* the next nmi could be a back-to-back nmi */
+ ((__get_cpu_var(pmu_nmi).marked == this_nmi) &&
+ (__get_cpu_var(pmu_nmi).handled > 1))) {
+ /*
+ * We could have two subsequent back-to-back nmis: The
+ * first handles more than one counter, the 2nd
+ * handles only one counter and the 3rd handles no
+ * counter.
+ *
+ * This is the 2nd nmi because the previous was
+ * handling more than one counter. We will mark the
+ * next (3rd) and then drop it if unhandled.
+ */
+ __get_cpu_var(pmu_nmi).marked = this_nmi + 1;
+ __get_cpu_var(pmu_nmi).handled = handled;
+ }
return NOTIFY_STOP;
}
pr_info("... fixed-purpose events: %d\n", x86_pmu.num_counters_fixed);
pr_info("... event mask: %016Lx\n", x86_pmu.intel_ctrl);
+ perf_pmu_register(&pmu);
perf_cpu_notifier(x86_pmu_notifier);
}
* Set the flag to make pmu::enable() not perform the
* schedulability test, it will be performed at commit time
*/
-static void x86_pmu_start_txn(const struct pmu *pmu)
+static void x86_pmu_start_txn(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ perf_pmu_disable(pmu);
cpuc->group_flag |= PERF_EVENT_TXN;
cpuc->n_txn = 0;
}
* Clear the flag and pmu::enable() will perform the
* schedulability test.
*/
-static void x86_pmu_cancel_txn(const struct pmu *pmu)
+static void x86_pmu_cancel_txn(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
*/
cpuc->n_added -= cpuc->n_txn;
cpuc->n_events -= cpuc->n_txn;
+ perf_pmu_enable(pmu);
}
/*
* Perform the group schedulability test as a whole
* Return 0 if success
*/
-static int x86_pmu_commit_txn(const struct pmu *pmu)
+static int x86_pmu_commit_txn(struct pmu *pmu)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
int assign[X86_PMC_IDX_MAX];
memcpy(cpuc->assign, assign, n*sizeof(int));
cpuc->group_flag &= ~PERF_EVENT_TXN;
-
+ perf_pmu_enable(pmu);
return 0;
}
-static const struct pmu pmu = {
- .enable = x86_pmu_enable,
- .disable = x86_pmu_disable,
- .start = x86_pmu_start,
- .stop = x86_pmu_stop,
- .read = x86_pmu_read,
- .unthrottle = x86_pmu_unthrottle,
- .start_txn = x86_pmu_start_txn,
- .cancel_txn = x86_pmu_cancel_txn,
- .commit_txn = x86_pmu_commit_txn,
-};
-
/*
* validate that we can schedule this event
*/
return ret;
}
-const struct pmu *hw_perf_event_init(struct perf_event *event)
+int x86_pmu_event_init(struct perf_event *event)
{
- const struct pmu *tmp;
+ struct pmu *tmp;
int err;
- err = __hw_perf_event_init(event);
+ switch (event->attr.type) {
+ case PERF_TYPE_RAW:
+ case PERF_TYPE_HARDWARE:
+ case PERF_TYPE_HW_CACHE:
+ break;
+
+ default:
+ return -ENOENT;
+ }
+
+ err = __x86_pmu_event_init(event);
if (!err) {
/*
* we temporarily connect event to its pmu
if (err) {
if (event->destroy)
event->destroy(event);
- return ERR_PTR(err);
}
- return &pmu;
+ return err;
}
+static struct pmu pmu = {
+ .pmu_enable = x86_pmu_enable,
+ .pmu_disable = x86_pmu_disable,
+
+ .event_init = x86_pmu_event_init,
+
+ .add = x86_pmu_add,
+ .del = x86_pmu_del,
+ .start = x86_pmu_start,
+ .stop = x86_pmu_stop,
+ .read = x86_pmu_read,
+
+ .start_txn = x86_pmu_start_txn,
+ .cancel_txn = x86_pmu_cancel_txn,
+ .commit_txn = x86_pmu_commit_txn,
+};
+
/*
* callchain support
*/
-static DEFINE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry_nmi);
-
-
static void
backtrace_warning_symbol(void *data, char *msg, unsigned long symbol)
{
{
if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
/* TODO: We don't support guest os callchain now */
- return NULL;
+ return;
}
perf_callchain_store(entry, regs->ip);
if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
/* TODO: We don't support guest os callchain now */
- return NULL;
+ return;
}
fp = (void __user *)regs->bp;
projects / mv-sheeva.git / blobdiff