if (pebs == NULL)
return;
+ regs->flags &= ~PERF_EFLAGS_EXACT;
sample_type = event->attr.sample_type;
dsrc = sample_type & PERF_SAMPLE_DATA_SRC;
*/
*regs = *iregs;
regs->flags = pebs->flags;
- set_linear_ip(regs, pebs->ip);
if (sample_type & PERF_SAMPLE_REGS_INTR) {
regs->ax = pebs->ax;
#endif
}
- if (event->attr.precise_ip > 1 && x86_pmu.intel_cap.pebs_format >= 2) {
- regs->ip = pebs->real_ip;
- regs->flags |= PERF_EFLAGS_EXACT;
- } else if (event->attr.precise_ip > 1 && intel_pmu_pebs_fixup_ip(regs))
- regs->flags |= PERF_EFLAGS_EXACT;
- else
- regs->flags &= ~PERF_EFLAGS_EXACT;
+ if (event->attr.precise_ip > 1) {
+ /* Haswell and later have the eventing IP, so use it: */
+ if (x86_pmu.intel_cap.pebs_format >= 2) {
+ set_linear_ip(regs, pebs->real_ip);
+ regs->flags |= PERF_EFLAGS_EXACT;
+ } else {
+ /* Otherwise use PEBS off-by-1 IP: */
+ set_linear_ip(regs, pebs->ip);
+
+ /* ... and try to fix it up using the LBR entries: */
+ if (intel_pmu_pebs_fixup_ip(regs))
+ regs->flags |= PERF_EFLAGS_EXACT;
+ }
+ } else
+ set_linear_ip(regs, pebs->ip);
+
if ((sample_type & (PERF_SAMPLE_ADDR | PERF_SAMPLE_PHYS_ADDR)) &&
x86_pmu.intel_cap.pebs_format >= 1)
return NULL;
}
+void intel_pmu_auto_reload_read(struct perf_event *event)
+{
+ WARN_ON(!(event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD));
+
+ perf_pmu_disable(event->pmu);
+ intel_pmu_drain_pebs_buffer();
+ perf_pmu_enable(event->pmu);
+}
+
+/*
+ * Special variant of intel_pmu_save_and_restart() for auto-reload.
+ */
+static int
+intel_pmu_save_and_restart_reload(struct perf_event *event, int count)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ int shift = 64 - x86_pmu.cntval_bits;
+ u64 period = hwc->sample_period;
+ u64 prev_raw_count, new_raw_count;
+ s64 new, old;
+
+ WARN_ON(!period);
+
+ /*
+ * drain_pebs() only happens when the PMU is disabled.
+ */
+ WARN_ON(this_cpu_read(cpu_hw_events.enabled));
+
+ prev_raw_count = local64_read(&hwc->prev_count);
+ rdpmcl(hwc->event_base_rdpmc, new_raw_count);
+ local64_set(&hwc->prev_count, new_raw_count);
+
+ /*
+ * Since the counter increments a negative counter value and
+ * overflows on the sign switch, giving the interval:
+ *
+ * [-period, 0]
+ *
+ * the difference between two consequtive reads is:
+ *
+ * A) value2 - value1;
+ * when no overflows have happened in between,
+ *
+ * B) (0 - value1) + (value2 - (-period));
+ * when one overflow happened in between,
+ *
+ * C) (0 - value1) + (n - 1) * (period) + (value2 - (-period));
+ * when @n overflows happened in between.
+ *
+ * Here A) is the obvious difference, B) is the extension to the
+ * discrete interval, where the first term is to the top of the
+ * interval and the second term is from the bottom of the next
+ * interval and C) the extension to multiple intervals, where the
+ * middle term is the whole intervals covered.
+ *
+ * An equivalent of C, by reduction, is:
+ *
+ * value2 - value1 + n * period
+ */
+ new = ((s64)(new_raw_count << shift) >> shift);
+ old = ((s64)(prev_raw_count << shift) >> shift);
+ local64_add(new - old + count * period, &event->count);
+
+ perf_event_update_userpage(event);
+
+ return 0;
+}
+
static void __intel_pmu_pebs_event(struct perf_event *event,
struct pt_regs *iregs,
void *base, void *top,
int bit, int count)
{
+ struct hw_perf_event *hwc = &event->hw;
struct perf_sample_data data;
struct pt_regs regs;
void *at = get_next_pebs_record_by_bit(base, top, bit);
- if (!intel_pmu_save_and_restart(event) &&
- !(event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD))
+ if (hwc->flags & PERF_X86_EVENT_AUTO_RELOAD) {
+ /*
+ * Now, auto-reload is only enabled in fixed period mode.
+ * The reload value is always hwc->sample_period.
+ * May need to change it, if auto-reload is enabled in
+ * freq mode later.
+ */
+ intel_pmu_save_and_restart_reload(event, count);
+ } else if (!intel_pmu_save_and_restart(event))
return;
while (count > 1) {
return;
n = top - at;
- if (n <= 0)
+ if (n <= 0) {
+ if (event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD)
+ intel_pmu_save_and_restart_reload(event, 0);
return;
+ }
__intel_pmu_pebs_event(event, iregs, at, top, 0, n);
}
ds->pebs_index = ds->pebs_buffer_base;
- if (unlikely(base >= top))
+ if (unlikely(base >= top)) {
+ /*
+ * The drain_pebs() could be called twice in a short period
+ * for auto-reload event in pmu::read(). There are no
+ * overflows have happened in between.
+ * It needs to call intel_pmu_save_and_restart_reload() to
+ * update the event->count for this case.
+ */
+ for_each_set_bit(bit, (unsigned long *)&cpuc->pebs_enabled,
+ x86_pmu.max_pebs_events) {
+ event = cpuc->events[bit];
+ if (event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD)
+ intel_pmu_save_and_restart_reload(event, 0);
+ }
return;
+ }
for (at = base; at < top; at += x86_pmu.pebs_record_size) {
struct pebs_record_nhm *p = at;
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