- Make sure the PEBS buffer is flushed before reprogramming the hardware

so that the correct record sizes are used
 
 - Update the sample size for AMD BRS events
 
 - Fix a confusion with using the same on-stack struct with different
   events in the event processing path
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Merge tag 'perf_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Borislav Petkov:

 - Make sure the PEBS buffer is flushed before reprogramming the
   hardware so that the correct record sizes are used

 - Update the sample size for AMD BRS events

 - Fix a confusion with using the same on-stack struct with different
   events in the event processing path

* tag 'perf_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/ds: Flush PEBS DS when changing PEBS_DATA_CFG
  perf/x86: Fix missing sample size update on AMD BRS
  perf/core: Fix perf_sample_data not properly initialized for different swevents in perf_tp_event()
This commit is contained in:
Linus Torvalds 2023-05-14 07:56:51 -07:00
commit ef21831c2e
4 changed files with 50 additions and 29 deletions

View File

@ -1703,10 +1703,8 @@ int x86_pmu_handle_irq(struct pt_regs *regs)
perf_sample_data_init(&data, 0, event->hw.last_period);
if (has_branch_stack(event)) {
data.br_stack = &cpuc->lbr_stack;
data.sample_flags |= PERF_SAMPLE_BRANCH_STACK;
}
if (has_branch_stack(event))
perf_sample_save_brstack(&data, event, &cpuc->lbr_stack);
if (perf_event_overflow(event, &data, regs))
x86_pmu_stop(event, 0);

View File

@ -1229,12 +1229,14 @@ pebs_update_state(bool needed_cb, struct cpu_hw_events *cpuc,
struct perf_event *event, bool add)
{
struct pmu *pmu = event->pmu;
/*
* Make sure we get updated with the first PEBS
* event. It will trigger also during removal, but
* that does not hurt:
*/
bool update = cpuc->n_pebs == 1;
if (cpuc->n_pebs == 1)
cpuc->pebs_data_cfg = PEBS_UPDATE_DS_SW;
if (needed_cb != pebs_needs_sched_cb(cpuc)) {
if (!needed_cb)
@ -1242,7 +1244,7 @@ pebs_update_state(bool needed_cb, struct cpu_hw_events *cpuc,
else
perf_sched_cb_dec(pmu);
update = true;
cpuc->pebs_data_cfg |= PEBS_UPDATE_DS_SW;
}
/*
@ -1252,24 +1254,13 @@ pebs_update_state(bool needed_cb, struct cpu_hw_events *cpuc,
if (x86_pmu.intel_cap.pebs_baseline && add) {
u64 pebs_data_cfg;
/* Clear pebs_data_cfg and pebs_record_size for first PEBS. */
if (cpuc->n_pebs == 1) {
cpuc->pebs_data_cfg = 0;
cpuc->pebs_record_size = sizeof(struct pebs_basic);
}
pebs_data_cfg = pebs_update_adaptive_cfg(event);
/* Update pebs_record_size if new event requires more data. */
if (pebs_data_cfg & ~cpuc->pebs_data_cfg) {
cpuc->pebs_data_cfg |= pebs_data_cfg;
adaptive_pebs_record_size_update();
update = true;
}
/*
* Be sure to update the thresholds when we change the record.
*/
if (pebs_data_cfg & ~cpuc->pebs_data_cfg)
cpuc->pebs_data_cfg |= pebs_data_cfg | PEBS_UPDATE_DS_SW;
}
if (update)
pebs_update_threshold(cpuc);
}
void intel_pmu_pebs_add(struct perf_event *event)
@ -1326,9 +1317,17 @@ static void intel_pmu_pebs_via_pt_enable(struct perf_event *event)
wrmsrl(base + idx, value);
}
static inline void intel_pmu_drain_large_pebs(struct cpu_hw_events *cpuc)
{
if (cpuc->n_pebs == cpuc->n_large_pebs &&
cpuc->n_pebs != cpuc->n_pebs_via_pt)
intel_pmu_drain_pebs_buffer();
}
void intel_pmu_pebs_enable(struct perf_event *event)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
u64 pebs_data_cfg = cpuc->pebs_data_cfg & ~PEBS_UPDATE_DS_SW;
struct hw_perf_event *hwc = &event->hw;
struct debug_store *ds = cpuc->ds;
unsigned int idx = hwc->idx;
@ -1344,11 +1343,22 @@ void intel_pmu_pebs_enable(struct perf_event *event)
if (x86_pmu.intel_cap.pebs_baseline) {
hwc->config |= ICL_EVENTSEL_ADAPTIVE;
if (cpuc->pebs_data_cfg != cpuc->active_pebs_data_cfg) {
wrmsrl(MSR_PEBS_DATA_CFG, cpuc->pebs_data_cfg);
cpuc->active_pebs_data_cfg = cpuc->pebs_data_cfg;
if (pebs_data_cfg != cpuc->active_pebs_data_cfg) {
/*
* drain_pebs() assumes uniform record size;
* hence we need to drain when changing said
* size.
*/
intel_pmu_drain_large_pebs(cpuc);
adaptive_pebs_record_size_update();
wrmsrl(MSR_PEBS_DATA_CFG, pebs_data_cfg);
cpuc->active_pebs_data_cfg = pebs_data_cfg;
}
}
if (cpuc->pebs_data_cfg & PEBS_UPDATE_DS_SW) {
cpuc->pebs_data_cfg = pebs_data_cfg;
pebs_update_threshold(cpuc);
}
if (idx >= INTEL_PMC_IDX_FIXED) {
if (x86_pmu.intel_cap.pebs_format < 5)
@ -1391,9 +1401,7 @@ void intel_pmu_pebs_disable(struct perf_event *event)
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
if (cpuc->n_pebs == cpuc->n_large_pebs &&
cpuc->n_pebs != cpuc->n_pebs_via_pt)
intel_pmu_drain_pebs_buffer();
intel_pmu_drain_large_pebs(cpuc);
cpuc->pebs_enabled &= ~(1ULL << hwc->idx);

View File

@ -121,6 +121,9 @@
#define PEBS_DATACFG_LBRS BIT_ULL(3)
#define PEBS_DATACFG_LBR_SHIFT 24
/* Steal the highest bit of pebs_data_cfg for SW usage */
#define PEBS_UPDATE_DS_SW BIT_ULL(63)
/*
* Intel "Architectural Performance Monitoring" CPUID
* detection/enumeration details:

View File

@ -10150,8 +10150,20 @@ void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
perf_trace_buf_update(record, event_type);
hlist_for_each_entry_rcu(event, head, hlist_entry) {
if (perf_tp_event_match(event, &data, regs))
if (perf_tp_event_match(event, &data, regs)) {
perf_swevent_event(event, count, &data, regs);
/*
* Here use the same on-stack perf_sample_data,
* some members in data are event-specific and
* need to be re-computed for different sweveents.
* Re-initialize data->sample_flags safely to avoid
* the problem that next event skips preparing data
* because data->sample_flags is set.
*/
perf_sample_data_init(&data, 0, 0);
perf_sample_save_raw_data(&data, &raw);
}
}
/*