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Diffstat (limited to 'arch/x86/kernel/cpu/perf_event_intel_ds.c')
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_ds.c360
1 files changed, 262 insertions, 98 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 073983398364..71fc40238843 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -11,7 +11,7 @@
#define BTS_RECORD_SIZE 24
#define BTS_BUFFER_SIZE (PAGE_SIZE << 4)
-#define PEBS_BUFFER_SIZE PAGE_SIZE
+#define PEBS_BUFFER_SIZE (PAGE_SIZE << 4)
#define PEBS_FIXUP_SIZE PAGE_SIZE
/*
@@ -250,7 +250,7 @@ static int alloc_pebs_buffer(int cpu)
{
struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
int node = cpu_to_node(cpu);
- int max, thresh = 1; /* always use a single PEBS record */
+ int max;
void *buffer, *ibuffer;
if (!x86_pmu.pebs)
@@ -280,9 +280,6 @@ static int alloc_pebs_buffer(int cpu)
ds->pebs_absolute_maximum = ds->pebs_buffer_base +
max * x86_pmu.pebs_record_size;
- ds->pebs_interrupt_threshold = ds->pebs_buffer_base +
- thresh * x86_pmu.pebs_record_size;
-
return 0;
}
@@ -461,7 +458,8 @@ void intel_pmu_enable_bts(u64 config)
debugctlmsr |= DEBUGCTLMSR_TR;
debugctlmsr |= DEBUGCTLMSR_BTS;
- debugctlmsr |= DEBUGCTLMSR_BTINT;
+ if (config & ARCH_PERFMON_EVENTSEL_INT)
+ debugctlmsr |= DEBUGCTLMSR_BTINT;
if (!(config & ARCH_PERFMON_EVENTSEL_OS))
debugctlmsr |= DEBUGCTLMSR_BTS_OFF_OS;
@@ -548,6 +546,19 @@ int intel_pmu_drain_bts_buffer(void)
return 1;
}
+static inline void intel_pmu_drain_pebs_buffer(void)
+{
+ struct pt_regs regs;
+
+ x86_pmu.drain_pebs(&regs);
+}
+
+void intel_pmu_pebs_sched_task(struct perf_event_context *ctx, bool sched_in)
+{
+ if (!sched_in)
+ intel_pmu_drain_pebs_buffer();
+}
+
/*
* PEBS
*/
@@ -557,6 +568,8 @@ struct event_constraint intel_core2_pebs_event_constraints[] = {
INTEL_FLAGS_UEVENT_CONSTRAINT(0x00c5, 0x1), /* BR_INST_RETIRED.MISPRED */
INTEL_FLAGS_UEVENT_CONSTRAINT(0x1fc7, 0x1), /* SIMD_INST_RETURED.ANY */
INTEL_FLAGS_EVENT_CONSTRAINT(0xcb, 0x1), /* MEM_LOAD_RETIRED.* */
+ /* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
+ INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x01),
EVENT_CONSTRAINT_END
};
@@ -564,6 +577,8 @@ struct event_constraint intel_atom_pebs_event_constraints[] = {
INTEL_FLAGS_UEVENT_CONSTRAINT(0x00c0, 0x1), /* INST_RETIRED.ANY */
INTEL_FLAGS_UEVENT_CONSTRAINT(0x00c5, 0x1), /* MISPREDICTED_BRANCH_RETIRED */
INTEL_FLAGS_EVENT_CONSTRAINT(0xcb, 0x1), /* MEM_LOAD_RETIRED.* */
+ /* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
+ INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x01),
EVENT_CONSTRAINT_END
};
@@ -587,6 +602,8 @@ struct event_constraint intel_nehalem_pebs_event_constraints[] = {
INTEL_FLAGS_UEVENT_CONSTRAINT(0x20c8, 0xf), /* ITLB_MISS_RETIRED */
INTEL_FLAGS_EVENT_CONSTRAINT(0xcb, 0xf), /* MEM_LOAD_RETIRED.* */
INTEL_FLAGS_EVENT_CONSTRAINT(0xf7, 0xf), /* FP_ASSIST.* */
+ /* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
+ INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x0f),
EVENT_CONSTRAINT_END
};
@@ -602,6 +619,8 @@ struct event_constraint intel_westmere_pebs_event_constraints[] = {
INTEL_FLAGS_UEVENT_CONSTRAINT(0x20c8, 0xf), /* ITLB_MISS_RETIRED */
INTEL_FLAGS_EVENT_CONSTRAINT(0xcb, 0xf), /* MEM_LOAD_RETIRED.* */
INTEL_FLAGS_EVENT_CONSTRAINT(0xf7, 0xf), /* FP_ASSIST.* */
+ /* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
+ INTEL_FLAGS_EVENT_CONSTRAINT(0x108000c0, 0x0f),
EVENT_CONSTRAINT_END
};
@@ -611,6 +630,10 @@ struct event_constraint intel_snb_pebs_event_constraints[] = {
INTEL_PST_CONSTRAINT(0x02cd, 0x8), /* MEM_TRANS_RETIRED.PRECISE_STORES */
/* UOPS_RETIRED.ALL, inv=1, cmask=16 (cycles:p). */
INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c2, 0xf),
+ INTEL_EXCLEVT_CONSTRAINT(0xd0, 0xf), /* MEM_UOP_RETIRED.* */
+ INTEL_EXCLEVT_CONSTRAINT(0xd1, 0xf), /* MEM_LOAD_UOPS_RETIRED.* */
+ INTEL_EXCLEVT_CONSTRAINT(0xd2, 0xf), /* MEM_LOAD_UOPS_LLC_HIT_RETIRED.* */
+ INTEL_EXCLEVT_CONSTRAINT(0xd3, 0xf), /* MEM_LOAD_UOPS_LLC_MISS_RETIRED.* */
/* Allow all events as PEBS with no flags */
INTEL_ALL_EVENT_CONSTRAINT(0, 0xf),
EVENT_CONSTRAINT_END
@@ -622,6 +645,10 @@ struct event_constraint intel_ivb_pebs_event_constraints[] = {
INTEL_PST_CONSTRAINT(0x02cd, 0x8), /* MEM_TRANS_RETIRED.PRECISE_STORES */
/* UOPS_RETIRED.ALL, inv=1, cmask=16 (cycles:p). */
INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c2, 0xf),
+ INTEL_EXCLEVT_CONSTRAINT(0xd0, 0xf), /* MEM_UOP_RETIRED.* */
+ INTEL_EXCLEVT_CONSTRAINT(0xd1, 0xf), /* MEM_LOAD_UOPS_RETIRED.* */
+ INTEL_EXCLEVT_CONSTRAINT(0xd2, 0xf), /* MEM_LOAD_UOPS_LLC_HIT_RETIRED.* */
+ INTEL_EXCLEVT_CONSTRAINT(0xd3, 0xf), /* MEM_LOAD_UOPS_LLC_MISS_RETIRED.* */
/* Allow all events as PEBS with no flags */
INTEL_ALL_EVENT_CONSTRAINT(0, 0xf),
EVENT_CONSTRAINT_END
@@ -633,16 +660,16 @@ struct event_constraint intel_hsw_pebs_event_constraints[] = {
/* UOPS_RETIRED.ALL, inv=1, cmask=16 (cycles:p). */
INTEL_FLAGS_EVENT_CONSTRAINT(0x108001c2, 0xf),
INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA(0x01c2, 0xf), /* UOPS_RETIRED.ALL */
- INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x11d0, 0xf), /* MEM_UOPS_RETIRED.STLB_MISS_LOADS */
- INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x21d0, 0xf), /* MEM_UOPS_RETIRED.LOCK_LOADS */
- INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x41d0, 0xf), /* MEM_UOPS_RETIRED.SPLIT_LOADS */
- INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_LD(0x81d0, 0xf), /* MEM_UOPS_RETIRED.ALL_LOADS */
- INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x12d0, 0xf), /* MEM_UOPS_RETIRED.STLB_MISS_STORES */
- INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x42d0, 0xf), /* MEM_UOPS_RETIRED.SPLIT_STORES */
- INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_ST(0x82d0, 0xf), /* MEM_UOPS_RETIRED.ALL_STORES */
- INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD(0xd1, 0xf), /* MEM_LOAD_UOPS_RETIRED.* */
- INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD(0xd2, 0xf), /* MEM_LOAD_UOPS_L3_HIT_RETIRED.* */
- INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_LD(0xd3, 0xf), /* MEM_LOAD_UOPS_L3_MISS_RETIRED.* */
+ INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XLD(0x11d0, 0xf), /* MEM_UOPS_RETIRED.STLB_MISS_LOADS */
+ INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XLD(0x21d0, 0xf), /* MEM_UOPS_RETIRED.LOCK_LOADS */
+ INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XLD(0x41d0, 0xf), /* MEM_UOPS_RETIRED.SPLIT_LOADS */
+ INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XLD(0x81d0, 0xf), /* MEM_UOPS_RETIRED.ALL_LOADS */
+ INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XST(0x12d0, 0xf), /* MEM_UOPS_RETIRED.STLB_MISS_STORES */
+ INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XST(0x42d0, 0xf), /* MEM_UOPS_RETIRED.SPLIT_STORES */
+ INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_XST(0x82d0, 0xf), /* MEM_UOPS_RETIRED.ALL_STORES */
+ INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_XLD(0xd1, 0xf), /* MEM_LOAD_UOPS_RETIRED.* */
+ INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_XLD(0xd2, 0xf), /* MEM_LOAD_UOPS_L3_HIT_RETIRED.* */
+ INTEL_FLAGS_EVENT_CONSTRAINT_DATALA_XLD(0xd3, 0xf), /* MEM_LOAD_UOPS_L3_MISS_RETIRED.* */
/* Allow all events as PEBS with no flags */
INTEL_ALL_EVENT_CONSTRAINT(0, 0xf),
EVENT_CONSTRAINT_END
@@ -667,33 +694,81 @@ struct event_constraint *intel_pebs_constraints(struct perf_event *event)
return &emptyconstraint;
}
+static inline bool pebs_is_enabled(struct cpu_hw_events *cpuc)
+{
+ return (cpuc->pebs_enabled & ((1ULL << MAX_PEBS_EVENTS) - 1));
+}
+
void intel_pmu_pebs_enable(struct perf_event *event)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
+ struct debug_store *ds = cpuc->ds;
+ bool first_pebs;
+ u64 threshold;
hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
+ first_pebs = !pebs_is_enabled(cpuc);
cpuc->pebs_enabled |= 1ULL << hwc->idx;
if (event->hw.flags & PERF_X86_EVENT_PEBS_LDLAT)
cpuc->pebs_enabled |= 1ULL << (hwc->idx + 32);
else if (event->hw.flags & PERF_X86_EVENT_PEBS_ST)
cpuc->pebs_enabled |= 1ULL << 63;
+
+ /*
+ * When the event is constrained enough we can use a larger
+ * threshold and run the event with less frequent PMI.
+ */
+ if (hwc->flags & PERF_X86_EVENT_FREERUNNING) {
+ threshold = ds->pebs_absolute_maximum -
+ x86_pmu.max_pebs_events * x86_pmu.pebs_record_size;
+
+ if (first_pebs)
+ perf_sched_cb_inc(event->ctx->pmu);
+ } else {
+ threshold = ds->pebs_buffer_base + x86_pmu.pebs_record_size;
+
+ /*
+ * If not all events can use larger buffer,
+ * roll back to threshold = 1
+ */
+ if (!first_pebs &&
+ (ds->pebs_interrupt_threshold > threshold))
+ perf_sched_cb_dec(event->ctx->pmu);
+ }
+
+ /* Use auto-reload if possible to save a MSR write in the PMI */
+ if (hwc->flags & PERF_X86_EVENT_AUTO_RELOAD) {
+ ds->pebs_event_reset[hwc->idx] =
+ (u64)(-hwc->sample_period) & x86_pmu.cntval_mask;
+ }
+
+ if (first_pebs || ds->pebs_interrupt_threshold > threshold)
+ ds->pebs_interrupt_threshold = threshold;
}
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;
+ struct debug_store *ds = cpuc->ds;
cpuc->pebs_enabled &= ~(1ULL << hwc->idx);
- if (event->hw.constraint->flags & PERF_X86_EVENT_PEBS_LDLAT)
+ if (event->hw.flags & PERF_X86_EVENT_PEBS_LDLAT)
cpuc->pebs_enabled &= ~(1ULL << (hwc->idx + 32));
- else if (event->hw.constraint->flags & PERF_X86_EVENT_PEBS_ST)
+ else if (event->hw.flags & PERF_X86_EVENT_PEBS_ST)
cpuc->pebs_enabled &= ~(1ULL << 63);
+ if (ds->pebs_interrupt_threshold >
+ ds->pebs_buffer_base + x86_pmu.pebs_record_size) {
+ intel_pmu_drain_pebs_buffer();
+ if (!pebs_is_enabled(cpuc))
+ perf_sched_cb_dec(event->ctx->pmu);
+ }
+
if (cpuc->enabled)
wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
@@ -829,8 +904,10 @@ static inline u64 intel_hsw_transaction(struct pebs_record_hsw *pebs)
return txn;
}
-static void __intel_pmu_pebs_event(struct perf_event *event,
- struct pt_regs *iregs, void *__pebs)
+static void setup_pebs_sample_data(struct perf_event *event,
+ struct pt_regs *iregs, void *__pebs,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
{
#define PERF_X86_EVENT_PEBS_HSW_PREC \
(PERF_X86_EVENT_PEBS_ST_HSW | \
@@ -842,13 +919,11 @@ static void __intel_pmu_pebs_event(struct perf_event *event,
*/
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct pebs_record_hsw *pebs = __pebs;
- struct perf_sample_data data;
- struct pt_regs regs;
u64 sample_type;
int fll, fst, dsrc;
int fl = event->hw.flags;
- if (!intel_pmu_save_and_restart(event))
+ if (pebs == NULL)
return;
sample_type = event->attr.sample_type;
@@ -857,15 +932,15 @@ static void __intel_pmu_pebs_event(struct perf_event *event,
fll = fl & PERF_X86_EVENT_PEBS_LDLAT;
fst = fl & (PERF_X86_EVENT_PEBS_ST | PERF_X86_EVENT_PEBS_HSW_PREC);
- perf_sample_data_init(&data, 0, event->hw.last_period);
+ perf_sample_data_init(data, 0, event->hw.last_period);
- data.period = event->hw.last_period;
+ data->period = event->hw.last_period;
/*
* Use latency for weight (only avail with PEBS-LL)
*/
if (fll && (sample_type & PERF_SAMPLE_WEIGHT))
- data.weight = pebs->lat;
+ data->weight = pebs->lat;
/*
* data.data_src encodes the data source
@@ -878,7 +953,7 @@ static void __intel_pmu_pebs_event(struct perf_event *event,
val = precise_datala_hsw(event, pebs->dse);
else if (fst)
val = precise_store_data(pebs->dse);
- data.data_src.val = val;
+ data->data_src.val = val;
}
/*
@@ -891,61 +966,123 @@ static void __intel_pmu_pebs_event(struct perf_event *event,
* PERF_SAMPLE_IP and PERF_SAMPLE_CALLCHAIN to function properly.
* A possible PERF_SAMPLE_REGS will have to transfer all regs.
*/
- regs = *iregs;
- regs.flags = pebs->flags;
- set_linear_ip(&regs, pebs->ip);
- regs.bp = pebs->bp;
- regs.sp = pebs->sp;
+ *regs = *iregs;
+ regs->flags = pebs->flags;
+ set_linear_ip(regs, pebs->ip);
+ regs->bp = pebs->bp;
+ regs->sp = pebs->sp;
if (sample_type & PERF_SAMPLE_REGS_INTR) {
- regs.ax = pebs->ax;
- regs.bx = pebs->bx;
- regs.cx = pebs->cx;
- regs.dx = pebs->dx;
- regs.si = pebs->si;
- regs.di = pebs->di;
- regs.bp = pebs->bp;
- regs.sp = pebs->sp;
-
- regs.flags = pebs->flags;
+ regs->ax = pebs->ax;
+ regs->bx = pebs->bx;
+ regs->cx = pebs->cx;
+ regs->dx = pebs->dx;
+ regs->si = pebs->si;
+ regs->di = pebs->di;
+ regs->bp = pebs->bp;
+ regs->sp = pebs->sp;
+
+ regs->flags = pebs->flags;
#ifndef CONFIG_X86_32
- regs.r8 = pebs->r8;
- regs.r9 = pebs->r9;
- regs.r10 = pebs->r10;
- regs.r11 = pebs->r11;
- regs.r12 = pebs->r12;
- regs.r13 = pebs->r13;
- regs.r14 = pebs->r14;
- regs.r15 = pebs->r15;
+ regs->r8 = pebs->r8;
+ regs->r9 = pebs->r9;
+ regs->r10 = pebs->r10;
+ regs->r11 = pebs->r11;
+ regs->r12 = pebs->r12;
+ regs->r13 = pebs->r13;
+ regs->r14 = pebs->r14;
+ regs->r15 = pebs->r15;
#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;
+ 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;
+ regs->flags &= ~PERF_EFLAGS_EXACT;
if ((sample_type & PERF_SAMPLE_ADDR) &&
x86_pmu.intel_cap.pebs_format >= 1)
- data.addr = pebs->dla;
+ data->addr = pebs->dla;
if (x86_pmu.intel_cap.pebs_format >= 2) {
/* Only set the TSX weight when no memory weight. */
if ((sample_type & PERF_SAMPLE_WEIGHT) && !fll)
- data.weight = intel_hsw_weight(pebs);
+ data->weight = intel_hsw_weight(pebs);
if (sample_type & PERF_SAMPLE_TRANSACTION)
- data.txn = intel_hsw_transaction(pebs);
+ data->txn = intel_hsw_transaction(pebs);
}
if (has_branch_stack(event))
- data.br_stack = &cpuc->lbr_stack;
+ data->br_stack = &cpuc->lbr_stack;
+}
+
+static inline void *
+get_next_pebs_record_by_bit(void *base, void *top, int bit)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ void *at;
+ u64 pebs_status;
+
+ if (base == NULL)
+ return NULL;
- if (perf_event_overflow(event, &data, &regs))
+ for (at = base; at < top; at += x86_pmu.pebs_record_size) {
+ struct pebs_record_nhm *p = at;
+
+ if (test_bit(bit, (unsigned long *)&p->status)) {
+ /* PEBS v3 has accurate status bits */
+ if (x86_pmu.intel_cap.pebs_format >= 3)
+ return at;
+
+ if (p->status == (1 << bit))
+ return at;
+
+ /* clear non-PEBS bit and re-check */
+ pebs_status = p->status & cpuc->pebs_enabled;
+ pebs_status &= (1ULL << MAX_PEBS_EVENTS) - 1;
+ if (pebs_status == (1 << bit))
+ return at;
+ }
+ }
+ return NULL;
+}
+
+static void __intel_pmu_pebs_event(struct perf_event *event,
+ struct pt_regs *iregs,
+ void *base, void *top,
+ int bit, int count)
+{
+ 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))
+ return;
+
+ while (count > 1) {
+ setup_pebs_sample_data(event, iregs, at, &data, &regs);
+ perf_event_output(event, &data, &regs);
+ at += x86_pmu.pebs_record_size;
+ at = get_next_pebs_record_by_bit(at, top, bit);
+ count--;
+ }
+
+ setup_pebs_sample_data(event, iregs, at, &data, &regs);
+
+ /*
+ * All but the last records are processed.
+ * The last one is left to be able to call the overflow handler.
+ */
+ if (perf_event_overflow(event, &data, &regs)) {
x86_pmu_stop(event, 0);
+ return;
+ }
+
}
static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
@@ -975,72 +1112,99 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
if (!event->attr.precise_ip)
return;
- n = top - at;
+ n = (top - at) / x86_pmu.pebs_record_size;
if (n <= 0)
return;
- /*
- * Should not happen, we program the threshold at 1 and do not
- * set a reset value.
- */
- WARN_ONCE(n > 1, "bad leftover pebs %d\n", n);
- at += n - 1;
-
- __intel_pmu_pebs_event(event, iregs, at);
+ __intel_pmu_pebs_event(event, iregs, at, top, 0, n);
}
static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct debug_store *ds = cpuc->ds;
- struct perf_event *event = NULL;
- void *at, *top;
- u64 status = 0;
- int bit;
+ struct perf_event *event;
+ void *base, *at, *top;
+ short counts[MAX_PEBS_EVENTS] = {};
+ short error[MAX_PEBS_EVENTS] = {};
+ int bit, i;
if (!x86_pmu.pebs_active)
return;
- at = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;
+ base = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;
top = (struct pebs_record_nhm *)(unsigned long)ds->pebs_index;
ds->pebs_index = ds->pebs_buffer_base;
- if (unlikely(at > top))
+ if (unlikely(base >= top))
return;
- /*
- * Should not happen, we program the threshold at 1 and do not
- * set a reset value.
- */
- WARN_ONCE(top - at > x86_pmu.max_pebs_events * x86_pmu.pebs_record_size,
- "Unexpected number of pebs records %ld\n",
- (long)(top - at) / x86_pmu.pebs_record_size);
-
- for (; at < top; at += x86_pmu.pebs_record_size) {
+ for (at = base; at < top; at += x86_pmu.pebs_record_size) {
struct pebs_record_nhm *p = at;
- for_each_set_bit(bit, (unsigned long *)&p->status,
- x86_pmu.max_pebs_events) {
- event = cpuc->events[bit];
- if (!test_bit(bit, cpuc->active_mask))
- continue;
-
- WARN_ON_ONCE(!event);
+ /* PEBS v3 has accurate status bits */
+ if (x86_pmu.intel_cap.pebs_format >= 3) {
+ for_each_set_bit(bit, (unsigned long *)&p->status,
+ MAX_PEBS_EVENTS)
+ counts[bit]++;
- if (!event->attr.precise_ip)
- continue;
+ continue;
+ }
- if (__test_and_set_bit(bit, (unsigned long *)&status))
+ bit = find_first_bit((unsigned long *)&p->status,
+ x86_pmu.max_pebs_events);
+ if (bit >= x86_pmu.max_pebs_events)
+ continue;
+ if (!test_bit(bit, cpuc->active_mask))
+ continue;
+ /*
+ * The PEBS hardware does not deal well with the situation
+ * when events happen near to each other and multiple bits
+ * are set. But it should happen rarely.
+ *
+ * If these events include one PEBS and multiple non-PEBS
+ * events, it doesn't impact PEBS record. The record will
+ * be handled normally. (slow path)
+ *
+ * If these events include two or more PEBS events, the
+ * records for the events can be collapsed into a single
+ * one, and it's not possible to reconstruct all events
+ * that caused the PEBS record. It's called collision.
+ * If collision happened, the record will be dropped.
+ *
+ */
+ if (p->status != (1 << bit)) {
+ u64 pebs_status;
+
+ /* slow path */
+ pebs_status = p->status & cpuc->pebs_enabled;
+ pebs_status &= (1ULL << MAX_PEBS_EVENTS) - 1;
+ if (pebs_status != (1 << bit)) {
+ for_each_set_bit(i, (unsigned long *)&pebs_status,
+ MAX_PEBS_EVENTS)
+ error[i]++;
continue;
-
- break;
+ }
}
+ counts[bit]++;
+ }
- if (!event || bit >= x86_pmu.max_pebs_events)
+ for (bit = 0; bit < x86_pmu.max_pebs_events; bit++) {
+ if ((counts[bit] == 0) && (error[bit] == 0))
continue;
+ event = cpuc->events[bit];
+ WARN_ON_ONCE(!event);
+ WARN_ON_ONCE(!event->attr.precise_ip);
- __intel_pmu_pebs_event(event, iregs, at);
+ /* log dropped samples number */
+ if (error[bit])
+ perf_log_lost_samples(event, error[bit]);
+
+ if (counts[bit]) {
+ __intel_pmu_pebs_event(event, iregs, base,
+ top, bit, counts[bit]);
+ }
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-02 16:07:47 +0000