Stitch LBR call stack (Perf Tools)

From: Kan Liang <[email protected]>

The low level index of raw branch records for the most recent branch can be recorded in a sample with PERF_SAMPLE_BRANCH_HW_INDEX branch_sample_type. Extend struct branch_stack to support it.

However, if the PERF_SAMPLE_BRANCH_HW_INDEX is not applied, only nr and entries[] will be output by kernel. The pointer of entries[] could be wrong, since the output format is different with new struct branch_stack. Add a variable no_hw_idx in struct perf_sample to indicate whether the hw_idx is output.
Add get_branch_entry() to return corresponding pointer of entries[0].

To make dummy branch sample consistent as new branch sample, add hw_idx in struct dummy_branch_stack for cs-etm and intel-pt.

Apply the new struct branch_stack for synthetic events as well.

Extend test case sample-parsing to support new struct branch_stack.

Signed-off-by Kan Liang <[email protected]>

---
 tools/include/uapi/linux/perf_event.h         |  8 ++-
 tools/perf/builtin-script.c                   | 70 ++++++++++---------
 tools/perf/tests/sample-parsing.c             |  7 +-
 tools/perf/util/branch.h                      | 22 ++++++
 tools/perf/util/cs-etm.c                      |  1 +
 tools/perf/util/event.h                       |  1 +
 tools/perf/util/evsel.c                       |  5 ++
 tools/perf/util/evsel.h                       |  5 ++
 tools/perf/util/hist.c                        |  3 +-
 tools/perf/util/intel-pt.c                    |  2 +
 tools/perf/util/machine.c                     | 35 +++++-----
 .../scripting-engines/trace-event-python.c    | 30 ++++----
 tools/perf/util/session.c                     |  8 ++-
 tools/perf/util/synthetic-events.c            |  6 +-
 14 files changed, 131 insertions(+), 72 deletions(-)

tools/include/uapi/linux/perf_event.h +7 -1

index 377d794d3105..397cfd65b3fe 100644
@@ -181,6 +181,8 @@ enum perf_branch_sample_type_shift {
 
 	PERF_SAMPLE_BRANCH_TYPE_SAVE_SHIFT	= 16, /* save branch type */
 
+	PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT	= 17, /* save low level index of raw branch records */
+
 	PERF_SAMPLE_BRANCH_MAX_SHIFT		/* non-ABI */
 };
 

@@ -208,6 +210,8 @@ enum perf_branch_sample_type {
 	PERF_SAMPLE_BRANCH_TYPE_SAVE	=
 		1U << PERF_SAMPLE_BRANCH_TYPE_SAVE_SHIFT,
 
+	PERF_SAMPLE_BRANCH_HW_INDEX	= 1U << PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT,
+
 	PERF_SAMPLE_BRANCH_MAX		= 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT,
 };
 

@@ -853,7 +857,9 @@ enum perf_event_type {
 	 *	  char                  data[size];}&& PERF_SAMPLE_RAW
 	 *
 	 *	{ u64                   nr;
-	 *        { u64 from, to, flags } lbr[nr];} && PERF_SAMPLE_BRANCH_STACK
+	 *	  { u64	hw_idx; } && PERF_SAMPLE_BRANCH_HW_INDEX
+	 *        { u64 from, to, flags } lbr[nr];
+	 *      } && PERF_SAMPLE_BRANCH_STACK
 	 *
 	 * 	{ u64			abi; # enum perf_sample_regs_abi
 	 * 	  u64			regs[weight(mask)]; } && PERF_SAMPLE_REGS_USER

tools/perf/builtin-script.c +37 -33

index e2406b291c1c..acf3107bbda2 100644
@@ -735,6 +735,7 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
 					struct perf_event_attr *attr, FILE *fp)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct addr_location alf, alt;
 	u64 i, from, to;
 	int printed = 0;

@@ -743,8 +744,8 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
 		return 0;
 
 	for (i = 0; i < br->nr; i++) {
-		from = br->entries[i].from;
-		to   = br->entries[i].to;
+		from = entries[i].from;
+		to   = entries[i].to;
 
 		if (PRINT_FIELD(DSO)) {
 			memset(&alf, 0, sizeof(alf));

@@ -768,10 +769,10 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
 		}
 
 		printed += fprintf(fp, "/%c/%c/%c/%d ",
-			mispred_str( br->entries + i),
-			br->entries[i].flags.in_tx? 'X' : '-',
-			br->entries[i].flags.abort? 'A' : '-',
-			br->entries[i].flags.cycles);
+			mispred_str(entries + i),
+			entries[i].flags.in_tx ? 'X' : '-',
+			entries[i].flags.abort ? 'A' : '-',
+			entries[i].flags.cycles);
 	}
 
 	return printed;

@@ -782,6 +783,7 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
 					   struct perf_event_attr *attr, FILE *fp)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct addr_location alf, alt;
 	u64 i, from, to;
 	int printed = 0;

@@ -793,8 +795,8 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
 
 		memset(&alf, 0, sizeof(alf));
 		memset(&alt, 0, sizeof(alt));
-		from = br->entries[i].from;
-		to   = br->entries[i].to;
+		from = entries[i].from;
+		to   = entries[i].to;
 
 		thread__find_symbol_fb(thread, sample->cpumode, from, &alf);
 		thread__find_symbol_fb(thread, sample->cpumode, to, &alt);

@@ -813,10 +815,10 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
 			printed += fprintf(fp, ")");
 		}
 		printed += fprintf(fp, "/%c/%c/%c/%d ",
-			mispred_str( br->entries + i),
-			br->entries[i].flags.in_tx? 'X' : '-',
-			br->entries[i].flags.abort? 'A' : '-',
-			br->entries[i].flags.cycles);
+			mispred_str(entries + i),
+			entries[i].flags.in_tx ? 'X' : '-',
+			entries[i].flags.abort ? 'A' : '-',
+			entries[i].flags.cycles);
 	}
 
 	return printed;

@@ -827,6 +829,7 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
 					   struct perf_event_attr *attr, FILE *fp)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct addr_location alf, alt;
 	u64 i, from, to;
 	int printed = 0;

@@ -838,8 +841,8 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
 
 		memset(&alf, 0, sizeof(alf));
 		memset(&alt, 0, sizeof(alt));
-		from = br->entries[i].from;
-		to   = br->entries[i].to;
+		from = entries[i].from;
+		to   = entries[i].to;
 
 		if (thread__find_map_fb(thread, sample->cpumode, from, &alf) &&
 		    !alf.map->dso->adjust_symbols)

@@ -862,10 +865,10 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
 			printed += fprintf(fp, ")");
 		}
 		printed += fprintf(fp, "/%c/%c/%c/%d ",
-			mispred_str(br->entries + i),
-			br->entries[i].flags.in_tx ? 'X' : '-',
-			br->entries[i].flags.abort ? 'A' : '-',
-			br->entries[i].flags.cycles);
+			mispred_str(entries + i),
+			entries[i].flags.in_tx ? 'X' : '-',
+			entries[i].flags.abort ? 'A' : '-',
+			entries[i].flags.cycles);
 	}
 
 	return printed;

@@ -1053,6 +1056,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 					    struct machine *machine, FILE *fp)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	u64 start, end;
 	int i, insn, len, nr, ilen, printed = 0;
 	struct perf_insn x;

@@ -1073,31 +1077,31 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 	printed += fprintf(fp, "%c", '\n');
 
 	/* Handle first from jump, of which we don't know the entry. */
-	len = grab_bb(buffer, br->entries[nr-1].from,
-			br->entries[nr-1].from,
+	len = grab_bb(buffer, entries[nr-1].from,
+			entries[nr-1].from,
 			machine, thread, &x.is64bit, &x.cpumode, false);
 	if (len > 0) {
-		printed += ip__fprintf_sym(br->entries[nr - 1].from, thread,
+		printed += ip__fprintf_sym(entries[nr - 1].from, thread,
 					   x.cpumode, x.cpu, &lastsym, attr, fp);
-		printed += ip__fprintf_jump(br->entries[nr - 1].from, &br->entries[nr - 1],
+		printed += ip__fprintf_jump(entries[nr - 1].from, &entries[nr - 1],
 					    &x, buffer, len, 0, fp, &total_cycles);
 		if (PRINT_FIELD(SRCCODE))
-			printed += print_srccode(thread, x.cpumode, br->entries[nr - 1].from);
+			printed += print_srccode(thread, x.cpumode, entries[nr - 1].from);
 	}
 
 	/* Print all blocks */
 	for (i = nr - 2; i >= 0; i--) {
-		if (br->entries[i].from || br->entries[i].to)
+		if (entries[i].from || entries[i].to)
 			pr_debug("%d: %" PRIx64 "-%" PRIx64 "\n", i,
-				 br->entries[i].from,
-				 br->entries[i].to);
-		start = br->entries[i + 1].to;
-		end   = br->entries[i].from;
+				 entries[i].from,
+				 entries[i].to);
+		start = entries[i + 1].to;
+		end   = entries[i].from;
 
 		len = grab_bb(buffer, start, end, machine, thread, &x.is64bit, &x.cpumode, false);
 		/* Patch up missing kernel transfers due to ring filters */
 		if (len == -ENXIO && i > 0) {
-			end = br->entries[--i].from;
+			end = entries[--i].from;
 			pr_debug("\tpatching up to %" PRIx64 "-%" PRIx64 "\n", start, end);
 			len = grab_bb(buffer, start, end, machine, thread, &x.is64bit, &x.cpumode, false);
 		}

@@ -1110,7 +1114,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 
 			printed += ip__fprintf_sym(ip, thread, x.cpumode, x.cpu, &lastsym, attr, fp);
 			if (ip == end) {
-				printed += ip__fprintf_jump(ip, &br->entries[i], &x, buffer + off, len - off, ++insn, fp,
+				printed += ip__fprintf_jump(ip, &entries[i], &x, buffer + off, len - off, ++insn, fp,
 							    &total_cycles);
 				if (PRINT_FIELD(SRCCODE))
 					printed += print_srccode(thread, x.cpumode, ip);

@@ -1134,9 +1138,9 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 	 * Hit the branch? In this case we are already done, and the target
 	 * has not been executed yet.
 	 */
-	if (br->entries[0].from == sample->ip)
+	if (entries[0].from == sample->ip)
 		goto out;
-	if (br->entries[0].flags.abort)
+	if (entries[0].flags.abort)
 		goto out;
 
 	/*

@@ -1147,7 +1151,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 	 * between final branch and sample. When this happens just
 	 * continue walking after the last TO until we hit a branch.
 	 */
-	start = br->entries[0].to;
+	start = entries[0].to;
 	end = sample->ip;
 	if (end < start) {
 		/* Missing jump. Scan 128 bytes for the next branch */

tools/perf/tests/sample-parsing.c +6 -1

index 2762e1155238..14239e472187 100644
@@ -99,6 +99,7 @@ static bool samples_same(const struct perf_sample *s1,
 
 	if (type & PERF_SAMPLE_BRANCH_STACK) {
 		COMP(branch_stack->nr);
+		COMP(branch_stack->hw_idx);
 		for (i = 0; i < s1->branch_stack->nr; i++)
 			MCOMP(branch_stack->entries[i]);
 	}

@@ -186,7 +187,7 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
 		u64 data[64];
 	} branch_stack = {
 		/* 1 branch_entry */
-		.data = {1, 211, 212, 213},
+		.data = {1, -1ULL, 211, 212, 213},
 	};
 	u64 regs[64];
 	const u64 raw_data[] = {0x123456780a0b0c0dULL, 0x1102030405060708ULL};

@@ -208,6 +209,7 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
 		.transaction	= 112,
 		.raw_data	= (void *)raw_data,
 		.callchain	= &callchain.callchain,
+		.no_hw_idx      = false,
 		.branch_stack	= &branch_stack.branch_stack,
 		.user_regs	= {
 			.abi	= PERF_SAMPLE_REGS_ABI_64,

@@ -244,6 +246,9 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
 	if (sample_type & PERF_SAMPLE_REGS_INTR)
 		evsel.core.attr.sample_regs_intr = sample_regs;
 
+	if (sample_type & PERF_SAMPLE_BRANCH_STACK)
+		evsel.core.attr.branch_sample_type |= PERF_SAMPLE_BRANCH_HW_INDEX;
+
 	for (i = 0; i < sizeof(regs); i++)
 		*(i + (u8 *)regs) = i & 0xfe;
 

tools/perf/util/branch.h +22 -0

index 88e00d268f6f..7fc9fa0dc361 100644
@@ -12,6 +12,7 @@
 #include <linux/stddef.h>
 #include <linux/perf_event.h>
 #include <linux/types.h>
+#include "event.h"
 
 struct branch_flags {
 	u64 mispred:1;

@@ -39,9 +40,30 @@ struct branch_entry {
 
 struct branch_stack {
 	u64			nr;
+	u64			hw_idx;
 	struct branch_entry	entries[0];
 };
 
+/*
+ * The hw_idx is only available when PERF_SAMPLE_BRANCH_HW_INDEX is applied.
+ * Otherwise, the output format of a sample with branch stack is
+ * struct branch_stack {
+ *	u64			nr;
+ *	struct branch_entry	entries[0];
+ * }
+ * Check whether the hw_idx is available,
+ * and return the corresponding pointer of entries[0].
+ */
+inline struct branch_entry *get_branch_entry(struct perf_sample *sample)
+{
+	u64 *entry = (u64 *)sample->branch_stack;
+
+	entry++;
+	if (sample->no_hw_idx)
+		return (struct branch_entry *)entry;
+	return (struct branch_entry *)(++entry);
+}
+
 struct branch_type_stat {
 	bool	branch_to;
 	u64	counts[PERF_BR_MAX];

tools/perf/util/cs-etm.c +1 -0

index 5471045ebf5c..e697fe1c67b3 100644
@@ -1202,6 +1202,7 @@ static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq,
 	if (etm->synth_opts.last_branch) {
 		dummy_bs = (struct dummy_branch_stack){
 			.nr = 1,
+			.hw_idx = -1ULL,
 			.entries = {
 				.from = sample.ip,
 				.to = sample.addr,

tools/perf/util/event.h +1 -0

index 85223159737c..3cda40a2fafc 100644
@@ -139,6 +139,7 @@ struct perf_sample {
 	u16 insn_len;
 	u8  cpumode;
 	u16 misc;
+	bool no_hw_idx;		/* No hw_idx collected in branch_stack */
 	char insn[MAX_INSN];
 	void *raw_data;
 	struct ip_callchain *callchain;

tools/perf/util/evsel.c +5 -0

index c8dc4450884c..05883a45de5b 100644
@@ -2169,7 +2169,12 @@ int perf_evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 
 		if (data->branch_stack->nr > max_branch_nr)
 			return -EFAULT;
+
 		sz = data->branch_stack->nr * sizeof(struct branch_entry);
+		if (perf_evsel__has_branch_hw_idx(evsel))
+			sz += sizeof(u64);
+		else
+			data->no_hw_idx = true;
 		OVERFLOW_CHECK(array, sz, max_size);
 		array = (void *)array + sz;
 	}

tools/perf/util/evsel.h +5 -0

index dc14f4a823cd..99a0cb60c556 100644
@@ -389,6 +389,11 @@ static inline bool perf_evsel__has_branch_callstack(const struct evsel *evsel)
 	return evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK;
 }
 
+static inline bool perf_evsel__has_branch_hw_idx(const struct evsel *evsel)
+{
+	return evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX;
+}
+
 static inline bool evsel__has_callchain(const struct evsel *evsel)
 {
 	return (evsel->core.attr.sample_type & PERF_SAMPLE_CALLCHAIN) != 0;

tools/perf/util/hist.c +2 -1

index ca5a8f4d007e..808ca27bd5cf 100644
@@ -2584,9 +2584,10 @@ void hist__account_cycles(struct branch_stack *bs, struct addr_location *al,
 			  u64 *total_cycles)
 {
 	struct branch_info *bi;
+	struct branch_entry *entries = get_branch_entry(sample);
 
 	/* If we have branch cycles always annotate them. */
-	if (bs && bs->nr && bs->entries[0].flags.cycles) {
+	if (bs && bs->nr && entries[0].flags.cycles) {
 		int i;
 
 		bi = sample__resolve_bstack(sample, al);

tools/perf/util/intel-pt.c +2 -0

index 33cf8928cf05..23c8289c2472 100644
@@ -1295,6 +1295,7 @@ static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq)
 	struct perf_sample sample = { .ip = 0, };
 	struct dummy_branch_stack {
 		u64			nr;
+		u64			hw_idx;
 		struct branch_entry	entries;
 	} dummy_bs;
 

@@ -1316,6 +1317,7 @@ static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq)
 	if (pt->synth_opts.last_branch && sort__mode == SORT_MODE__BRANCH) {
 		dummy_bs = (struct dummy_branch_stack){
 			.nr = 1,
+			.hw_idx = -1ULL,
 			.entries = {
 				.from = sample.ip,
 				.to = sample.addr,

tools/perf/util/machine.c +18 -17

index c8c5410315e8..62522b76a924 100644
@@ -2083,15 +2083,16 @@ struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
 {
 	unsigned int i;
 	const struct branch_stack *bs = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));
 
 	if (!bi)
 		return NULL;
 
 	for (i = 0; i < bs->nr; i++) {
-		ip__resolve_ams(al->thread, &bi[i].to, bs->entries[i].to);
-		ip__resolve_ams(al->thread, &bi[i].from, bs->entries[i].from);
-		bi[i].flags = bs->entries[i].flags;
+		ip__resolve_ams(al->thread, &bi[i].to, entries[i].to);
+		ip__resolve_ams(al->thread, &bi[i].from, entries[i].from);
+		bi[i].flags = entries[i].flags;
 	}
 	return bi;
 }

@@ -2187,6 +2188,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
 	/* LBR only affects the user callchain */
 	if (i != chain_nr) {
 		struct branch_stack *lbr_stack = sample->branch_stack;
+		struct branch_entry *entries = get_branch_entry(sample);
 		int lbr_nr = lbr_stack->nr, j, k;
 		bool branch;
 		struct branch_flags *flags;

@@ -2212,31 +2214,29 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
 					ip = chain->ips[j];
 				else if (j > i + 1) {
 					k = j - i - 2;
-					ip = lbr_stack->entries[k].from;
+					ip = entries[k].from;
 					branch = true;
-					flags = &lbr_stack->entries[k].flags;
+					flags = &entries[k].flags;
 				} else {
-					ip = lbr_stack->entries[0].to;
+					ip = entries[0].to;
 					branch = true;
-					flags = &lbr_stack->entries[0].flags;
-					branch_from =
-						lbr_stack->entries[0].from;
+					flags = &entries[0].flags;
+					branch_from = entries[0].from;
 				}
 			} else {
 				if (j < lbr_nr) {
 					k = lbr_nr - j - 1;
-					ip = lbr_stack->entries[k].from;
+					ip = entries[k].from;
 					branch = true;
-					flags = &lbr_stack->entries[k].flags;
+					flags = &entries[k].flags;
 				}
 				else if (j > lbr_nr)
 					ip = chain->ips[i + 1 - (j - lbr_nr)];
 				else {
-					ip = lbr_stack->entries[0].to;
+					ip = entries[0].to;
 					branch = true;
-					flags = &lbr_stack->entries[0].flags;
-					branch_from =
-						lbr_stack->entries[0].from;
+					flags = &entries[0].flags;
+					branch_from = entries[0].from;
 				}
 			}
 

@@ -2283,6 +2283,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
 					    int max_stack)
 {
 	struct branch_stack *branch = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct ip_callchain *chain = sample->callchain;
 	int chain_nr = 0;
 	u8 cpumode = PERF_RECORD_MISC_USER;

@@ -2330,7 +2331,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
 
 		for (i = 0; i < nr; i++) {
 			if (callchain_param.order == ORDER_CALLEE) {
-				be[i] = branch->entries[i];
+				be[i] = entries[i];
 
 				if (chain == NULL)
 					continue;

@@ -2349,7 +2350,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
 				    be[i].from >= chain->ips[first_call] - 8)
 					first_call++;
 			} else
-				be[i] = branch->entries[branch->nr - i - 1];
+				be[i] = entries[branch->nr - i - 1];
 		}
 
 		memset(iter, 0, sizeof(struct iterations) * nr);

tools/perf/util/scripting-engines/trace-event-python.c +16 -14

index 80ca5d0ab7fe..02b6c87c5abe 100644
@@ -464,6 +464,7 @@ static PyObject *python_process_brstack(struct perf_sample *sample,
 					struct thread *thread)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	PyObject *pylist;
 	u64 i;
 

@@ -484,28 +485,28 @@ static PyObject *python_process_brstack(struct perf_sample *sample,
 			Py_FatalError("couldn't create Python dictionary");
 
 		pydict_set_item_string_decref(pyelem, "from",
-		    PyLong_FromUnsignedLongLong(br->entries[i].from));
+		    PyLong_FromUnsignedLongLong(entries[i].from));
 		pydict_set_item_string_decref(pyelem, "to",
-		    PyLong_FromUnsignedLongLong(br->entries[i].to));
+		    PyLong_FromUnsignedLongLong(entries[i].to));
 		pydict_set_item_string_decref(pyelem, "mispred",
-		    PyBool_FromLong(br->entries[i].flags.mispred));
+		    PyBool_FromLong(entries[i].flags.mispred));
 		pydict_set_item_string_decref(pyelem, "predicted",
-		    PyBool_FromLong(br->entries[i].flags.predicted));
+		    PyBool_FromLong(entries[i].flags.predicted));
 		pydict_set_item_string_decref(pyelem, "in_tx",
-		    PyBool_FromLong(br->entries[i].flags.in_tx));
+		    PyBool_FromLong(entries[i].flags.in_tx));
 		pydict_set_item_string_decref(pyelem, "abort",
-		    PyBool_FromLong(br->entries[i].flags.abort));
+		    PyBool_FromLong(entries[i].flags.abort));
 		pydict_set_item_string_decref(pyelem, "cycles",
-		    PyLong_FromUnsignedLongLong(br->entries[i].flags.cycles));
+		    PyLong_FromUnsignedLongLong(entries[i].flags.cycles));
 
 		thread__find_map_fb(thread, sample->cpumode,
-				    br->entries[i].from, &al);
+				    entries[i].from, &al);
 		dsoname = get_dsoname(al.map);
 		pydict_set_item_string_decref(pyelem, "from_dsoname",
 					      _PyUnicode_FromString(dsoname));
 
 		thread__find_map_fb(thread, sample->cpumode,
-				    br->entries[i].to, &al);
+				    entries[i].to, &al);
 		dsoname = get_dsoname(al.map);
 		pydict_set_item_string_decref(pyelem, "to_dsoname",
 					      _PyUnicode_FromString(dsoname));

@@ -561,6 +562,7 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
 					   struct thread *thread)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	PyObject *pylist;
 	u64 i;
 	char bf[512];

@@ -581,22 +583,22 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
 			Py_FatalError("couldn't create Python dictionary");
 
 		thread__find_symbol_fb(thread, sample->cpumode,
-				       br->entries[i].from, &al);
+				       entries[i].from, &al);
 		get_symoff(al.sym, &al, true, bf, sizeof(bf));
 		pydict_set_item_string_decref(pyelem, "from",
 					      _PyUnicode_FromString(bf));
 
 		thread__find_symbol_fb(thread, sample->cpumode,
-				       br->entries[i].to, &al);
+				       entries[i].to, &al);
 		get_symoff(al.sym, &al, true, bf, sizeof(bf));
 		pydict_set_item_string_decref(pyelem, "to",
 					      _PyUnicode_FromString(bf));
 
-		get_br_mspred(&br->entries[i].flags, bf, sizeof(bf));
+		get_br_mspred(&entries[i].flags, bf, sizeof(bf));
 		pydict_set_item_string_decref(pyelem, "pred",
 					      _PyUnicode_FromString(bf));
 
-		if (br->entries[i].flags.in_tx) {
+		if (entries[i].flags.in_tx) {
 			pydict_set_item_string_decref(pyelem, "in_tx",
 					      _PyUnicode_FromString("X"));
 		} else {

@@ -604,7 +606,7 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
 					      _PyUnicode_FromString("-"));
 		}
 
-		if (br->entries[i].flags.abort) {
+		if (entries[i].flags.abort) {
 			pydict_set_item_string_decref(pyelem, "abort",
 					      _PyUnicode_FromString("A"));
 		} else {

tools/perf/util/session.c +5 -3

index d0d7d25b23e3..dab985e3f136 100644
@@ -1007,6 +1007,7 @@ static void callchain__lbr_callstack_printf(struct perf_sample *sample)
 {
 	struct ip_callchain *callchain = sample->callchain;
 	struct branch_stack *lbr_stack = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	u64 kernel_callchain_nr = callchain->nr;
 	unsigned int i;
 

@@ -1043,10 +1044,10 @@ static void callchain__lbr_callstack_printf(struct perf_sample *sample)
 			       i, callchain->ips[i]);
 
 		printf("..... %2d: %016" PRIx64 "\n",
-		       (int)(kernel_callchain_nr), lbr_stack->entries[0].to);
+		       (int)(kernel_callchain_nr), entries[0].to);
 		for (i = 0; i < lbr_stack->nr; i++)
 			printf("..... %2d: %016" PRIx64 "\n",
-			       (int)(i + kernel_callchain_nr + 1), lbr_stack->entries[i].from);
+			       (int)(i + kernel_callchain_nr + 1), entries[i].from);
 	}
 }
 

@@ -1068,6 +1069,7 @@ static void callchain__printf(struct evsel *evsel,
 
 static void branch_stack__printf(struct perf_sample *sample, bool callstack)
 {
+	struct branch_entry *entries = get_branch_entry(sample);
 	uint64_t i;
 
 	printf("%s: nr:%" PRIu64 "\n",

@@ -1075,7 +1077,7 @@ static void branch_stack__printf(struct perf_sample *sample, bool callstack)
 		sample->branch_stack->nr);
 
 	for (i = 0; i < sample->branch_stack->nr; i++) {
-		struct branch_entry *e = &sample->branch_stack->entries[i];
+		struct branch_entry *e = &entries[i];
 
 		if (!callstack) {
 			printf("..... %2"PRIu64": %016" PRIx64 " -> %016" PRIx64 " %hu cycles %s%s%s%s %x\n",

tools/perf/util/synthetic-events.c +4 -2

index c423298fe62d..dd3e6f43fb86 100644
@@ -1183,7 +1183,8 @@ size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type,
 
 	if (type & PERF_SAMPLE_BRANCH_STACK) {
 		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
-		sz += sizeof(u64);
+		/* nr, hw_idx */
+		sz += 2 * sizeof(u64);
 		result += sz;
 	}
 

@@ -1344,7 +1345,8 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_fo
 
 	if (type & PERF_SAMPLE_BRANCH_STACK) {
 		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
-		sz += sizeof(u64);
+		/* nr, hw_idx */
+		sz += 2 * sizeof(u64);
 		memcpy(array, sample->branch_stack, sz);
 		array = (void *)array + sz;
 	}

Signature · 1 line

2.17.1

Em Fri, Feb 28, 2020 at 08:30:00AM -0800, [email protected] escreveu:

Quoted 11 lines

From: Kan Liang <[email protected]>
The low level index of raw branch records for the most recent branch can be recorded in a sample with PERF_SAMPLE_BRANCH_HW_INDEX branch_sample_type. Extend struct branch_stack to support it.

However, if the PERF_SAMPLE_BRANCH_HW_INDEX is not applied, only nr and entries[] will be output by kernel. The pointer of entries[] could be wrong, since the output format is different with new struct branch_stack. Add a variable no_hw_idx in struct perf_sample to indicate whether the hw_idx is output.
Add get_branch_entry() to return corresponding pointer of entries[0].

This should be broken up in at least two patches, one that syncs tools/include/uapi/linux/perf_event.h with the kernel, and another to do what this changeset log message states, I'll do it this time to expedite processing of this patchset, please do it that way next time.

Em Wed, Mar 04, 2020 at 10:49:02AM -0300, Arnaldo Carvalho de Melo escreveu:

Quoted 17 lines

Em Fri, Feb 28, 2020 at 08:30:00AM -0800, [email protected] escreveu:

Quoted 11 lines

From: Kan Liang <[email protected]>
The low level index of raw branch records for the most recent branch can be recorded in a sample with PERF_SAMPLE_BRANCH_HW_INDEX branch_sample_type. Extend struct branch_stack to support it.

However, if the PERF_SAMPLE_BRANCH_HW_INDEX is not applied, only nr and entries[] will be output by kernel. The pointer of entries[] could be wrong, since the output format is different with new struct branch_stack. Add a variable no_hw_idx in struct perf_sample to indicate whether the hw_idx is output.
Add get_branch_entry() to return corresponding pointer of entries[0].

This should be broken up in at least two patches, one that syncs tools/include/uapi/linux/perf_event.h with the kernel, and another to do what this changeset log message states, I'll do it this time to expedite processing of this patchset, please do it that way next time.

So, after doing that split I'm also suggesting/tentatively applying this patch on top of it, to keep the naming convention we have in tools/perf, and also the 'static' to that inline,

please holler if you disagree,
I'll put the end result in a branch for further visualization/comments.

At some point these functions obtaining stuff from a 'struct perf_sample' to tools/lib/perf/ (aka libperf), so better go doing proper namespacing, etc, right Jiri?

- Arnaldo

tools/perf/builtin-script.c +4 -4

index acf3107bbda2..656b347f6dd8 100644
@@ -735,7 +735,7 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
  					struct perf_event_attr *attr, FILE *fp)
  {
  	struct branch_stack *br = sample->branch_stack;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	struct addr_location alf, alt;
  	u64 i, from, to;
  	int printed = 0;

@@ -783,7 +783,7 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
  					   struct perf_event_attr *attr, FILE *fp)
  {
  	struct branch_stack *br = sample->branch_stack;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	struct addr_location alf, alt;
  	u64 i, from, to;
  	int printed = 0;

@@ -829,7 +829,7 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
  					   struct perf_event_attr *attr, FILE *fp)
  {
  	struct branch_stack *br = sample->branch_stack;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	struct addr_location alf, alt;
  	u64 i, from, to;
  	int printed = 0;

@@ -1056,7 +1056,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
  					    struct machine *machine, FILE *fp)
  {
  	struct branch_stack *br = sample->branch_stack;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	u64 start, end;
  	int i, insn, len, nr, ilen, printed = 0;
  	struct perf_insn x;

tools/perf/util/branch.h +1 -1

index 014c3cd4cb32..154a05cd03af 100644
@@ -54,7 +54,7 @@ struct branch_stack {
   * Check whether the hw_idx is available,
   * and return the corresponding pointer of entries[0].
   */
-inline struct branch_entry *get_branch_entry(struct perf_sample *sample)
+static inline struct branch_entry *perf_sample__branch_entries(struct perf_sample *sample)
  {
  	u64 *entry = (u64 *)sample->branch_stack;
 

tools/perf/util/hist.c +1 -1

index 808ca27bd5cf..e74a5acf66d9 100644
@@ -2584,7 +2584,7 @@ void hist__account_cycles(struct branch_stack *bs, struct addr_location *al,
  			  u64 *total_cycles)
  {
  	struct branch_info *bi;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
 
  	/* If we have branch cycles always annotate them. */
  	if (bs && bs->nr && entries[0].flags.cycles) {

tools/perf/util/machine.c +3 -3

index b0623f99fb9c..fd14f1489802 100644
@@ -2081,7 +2081,7 @@ struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
  {
  	unsigned int i;
  	const struct branch_stack *bs = sample->branch_stack;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));
 
  	if (!bi)

@@ -2186,7 +2186,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
  	/* LBR only affects the user callchain */
  	if (i != chain_nr) {
  		struct branch_stack *lbr_stack = sample->branch_stack;
-		struct branch_entry *entries = get_branch_entry(sample);
+		struct branch_entry *entries = perf_sample__branch_entries(sample);
  		int lbr_nr = lbr_stack->nr, j, k;
  		bool branch;
  		struct branch_flags *flags;

@@ -2281,7 +2281,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
  					    int max_stack)
  {
  	struct branch_stack *branch = sample->branch_stack;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	struct ip_callchain *chain = sample->callchain;
  	int chain_nr = 0;
  	u8 cpumode = PERF_RECORD_MISC_USER;

tools/perf/util/scripting-engines/trace-event-python.c +2 -2

index 02b6c87c5abe..8c1b27cd8b99 100644
@@ -464,7 +464,7 @@ static PyObject *python_process_brstack(struct perf_sample *sample,
  					struct thread *thread)
  {
  	struct branch_stack *br = sample->branch_stack;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	PyObject *pylist;
  	u64 i;
 

@@ -562,7 +562,7 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
  					   struct thread *thread)
  {
  	struct branch_stack *br = sample->branch_stack;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	PyObject *pylist;
  	u64 i;
  	char bf[512];

tools/perf/util/session.c +2 -2

index dab985e3f136..055b00abd56d 100644
@@ -1007,7 +1007,7 @@ static void callchain__lbr_callstack_printf(struct perf_sample *sample)
  {
  	struct ip_callchain *callchain = sample->callchain;
  	struct branch_stack *lbr_stack = sample->branch_stack;
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	u64 kernel_callchain_nr = callchain->nr;
  	unsigned int i;
 

@@ -1069,7 +1069,7 @@ static void callchain__printf(struct evsel *evsel,
 
  static void branch_stack__printf(struct perf_sample *sample, bool callstack)
  {
-	struct branch_entry *entries = get_branch_entry(sample);
+	struct branch_entry *entries = perf_sample__branch_entries(sample);
  	uint64_t i;
 
  	printf("%s: nr:%" PRIu64 "\n",

From: Kan Liang <[email protected]>

The low level index of raw branch records for the most recent branch can be recorded in a sample with PERF_SAMPLE_BRANCH_HW_INDEX branch_sample_type. Extend struct branch_stack to support it.

However, if the PERF_SAMPLE_BRANCH_HW_INDEX is not applied, only nr and entries[] will be output by kernel. The pointer of entries[] could be wrong, since the output format is different with new struct branch_stack. Add a variable no_hw_idx in struct perf_sample to indicate whether the hw_idx is output.
Add get_branch_entry() to return corresponding pointer of entries[0].

To make dummy branch sample consistent as new branch sample, add hw_idx in struct dummy_branch_stack for cs-etm and intel-pt.

Apply the new struct branch_stack for synthetic events as well.

Extend test case sample-parsing to support new struct branch_stack.

Signed-off-by Kan Liang <[email protected]>

---
 tools/include/uapi/linux/perf_event.h         |  8 ++-
 tools/perf/builtin-script.c                   | 70 ++++++++++---------
 tools/perf/tests/sample-parsing.c             |  7 +-
 tools/perf/util/branch.h                      | 22 ++++++
 tools/perf/util/cs-etm.c                      |  1 +
 tools/perf/util/event.h                       |  1 +
 tools/perf/util/evsel.c                       |  5 ++
 tools/perf/util/evsel.h                       |  5 ++
 tools/perf/util/hist.c                        |  3 +-
 tools/perf/util/intel-pt.c                    |  2 +
 tools/perf/util/machine.c                     | 35 +++++-----
 .../scripting-engines/trace-event-python.c    | 30 ++++----
 tools/perf/util/session.c                     |  8 ++-
 tools/perf/util/synthetic-events.c            |  6 +-
 14 files changed, 131 insertions(+), 72 deletions(-)

tools/include/uapi/linux/perf_event.h +7 -1

index 377d794d3105..397cfd65b3fe 100644
@@ -181,6 +181,8 @@ enum perf_branch_sample_type_shift {
 
 	PERF_SAMPLE_BRANCH_TYPE_SAVE_SHIFT	= 16, /* save branch type */
 
+	PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT	= 17, /* save low level index of raw branch records */
+
 	PERF_SAMPLE_BRANCH_MAX_SHIFT		/* non-ABI */
 };
 

@@ -208,6 +210,8 @@ enum perf_branch_sample_type {
 	PERF_SAMPLE_BRANCH_TYPE_SAVE	=
 		1U << PERF_SAMPLE_BRANCH_TYPE_SAVE_SHIFT,
 
+	PERF_SAMPLE_BRANCH_HW_INDEX	= 1U << PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT,
+
 	PERF_SAMPLE_BRANCH_MAX		= 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT,
 };
 

@@ -853,7 +857,9 @@ enum perf_event_type {
 	 *	  char                  data[size];}&& PERF_SAMPLE_RAW
 	 *
 	 *	{ u64                   nr;
-	 *        { u64 from, to, flags } lbr[nr];} && PERF_SAMPLE_BRANCH_STACK
+	 *	  { u64	hw_idx; } && PERF_SAMPLE_BRANCH_HW_INDEX
+	 *        { u64 from, to, flags } lbr[nr];
+	 *      } && PERF_SAMPLE_BRANCH_STACK
 	 *
 	 * 	{ u64			abi; # enum perf_sample_regs_abi
 	 * 	  u64			regs[weight(mask)]; } && PERF_SAMPLE_REGS_USER

tools/perf/builtin-script.c +37 -33

index e2406b291c1c..acf3107bbda2 100644
@@ -735,6 +735,7 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
 					struct perf_event_attr *attr, FILE *fp)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct addr_location alf, alt;
 	u64 i, from, to;
 	int printed = 0;

@@ -743,8 +744,8 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
 		return 0;
 
 	for (i = 0; i < br->nr; i++) {
-		from = br->entries[i].from;
-		to   = br->entries[i].to;
+		from = entries[i].from;
+		to   = entries[i].to;
 
 		if (PRINT_FIELD(DSO)) {
 			memset(&alf, 0, sizeof(alf));

@@ -768,10 +769,10 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
 		}
 
 		printed += fprintf(fp, "/%c/%c/%c/%d ",
-			mispred_str( br->entries + i),
-			br->entries[i].flags.in_tx? 'X' : '-',
-			br->entries[i].flags.abort? 'A' : '-',
-			br->entries[i].flags.cycles);
+			mispred_str(entries + i),
+			entries[i].flags.in_tx ? 'X' : '-',
+			entries[i].flags.abort ? 'A' : '-',
+			entries[i].flags.cycles);
 	}
 
 	return printed;

@@ -782,6 +783,7 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
 					   struct perf_event_attr *attr, FILE *fp)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct addr_location alf, alt;
 	u64 i, from, to;
 	int printed = 0;

@@ -793,8 +795,8 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
 
 		memset(&alf, 0, sizeof(alf));
 		memset(&alt, 0, sizeof(alt));
-		from = br->entries[i].from;
-		to   = br->entries[i].to;
+		from = entries[i].from;
+		to   = entries[i].to;
 
 		thread__find_symbol_fb(thread, sample->cpumode, from, &alf);
 		thread__find_symbol_fb(thread, sample->cpumode, to, &alt);

@@ -813,10 +815,10 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
 			printed += fprintf(fp, ")");
 		}
 		printed += fprintf(fp, "/%c/%c/%c/%d ",
-			mispred_str( br->entries + i),
-			br->entries[i].flags.in_tx? 'X' : '-',
-			br->entries[i].flags.abort? 'A' : '-',
-			br->entries[i].flags.cycles);
+			mispred_str(entries + i),
+			entries[i].flags.in_tx ? 'X' : '-',
+			entries[i].flags.abort ? 'A' : '-',
+			entries[i].flags.cycles);
 	}
 
 	return printed;

@@ -827,6 +829,7 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
 					   struct perf_event_attr *attr, FILE *fp)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct addr_location alf, alt;
 	u64 i, from, to;
 	int printed = 0;

@@ -838,8 +841,8 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
 
 		memset(&alf, 0, sizeof(alf));
 		memset(&alt, 0, sizeof(alt));
-		from = br->entries[i].from;
-		to   = br->entries[i].to;
+		from = entries[i].from;
+		to   = entries[i].to;
 
 		if (thread__find_map_fb(thread, sample->cpumode, from, &alf) &&
 		    !alf.map->dso->adjust_symbols)

@@ -862,10 +865,10 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
 			printed += fprintf(fp, ")");
 		}
 		printed += fprintf(fp, "/%c/%c/%c/%d ",
-			mispred_str(br->entries + i),
-			br->entries[i].flags.in_tx ? 'X' : '-',
-			br->entries[i].flags.abort ? 'A' : '-',
-			br->entries[i].flags.cycles);
+			mispred_str(entries + i),
+			entries[i].flags.in_tx ? 'X' : '-',
+			entries[i].flags.abort ? 'A' : '-',
+			entries[i].flags.cycles);
 	}
 
 	return printed;

@@ -1053,6 +1056,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 					    struct machine *machine, FILE *fp)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	u64 start, end;
 	int i, insn, len, nr, ilen, printed = 0;
 	struct perf_insn x;

@@ -1073,31 +1077,31 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 	printed += fprintf(fp, "%c", '\n');
 
 	/* Handle first from jump, of which we don't know the entry. */
-	len = grab_bb(buffer, br->entries[nr-1].from,
-			br->entries[nr-1].from,
+	len = grab_bb(buffer, entries[nr-1].from,
+			entries[nr-1].from,
 			machine, thread, &x.is64bit, &x.cpumode, false);
 	if (len > 0) {
-		printed += ip__fprintf_sym(br->entries[nr - 1].from, thread,
+		printed += ip__fprintf_sym(entries[nr - 1].from, thread,
 					   x.cpumode, x.cpu, &lastsym, attr, fp);
-		printed += ip__fprintf_jump(br->entries[nr - 1].from, &br->entries[nr - 1],
+		printed += ip__fprintf_jump(entries[nr - 1].from, &entries[nr - 1],
 					    &x, buffer, len, 0, fp, &total_cycles);
 		if (PRINT_FIELD(SRCCODE))
-			printed += print_srccode(thread, x.cpumode, br->entries[nr - 1].from);
+			printed += print_srccode(thread, x.cpumode, entries[nr - 1].from);
 	}
 
 	/* Print all blocks */
 	for (i = nr - 2; i >= 0; i--) {
-		if (br->entries[i].from || br->entries[i].to)
+		if (entries[i].from || entries[i].to)
 			pr_debug("%d: %" PRIx64 "-%" PRIx64 "\n", i,
-				 br->entries[i].from,
-				 br->entries[i].to);
-		start = br->entries[i + 1].to;
-		end   = br->entries[i].from;
+				 entries[i].from,
+				 entries[i].to);
+		start = entries[i + 1].to;
+		end   = entries[i].from;
 
 		len = grab_bb(buffer, start, end, machine, thread, &x.is64bit, &x.cpumode, false);
 		/* Patch up missing kernel transfers due to ring filters */
 		if (len == -ENXIO && i > 0) {
-			end = br->entries[--i].from;
+			end = entries[--i].from;
 			pr_debug("\tpatching up to %" PRIx64 "-%" PRIx64 "\n", start, end);
 			len = grab_bb(buffer, start, end, machine, thread, &x.is64bit, &x.cpumode, false);
 		}

@@ -1110,7 +1114,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 
 			printed += ip__fprintf_sym(ip, thread, x.cpumode, x.cpu, &lastsym, attr, fp);
 			if (ip == end) {
-				printed += ip__fprintf_jump(ip, &br->entries[i], &x, buffer + off, len - off, ++insn, fp,
+				printed += ip__fprintf_jump(ip, &entries[i], &x, buffer + off, len - off, ++insn, fp,
 							    &total_cycles);
 				if (PRINT_FIELD(SRCCODE))
 					printed += print_srccode(thread, x.cpumode, ip);

@@ -1134,9 +1138,9 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 	 * Hit the branch? In this case we are already done, and the target
 	 * has not been executed yet.
 	 */
-	if (br->entries[0].from == sample->ip)
+	if (entries[0].from == sample->ip)
 		goto out;
-	if (br->entries[0].flags.abort)
+	if (entries[0].flags.abort)
 		goto out;
 
 	/*

@@ -1147,7 +1151,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 	 * between final branch and sample. When this happens just
 	 * continue walking after the last TO until we hit a branch.
 	 */
-	start = br->entries[0].to;
+	start = entries[0].to;
 	end = sample->ip;
 	if (end < start) {
 		/* Missing jump. Scan 128 bytes for the next branch */

tools/perf/tests/sample-parsing.c +6 -1

index 2762e1155238..14239e472187 100644
@@ -99,6 +99,7 @@ static bool samples_same(const struct perf_sample *s1,
 
 	if (type & PERF_SAMPLE_BRANCH_STACK) {
 		COMP(branch_stack->nr);
+		COMP(branch_stack->hw_idx);
 		for (i = 0; i < s1->branch_stack->nr; i++)
 			MCOMP(branch_stack->entries[i]);
 	}

@@ -186,7 +187,7 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
 		u64 data[64];
 	} branch_stack = {
 		/* 1 branch_entry */
-		.data = {1, 211, 212, 213},
+		.data = {1, -1ULL, 211, 212, 213},
 	};
 	u64 regs[64];
 	const u64 raw_data[] = {0x123456780a0b0c0dULL, 0x1102030405060708ULL};

@@ -208,6 +209,7 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
 		.transaction	= 112,
 		.raw_data	= (void *)raw_data,
 		.callchain	= &callchain.callchain,
+		.no_hw_idx      = false,
 		.branch_stack	= &branch_stack.branch_stack,
 		.user_regs	= {
 			.abi	= PERF_SAMPLE_REGS_ABI_64,

@@ -244,6 +246,9 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
 	if (sample_type & PERF_SAMPLE_REGS_INTR)
 		evsel.core.attr.sample_regs_intr = sample_regs;
 
+	if (sample_type & PERF_SAMPLE_BRANCH_STACK)
+		evsel.core.attr.branch_sample_type |= PERF_SAMPLE_BRANCH_HW_INDEX;
+
 	for (i = 0; i < sizeof(regs); i++)
 		*(i + (u8 *)regs) = i & 0xfe;
 

tools/perf/util/branch.h +22 -0

index 88e00d268f6f..7fc9fa0dc361 100644
@@ -12,6 +12,7 @@
 #include <linux/stddef.h>
 #include <linux/perf_event.h>
 #include <linux/types.h>
+#include "event.h"
 
 struct branch_flags {
 	u64 mispred:1;

@@ -39,9 +40,30 @@ struct branch_entry {
 
 struct branch_stack {
 	u64			nr;
+	u64			hw_idx;
 	struct branch_entry	entries[0];
 };
 
+/*
+ * The hw_idx is only available when PERF_SAMPLE_BRANCH_HW_INDEX is applied.
+ * Otherwise, the output format of a sample with branch stack is
+ * struct branch_stack {
+ *	u64			nr;
+ *	struct branch_entry	entries[0];
+ * }
+ * Check whether the hw_idx is available,
+ * and return the corresponding pointer of entries[0].
+ */
+inline struct branch_entry *get_branch_entry(struct perf_sample *sample)
+{
+	u64 *entry = (u64 *)sample->branch_stack;
+
+	entry++;
+	if (sample->no_hw_idx)
+		return (struct branch_entry *)entry;
+	return (struct branch_entry *)(++entry);
+}
+
 struct branch_type_stat {
 	bool	branch_to;
 	u64	counts[PERF_BR_MAX];

tools/perf/util/cs-etm.c +0 -0

index 5471045ebf5c..e697fe1c67b3 100644

tools/perf/util/event.h +1 -0

index 85223159737c..3cda40a2fafc 100644
@@ -139,6 +139,7 @@ struct perf_sample {
 	u16 insn_len;
 	u8  cpumode;
 	u16 misc;
+	bool no_hw_idx;		/* No hw_idx collected in branch_stack */
 	char insn[MAX_INSN];
 	void *raw_data;
 	struct ip_callchain *callchain;

tools/perf/util/evsel.c +5 -0

index c8dc4450884c..05883a45de5b 100644
@@ -2169,7 +2169,12 @@ int perf_evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 
 		if (data->branch_stack->nr > max_branch_nr)
 			return -EFAULT;
+
 		sz = data->branch_stack->nr * sizeof(struct branch_entry);
+		if (perf_evsel__has_branch_hw_idx(evsel))
+			sz += sizeof(u64);
+		else
+			data->no_hw_idx = true;
 		OVERFLOW_CHECK(array, sz, max_size);
 		array = (void *)array + sz;
 	}

tools/perf/util/evsel.h +5 -0

index dc14f4a823cd..99a0cb60c556 100644
@@ -389,6 +389,11 @@ static inline bool perf_evsel__has_branch_callstack(const struct evsel *evsel)
 	return evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK;
 }
 
+static inline bool perf_evsel__has_branch_hw_idx(const struct evsel *evsel)
+{
+	return evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX;
+}
+
 static inline bool evsel__has_callchain(const struct evsel *evsel)
 {
 	return (evsel->core.attr.sample_type & PERF_SAMPLE_CALLCHAIN) != 0;

tools/perf/util/hist.c +2 -1

index ca5a8f4d007e..808ca27bd5cf 100644
@@ -2584,9 +2584,10 @@ void hist__account_cycles(struct branch_stack *bs, struct addr_location *al,
 			  u64 *total_cycles)
 {
 	struct branch_info *bi;
+	struct branch_entry *entries = get_branch_entry(sample);
 
 	/* If we have branch cycles always annotate them. */
-	if (bs && bs->nr && bs->entries[0].flags.cycles) {
+	if (bs && bs->nr && entries[0].flags.cycles) {
 		int i;
 
 		bi = sample__resolve_bstack(sample, al);

tools/perf/util/intel-pt.c +2 -0

index 33cf8928cf05..23c8289c2472 100644
@@ -1295,6 +1295,7 @@ static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq)
 	struct perf_sample sample = { .ip = 0, };
 	struct dummy_branch_stack {
 		u64			nr;
+		u64			hw_idx;
 		struct branch_entry	entries;
 	} dummy_bs;
 

@@ -1316,6 +1317,7 @@ static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq)
 	if (pt->synth_opts.last_branch && sort__mode == SORT_MODE__BRANCH) {
 		dummy_bs = (struct dummy_branch_stack){
 			.nr = 1,
+			.hw_idx = -1ULL,
 			.entries = {
 				.from = sample.ip,
 				.to = sample.addr,

tools/perf/util/machine.c +18 -17

index c8c5410315e8..62522b76a924 100644
@@ -2083,15 +2083,16 @@ struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
 {
 	unsigned int i;
 	const struct branch_stack *bs = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));
 
 	if (!bi)
 		return NULL;
 
 	for (i = 0; i < bs->nr; i++) {
-		ip__resolve_ams(al->thread, &bi[i].to, bs->entries[i].to);
-		ip__resolve_ams(al->thread, &bi[i].from, bs->entries[i].from);
-		bi[i].flags = bs->entries[i].flags;
+		ip__resolve_ams(al->thread, &bi[i].to, entries[i].to);
+		ip__resolve_ams(al->thread, &bi[i].from, entries[i].from);
+		bi[i].flags = entries[i].flags;
 	}
 	return bi;
 }

@@ -2187,6 +2188,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
 	/* LBR only affects the user callchain */
 	if (i != chain_nr) {
 		struct branch_stack *lbr_stack = sample->branch_stack;
+		struct branch_entry *entries = get_branch_entry(sample);
 		int lbr_nr = lbr_stack->nr, j, k;
 		bool branch;
 		struct branch_flags *flags;

@@ -2212,31 +2214,29 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
 					ip = chain->ips[j];
 				else if (j > i + 1) {
 					k = j - i - 2;
-					ip = lbr_stack->entries[k].from;
+					ip = entries[k].from;
 					branch = true;
-					flags = &lbr_stack->entries[k].flags;
+					flags = &entries[k].flags;
 				} else {
-					ip = lbr_stack->entries[0].to;
+					ip = entries[0].to;
 					branch = true;
-					flags = &lbr_stack->entries[0].flags;
-					branch_from =
-						lbr_stack->entries[0].from;
+					flags = &entries[0].flags;
+					branch_from = entries[0].from;
 				}
 			} else {
 				if (j < lbr_nr) {
 					k = lbr_nr - j - 1;
-					ip = lbr_stack->entries[k].from;
+					ip = entries[k].from;
 					branch = true;
-					flags = &lbr_stack->entries[k].flags;
+					flags = &entries[k].flags;
 				}
 				else if (j > lbr_nr)
 					ip = chain->ips[i + 1 - (j - lbr_nr)];
 				else {
-					ip = lbr_stack->entries[0].to;
+					ip = entries[0].to;
 					branch = true;
-					flags = &lbr_stack->entries[0].flags;
-					branch_from =
-						lbr_stack->entries[0].from;
+					flags = &entries[0].flags;
+					branch_from = entries[0].from;
 				}
 			}
 

@@ -2283,6 +2283,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
 					    int max_stack)
 {
 	struct branch_stack *branch = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	struct ip_callchain *chain = sample->callchain;
 	int chain_nr = 0;
 	u8 cpumode = PERF_RECORD_MISC_USER;

@@ -2330,7 +2331,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
 
 		for (i = 0; i < nr; i++) {
 			if (callchain_param.order == ORDER_CALLEE) {
-				be[i] = branch->entries[i];
+				be[i] = entries[i];
 
 				if (chain == NULL)
 					continue;

@@ -2349,7 +2350,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
 				    be[i].from >= chain->ips[first_call] - 8)
 					first_call++;
 			} else
-				be[i] = branch->entries[branch->nr - i - 1];
+				be[i] = entries[branch->nr - i - 1];
 		}
 
 		memset(iter, 0, sizeof(struct iterations) * nr);

tools/perf/util/scripting-engines/trace-event-python.c +16 -14

index 80ca5d0ab7fe..02b6c87c5abe 100644
@@ -464,6 +464,7 @@ static PyObject *python_process_brstack(struct perf_sample *sample,
 					struct thread *thread)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	PyObject *pylist;
 	u64 i;
 

@@ -484,28 +485,28 @@ static PyObject *python_process_brstack(struct perf_sample *sample,
 			Py_FatalError("couldn't create Python dictionary");
 
 		pydict_set_item_string_decref(pyelem, "from",
-		    PyLong_FromUnsignedLongLong(br->entries[i].from));
+		    PyLong_FromUnsignedLongLong(entries[i].from));
 		pydict_set_item_string_decref(pyelem, "to",
-		    PyLong_FromUnsignedLongLong(br->entries[i].to));
+		    PyLong_FromUnsignedLongLong(entries[i].to));
 		pydict_set_item_string_decref(pyelem, "mispred",
-		    PyBool_FromLong(br->entries[i].flags.mispred));
+		    PyBool_FromLong(entries[i].flags.mispred));
 		pydict_set_item_string_decref(pyelem, "predicted",
-		    PyBool_FromLong(br->entries[i].flags.predicted));
+		    PyBool_FromLong(entries[i].flags.predicted));
 		pydict_set_item_string_decref(pyelem, "in_tx",
-		    PyBool_FromLong(br->entries[i].flags.in_tx));
+		    PyBool_FromLong(entries[i].flags.in_tx));
 		pydict_set_item_string_decref(pyelem, "abort",
-		    PyBool_FromLong(br->entries[i].flags.abort));
+		    PyBool_FromLong(entries[i].flags.abort));
 		pydict_set_item_string_decref(pyelem, "cycles",
-		    PyLong_FromUnsignedLongLong(br->entries[i].flags.cycles));
+		    PyLong_FromUnsignedLongLong(entries[i].flags.cycles));
 
 		thread__find_map_fb(thread, sample->cpumode,
-				    br->entries[i].from, &al);
+				    entries[i].from, &al);
 		dsoname = get_dsoname(al.map);
 		pydict_set_item_string_decref(pyelem, "from_dsoname",
 					      _PyUnicode_FromString(dsoname));
 
 		thread__find_map_fb(thread, sample->cpumode,
-				    br->entries[i].to, &al);
+				    entries[i].to, &al);
 		dsoname = get_dsoname(al.map);
 		pydict_set_item_string_decref(pyelem, "to_dsoname",
 					      _PyUnicode_FromString(dsoname));

@@ -561,6 +562,7 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
 					   struct thread *thread)
 {
 	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	PyObject *pylist;
 	u64 i;
 	char bf[512];

@@ -581,22 +583,22 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
 			Py_FatalError("couldn't create Python dictionary");
 
 		thread__find_symbol_fb(thread, sample->cpumode,
-				       br->entries[i].from, &al);
+				       entries[i].from, &al);
 		get_symoff(al.sym, &al, true, bf, sizeof(bf));
 		pydict_set_item_string_decref(pyelem, "from",
 					      _PyUnicode_FromString(bf));
 
 		thread__find_symbol_fb(thread, sample->cpumode,
-				       br->entries[i].to, &al);
+				       entries[i].to, &al);
 		get_symoff(al.sym, &al, true, bf, sizeof(bf));
 		pydict_set_item_string_decref(pyelem, "to",
 					      _PyUnicode_FromString(bf));
 
-		get_br_mspred(&br->entries[i].flags, bf, sizeof(bf));
+		get_br_mspred(&entries[i].flags, bf, sizeof(bf));
 		pydict_set_item_string_decref(pyelem, "pred",
 					      _PyUnicode_FromString(bf));
 
-		if (br->entries[i].flags.in_tx) {
+		if (entries[i].flags.in_tx) {
 			pydict_set_item_string_decref(pyelem, "in_tx",
 					      _PyUnicode_FromString("X"));
 		} else {

@@ -604,7 +606,7 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
 					      _PyUnicode_FromString("-"));
 		}
 
-		if (br->entries[i].flags.abort) {
+		if (entries[i].flags.abort) {
 			pydict_set_item_string_decref(pyelem, "abort",
 					      _PyUnicode_FromString("A"));
 		} else {

tools/perf/util/session.c +5 -3

index d0d7d25b23e3..dab985e3f136 100644
@@ -1007,6 +1007,7 @@ static void callchain__lbr_callstack_printf(struct perf_sample *sample)
 {
 	struct ip_callchain *callchain = sample->callchain;
 	struct branch_stack *lbr_stack = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
 	u64 kernel_callchain_nr = callchain->nr;
 	unsigned int i;
 

@@ -1043,10 +1044,10 @@ static void callchain__lbr_callstack_printf(struct perf_sample *sample)
 			       i, callchain->ips[i]);
 
 		printf("..... %2d: %016" PRIx64 "\n",
-		       (int)(kernel_callchain_nr), lbr_stack->entries[0].to);
+		       (int)(kernel_callchain_nr), entries[0].to);
 		for (i = 0; i < lbr_stack->nr; i++)
 			printf("..... %2d: %016" PRIx64 "\n",
-			       (int)(i + kernel_callchain_nr + 1), lbr_stack->entries[i].from);
+			       (int)(i + kernel_callchain_nr + 1), entries[i].from);
 	}
 }
 

@@ -1068,6 +1069,7 @@ static void callchain__printf(struct evsel *evsel,
 
 static void branch_stack__printf(struct perf_sample *sample, bool callstack)
 {
+	struct branch_entry *entries = get_branch_entry(sample);
 	uint64_t i;
 
 	printf("%s: nr:%" PRIu64 "\n",

@@ -1075,7 +1077,7 @@ static void branch_stack__printf(struct perf_sample *sample, bool callstack)
 		sample->branch_stack->nr);
 
 	for (i = 0; i < sample->branch_stack->nr; i++) {
-		struct branch_entry *e = &sample->branch_stack->entries[i];
+		struct branch_entry *e = &entries[i];
 
 		if (!callstack) {
 			printf("..... %2"PRIu64": %016" PRIx64 " -> %016" PRIx64 " %hu cycles %s%s%s%s %x\n",

tools/perf/util/synthetic-events.c +4 -2

index c423298fe62d..dd3e6f43fb86 100644
@@ -1183,7 +1183,8 @@ size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type,
 
 	if (type & PERF_SAMPLE_BRANCH_STACK) {
 		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
-		sz += sizeof(u64);
+		/* nr, hw_idx */
+		sz += 2 * sizeof(u64);
 		result += sz;
 	}
 

@@ -1344,7 +1345,8 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_fo
 
 	if (type & PERF_SAMPLE_BRANCH_STACK) {
 		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
-		sz += sizeof(u64);
+		/* nr, hw_idx */
+		sz += 2 * sizeof(u64);
 		memcpy(array, sample->branch_stack, sz);
 		array = (void *)array + sz;
 	}

Signature · 1 line

2.17.1

Em Fri, Feb 28, 2020 at 08:30:00AM -0800, [email protected] escreveu:

Quoted 345 lines

From: Kan Liang <[email protected]>

The low level index of raw branch records for the most recent branch can be recorded in a sample with PERF_SAMPLE_BRANCH_HW_INDEX branch_sample_type. Extend struct branch_stack to support it.

However, if the PERF_SAMPLE_BRANCH_HW_INDEX is not applied, only nr and entries[] will be output by kernel. The pointer of entries[] could be wrong, since the output format is different with new struct branch_stack. Add a variable no_hw_idx in struct perf_sample to indicate whether the hw_idx is output.
Add get_branch_entry() to return corresponding pointer of entries[0].

To make dummy branch sample consistent as new branch sample, add hw_idx in struct dummy_branch_stack for cs-etm and intel-pt.

Apply the new struct branch_stack for synthetic events as well.

Extend test case sample-parsing to support new struct branch_stack.

Signed-off-by Kan Liang <[email protected]>

---
  tools/include/uapi/linux/perf_event.h         |  8 ++-
  tools/perf/builtin-script.c                   | 70 ++++++++++---------
  tools/perf/tests/sample-parsing.c             |  7 +-
  tools/perf/util/branch.h                      | 22 ++++++
  tools/perf/util/cs-etm.c                      |  1 +
  tools/perf/util/event.h                       |  1 +
  tools/perf/util/evsel.c                       |  5 ++
  tools/perf/util/evsel.h                       |  5 ++
  tools/perf/util/hist.c                        |  3 +-
  tools/perf/util/intel-pt.c                    |  2 +
  tools/perf/util/machine.c                     | 35 +++++-----
  .../scripting-engines/trace-event-python.c    | 30 ++++----
  tools/perf/util/session.c                     |  8 ++-
  tools/perf/util/synthetic-events.c            |  6 +-
  14 files changed, 131 insertions(+), 72 deletions(-)

tools/include/uapi/linux/perf_event.h +7 -1

index 377d794d3105..397cfd65b3fe 100644
@@ -181,6 +181,8 @@ enum perf_branch_sample_type_shift {
 
  	PERF_SAMPLE_BRANCH_TYPE_SAVE_SHIFT	= 16, /* save branch type */
 
+	PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT	= 17, /* save low level index of raw branch records */
+
  	PERF_SAMPLE_BRANCH_MAX_SHIFT		/* non-ABI */
  };
 

@@ -208,6 +210,8 @@ enum perf_branch_sample_type {
  	PERF_SAMPLE_BRANCH_TYPE_SAVE	=
  		1U << PERF_SAMPLE_BRANCH_TYPE_SAVE_SHIFT,
 
+	PERF_SAMPLE_BRANCH_HW_INDEX	= 1U << PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT,
+
  	PERF_SAMPLE_BRANCH_MAX		= 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT,
  };
 

@@ -853,7 +857,9 @@ enum perf_event_type {
  	 *	  char                  data[size];}&& PERF_SAMPLE_RAW
  	 *
  	 *	{ u64                   nr;
-	 *        { u64 from, to, flags } lbr[nr];} && PERF_SAMPLE_BRANCH_STACK
+	 *	  { u64	hw_idx; } && PERF_SAMPLE_BRANCH_HW_INDEX
+	 *        { u64 from, to, flags } lbr[nr];
+	 *      } && PERF_SAMPLE_BRANCH_STACK
  	 *
  	 * 	{ u64			abi; # enum perf_sample_regs_abi
  	 * 	  u64			regs[weight(mask)]; } && PERF_SAMPLE_REGS_USER

tools/perf/builtin-script.c +37 -33

index e2406b291c1c..acf3107bbda2 100644
@@ -735,6 +735,7 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
  					struct perf_event_attr *attr, FILE *fp)
  {
  	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
  	struct addr_location alf, alt;
  	u64 i, from, to;
  	int printed = 0;

@@ -743,8 +744,8 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
  		return 0;
 
  	for (i = 0; i < br->nr; i++) {
-		from = br->entries[i].from;
-		to   = br->entries[i].to;
+		from = entries[i].from;
+		to   = entries[i].to;
 
  		if (PRINT_FIELD(DSO)) {
  			memset(&alf, 0, sizeof(alf));

@@ -768,10 +769,10 @@ static int perf_sample__fprintf_brstack(struct perf_sample *sample,
  		}
 
  		printed += fprintf(fp, "/%c/%c/%c/%d ",
-			mispred_str( br->entries + i),
-			br->entries[i].flags.in_tx? 'X' : '-',
-			br->entries[i].flags.abort? 'A' : '-',
-			br->entries[i].flags.cycles);
+			mispred_str(entries + i),
+			entries[i].flags.in_tx ? 'X' : '-',
+			entries[i].flags.abort ? 'A' : '-',
+			entries[i].flags.cycles);
  	}
 
  	return printed;

@@ -782,6 +783,7 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
  					   struct perf_event_attr *attr, FILE *fp)
  {
  	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
  	struct addr_location alf, alt;
  	u64 i, from, to;
  	int printed = 0;

@@ -793,8 +795,8 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
 
  		memset(&alf, 0, sizeof(alf));
  		memset(&alt, 0, sizeof(alt));
-		from = br->entries[i].from;
-		to   = br->entries[i].to;
+		from = entries[i].from;
+		to   = entries[i].to;
 
  		thread__find_symbol_fb(thread, sample->cpumode, from, &alf);
  		thread__find_symbol_fb(thread, sample->cpumode, to, &alt);

@@ -813,10 +815,10 @@ static int perf_sample__fprintf_brstacksym(struct perf_sample *sample,
  			printed += fprintf(fp, ")");
  		}
  		printed += fprintf(fp, "/%c/%c/%c/%d ",
-			mispred_str( br->entries + i),
-			br->entries[i].flags.in_tx? 'X' : '-',
-			br->entries[i].flags.abort? 'A' : '-',
-			br->entries[i].flags.cycles);
+			mispred_str(entries + i),
+			entries[i].flags.in_tx ? 'X' : '-',
+			entries[i].flags.abort ? 'A' : '-',
+			entries[i].flags.cycles);
  	}
 
  	return printed;

@@ -827,6 +829,7 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
  					   struct perf_event_attr *attr, FILE *fp)
  {
  	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
  	struct addr_location alf, alt;
  	u64 i, from, to;
  	int printed = 0;

@@ -838,8 +841,8 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
 
  		memset(&alf, 0, sizeof(alf));
  		memset(&alt, 0, sizeof(alt));
-		from = br->entries[i].from;
-		to   = br->entries[i].to;
+		from = entries[i].from;
+		to   = entries[i].to;
 
  		if (thread__find_map_fb(thread, sample->cpumode, from, &alf) &&
  		    !alf.map->dso->adjust_symbols)

@@ -862,10 +865,10 @@ static int perf_sample__fprintf_brstackoff(struct perf_sample *sample,
  			printed += fprintf(fp, ")");
  		}
  		printed += fprintf(fp, "/%c/%c/%c/%d ",
-			mispred_str(br->entries + i),
-			br->entries[i].flags.in_tx ? 'X' : '-',
-			br->entries[i].flags.abort ? 'A' : '-',
-			br->entries[i].flags.cycles);
+			mispred_str(entries + i),
+			entries[i].flags.in_tx ? 'X' : '-',
+			entries[i].flags.abort ? 'A' : '-',
+			entries[i].flags.cycles);
  	}
 
  	return printed;

@@ -1053,6 +1056,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
  					    struct machine *machine, FILE *fp)
  {
  	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
  	u64 start, end;
  	int i, insn, len, nr, ilen, printed = 0;
  	struct perf_insn x;

@@ -1073,31 +1077,31 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
  	printed += fprintf(fp, "%c", '\n');
 
  	/* Handle first from jump, of which we don't know the entry. */
-	len = grab_bb(buffer, br->entries[nr-1].from,
-			br->entries[nr-1].from,
+	len = grab_bb(buffer, entries[nr-1].from,
+			entries[nr-1].from,
  			machine, thread, &x.is64bit, &x.cpumode, false);
  	if (len > 0) {
-		printed += ip__fprintf_sym(br->entries[nr - 1].from, thread,
+		printed += ip__fprintf_sym(entries[nr - 1].from, thread,
  					   x.cpumode, x.cpu, &lastsym, attr, fp);
-		printed += ip__fprintf_jump(br->entries[nr - 1].from, &br->entries[nr - 1],
+		printed += ip__fprintf_jump(entries[nr - 1].from, &entries[nr - 1],
  					    &x, buffer, len, 0, fp, &total_cycles);
  		if (PRINT_FIELD(SRCCODE))
-			printed += print_srccode(thread, x.cpumode, br->entries[nr - 1].from);
+			printed += print_srccode(thread, x.cpumode, entries[nr - 1].from);
  	}
 
  	/* Print all blocks */
  	for (i = nr - 2; i >= 0; i--) {
-		if (br->entries[i].from || br->entries[i].to)
+		if (entries[i].from || entries[i].to)
  			pr_debug("%d: %" PRIx64 "-%" PRIx64 "\n", i,
-				 br->entries[i].from,
-				 br->entries[i].to);
-		start = br->entries[i + 1].to;
-		end   = br->entries[i].from;
+				 entries[i].from,
+				 entries[i].to);
+		start = entries[i + 1].to;
+		end   = entries[i].from;
 
  		len = grab_bb(buffer, start, end, machine, thread, &x.is64bit, &x.cpumode, false);
  		/* Patch up missing kernel transfers due to ring filters */
  		if (len == -ENXIO && i > 0) {
-			end = br->entries[--i].from;
+			end = entries[--i].from;
  			pr_debug("\tpatching up to %" PRIx64 "-%" PRIx64 "\n", start, end);
  			len = grab_bb(buffer, start, end, machine, thread, &x.is64bit, &x.cpumode, false);
  		}

@@ -1110,7 +1114,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
 
  			printed += ip__fprintf_sym(ip, thread, x.cpumode, x.cpu, &lastsym, attr, fp);
  			if (ip == end) {
-				printed += ip__fprintf_jump(ip, &br->entries[i], &x, buffer + off, len - off, ++insn, fp,
+				printed += ip__fprintf_jump(ip, &entries[i], &x, buffer + off, len - off, ++insn, fp,
  							    &total_cycles);
  				if (PRINT_FIELD(SRCCODE))
  					printed += print_srccode(thread, x.cpumode, ip);

@@ -1134,9 +1138,9 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
  	 * Hit the branch? In this case we are already done, and the target
  	 * has not been executed yet.
  	 */
-	if (br->entries[0].from == sample->ip)
+	if (entries[0].from == sample->ip)
  		goto out;
-	if (br->entries[0].flags.abort)
+	if (entries[0].flags.abort)
  		goto out;
 
  	/*

@@ -1147,7 +1151,7 @@ static int perf_sample__fprintf_brstackinsn(struct perf_sample *sample,
  	 * between final branch and sample. When this happens just
  	 * continue walking after the last TO until we hit a branch.
  	 */
-	start = br->entries[0].to;
+	start = entries[0].to;
  	end = sample->ip;
  	if (end < start) {
  		/* Missing jump. Scan 128 bytes for the next branch */

tools/perf/tests/sample-parsing.c +6 -1

index 2762e1155238..14239e472187 100644
@@ -99,6 +99,7 @@ static bool samples_same(const struct perf_sample *s1,
 
  	if (type & PERF_SAMPLE_BRANCH_STACK) {
  		COMP(branch_stack->nr);
+		COMP(branch_stack->hw_idx);
  		for (i = 0; i < s1->branch_stack->nr; i++)
  			MCOMP(branch_stack->entries[i]);
  	}

@@ -186,7 +187,7 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
  		u64 data[64];
  	} branch_stack = {
  		/* 1 branch_entry */
-		.data = {1, 211, 212, 213},
+		.data = {1, -1ULL, 211, 212, 213},
  	};
  	u64 regs[64];
  	const u64 raw_data[] = {0x123456780a0b0c0dULL, 0x1102030405060708ULL};

@@ -208,6 +209,7 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
  		.transaction	= 112,
  		.raw_data	= (void *)raw_data,
  		.callchain	= &callchain.callchain,
+		.no_hw_idx      = false,
  		.branch_stack	= &branch_stack.branch_stack,
  		.user_regs	= {
  			.abi	= PERF_SAMPLE_REGS_ABI_64,

@@ -244,6 +246,9 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format)
  	if (sample_type & PERF_SAMPLE_REGS_INTR)
  		evsel.core.attr.sample_regs_intr = sample_regs;
 
+	if (sample_type & PERF_SAMPLE_BRANCH_STACK)
+		evsel.core.attr.branch_sample_type |= PERF_SAMPLE_BRANCH_HW_INDEX;
+
  	for (i = 0; i < sizeof(regs); i++)
  		*(i + (u8 *)regs) = i & 0xfe;
 

tools/perf/util/branch.h +22 -0

index 88e00d268f6f..7fc9fa0dc361 100644
@@ -12,6 +12,7 @@
  #include <linux/stddef.h>
  #include <linux/perf_event.h>
  #include <linux/types.h>
+#include "event.h"
 
  struct branch_flags {
  	u64 mispred:1;

@@ -39,9 +40,30 @@ struct branch_entry {
 
  struct branch_stack {
  	u64			nr;
+	u64			hw_idx;
  	struct branch_entry	entries[0];
  };
 
+/*
+ * The hw_idx is only available when PERF_SAMPLE_BRANCH_HW_INDEX is applied.
+ * Otherwise, the output format of a sample with branch stack is
+ * struct branch_stack {
+ *	u64			nr;
+ *	struct branch_entry	entries[0];
+ * }
+ * Check whether the hw_idx is available,
+ * and return the corresponding pointer of entries[0].
+ */
+inline struct branch_entry *get_branch_entry(struct perf_sample *sample)
+{
+	u64 *entry = (u64 *)sample->branch_stack;
+
+	entry++;
+	if (sample->no_hw_idx)
+		return (struct branch_entry *)entry;
+	return (struct branch_entry *)(++entry);
+}
+
  struct branch_type_stat {
  	bool	branch_to;
  	u64	counts[PERF_BR_MAX];

tools/perf/util/cs-etm.c +0 -0

index 5471045ebf5c..e697fe1c67b3 100644

tools/perf/util/cs-etm.c static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq, · line 1208

Quoted 7 lines

tools/perf/util/cs-etm.c +1 -0

@@ -1202,6 +1202,7 @@ static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq,
  	if (etm->synth_opts.last_branch) {
  		dummy_bs = (struct dummy_branch_stack){
  			.nr = 1,
+			.hw_idx = -1ULL,
  			.entries = {
  				.from = sample.ip,
  				.to = sample.addr,

This one breaks the build when cross building to arm64:

   CC       /tmp/build/perf/util/cs-etm.o
   CC       /tmp/build/perf/util/parse-branch-options.o
   CC       /tmp/build/perf/util/dump-insn.o
util/cs-etm.c: In function 'cs_etm__synth_branch_sample':
util/cs-etm.c:1205:5: error: 'struct dummy_branch_stack' has no member named 'hw_idx'
     .hw_idx = -1ULL,
      ^~~~~~
util/cs-etm.c:1203:14: error: missing braces around initializer [-Werror=missing-braces]
    dummy_bs = (struct dummy_branch_stack){
               ^
util/cs-etm.c:1205:14:
     .hw_idx = -1ULL,
               {    }
util/cs-etm.c:1206:15: error: initialized field overwritten [-Werror=override-init]
     .entries = {
                ^
util/cs-etm.c:1206:15: note: (near initialization for '(anonymous).entries')
util/cs-etm.c:1203:14: error: missing braces around initializer [-Werror=missing-braces]
    dummy_bs = (struct dummy_branch_stack){
               ^
util/cs-etm.c:1205:14:
     .hw_idx = -1ULL,
               {    }

cc1: all warnings being treated as errors
mv: cannot stat '/tmp/build/perf/util/.cs-etm.o.tmp': No such file or directory

As that is 'struct dummy_branck_stack', not 'struct branch_stack', where you added that hw_idx, please check the logic, I'm adding the following quick fix and restarting the builds overnight, please check if this is the right thing to do.

- Arnaldo

tools/perf/util/cs-etm.c +1 -0

index e697fe1c67b3..b3b3fe3ea345 100644
@@ -1172,6 +1172,7 @@ static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq,
  	union perf_event *event = tidq->event_buf;
  	struct dummy_branch_stack {
  		u64			nr;
+		u64			hw_idx;
  		struct branch_entry	entries;
  	} dummy_bs;
  	u64 ip;

Quoted 345 lines

tools/perf/util/event.h +1 -0

index 85223159737c..3cda40a2fafc 100644
@@ -139,6 +139,7 @@ struct perf_sample {
  	u16 insn_len;
  	u8  cpumode;
  	u16 misc;
+	bool no_hw_idx;		/* No hw_idx collected in branch_stack */
  	char insn[MAX_INSN];
  	void *raw_data;
  	struct ip_callchain *callchain;

tools/perf/util/evsel.c +5 -0

index c8dc4450884c..05883a45de5b 100644
@@ -2169,7 +2169,12 @@ int perf_evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 
  		if (data->branch_stack->nr > max_branch_nr)
  			return -EFAULT;
+
  		sz = data->branch_stack->nr * sizeof(struct branch_entry);
+		if (perf_evsel__has_branch_hw_idx(evsel))
+			sz += sizeof(u64);
+		else
+			data->no_hw_idx = true;
  		OVERFLOW_CHECK(array, sz, max_size);
  		array = (void *)array + sz;
  	}

tools/perf/util/evsel.h +5 -0

index dc14f4a823cd..99a0cb60c556 100644
@@ -389,6 +389,11 @@ static inline bool perf_evsel__has_branch_callstack(const struct evsel *evsel)
  	return evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_CALL_STACK;
  }
 
+static inline bool perf_evsel__has_branch_hw_idx(const struct evsel *evsel)
+{
+	return evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX;
+}
+
  static inline bool evsel__has_callchain(const struct evsel *evsel)
  {
  	return (evsel->core.attr.sample_type & PERF_SAMPLE_CALLCHAIN) != 0;

tools/perf/util/hist.c +2 -1

index ca5a8f4d007e..808ca27bd5cf 100644
@@ -2584,9 +2584,10 @@ void hist__account_cycles(struct branch_stack *bs, struct addr_location *al,
  			  u64 *total_cycles)
  {
  	struct branch_info *bi;
+	struct branch_entry *entries = get_branch_entry(sample);
 
  	/* If we have branch cycles always annotate them. */
-	if (bs && bs->nr && bs->entries[0].flags.cycles) {
+	if (bs && bs->nr && entries[0].flags.cycles) {
  		int i;
 
  		bi = sample__resolve_bstack(sample, al);

tools/perf/util/intel-pt.c +2 -0

index 33cf8928cf05..23c8289c2472 100644
@@ -1295,6 +1295,7 @@ static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq)
  	struct perf_sample sample = { .ip = 0, };
  	struct dummy_branch_stack {
  		u64			nr;
+		u64			hw_idx;
  		struct branch_entry	entries;
  	} dummy_bs;
 

@@ -1316,6 +1317,7 @@ static int intel_pt_synth_branch_sample(struct intel_pt_queue *ptq)
  	if (pt->synth_opts.last_branch && sort__mode == SORT_MODE__BRANCH) {
  		dummy_bs = (struct dummy_branch_stack){
  			.nr = 1,
+			.hw_idx = -1ULL,
  			.entries = {
  				.from = sample.ip,
  				.to = sample.addr,

tools/perf/util/machine.c +18 -17

index c8c5410315e8..62522b76a924 100644
@@ -2083,15 +2083,16 @@ struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
  {
  	unsigned int i;
  	const struct branch_stack *bs = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
  	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));
 
  	if (!bi)
  		return NULL;
 
  	for (i = 0; i < bs->nr; i++) {
-		ip__resolve_ams(al->thread, &bi[i].to, bs->entries[i].to);
-		ip__resolve_ams(al->thread, &bi[i].from, bs->entries[i].from);
-		bi[i].flags = bs->entries[i].flags;
+		ip__resolve_ams(al->thread, &bi[i].to, entries[i].to);
+		ip__resolve_ams(al->thread, &bi[i].from, entries[i].from);
+		bi[i].flags = entries[i].flags;
  	}
  	return bi;
  }

@@ -2187,6 +2188,7 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
  	/* LBR only affects the user callchain */
  	if (i != chain_nr) {
  		struct branch_stack *lbr_stack = sample->branch_stack;
+		struct branch_entry *entries = get_branch_entry(sample);
  		int lbr_nr = lbr_stack->nr, j, k;
  		bool branch;
  		struct branch_flags *flags;

@@ -2212,31 +2214,29 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
  					ip = chain->ips[j];
  				else if (j > i + 1) {
  					k = j - i - 2;
-					ip = lbr_stack->entries[k].from;
+					ip = entries[k].from;
  					branch = true;
-					flags = &lbr_stack->entries[k].flags;
+					flags = &entries[k].flags;
  				} else {
-					ip = lbr_stack->entries[0].to;
+					ip = entries[0].to;
  					branch = true;
-					flags = &lbr_stack->entries[0].flags;
-					branch_from =
-						lbr_stack->entries[0].from;
+					flags = &entries[0].flags;
+					branch_from = entries[0].from;
  				}
  			} else {
  				if (j < lbr_nr) {
  					k = lbr_nr - j - 1;
-					ip = lbr_stack->entries[k].from;
+					ip = entries[k].from;
  					branch = true;
-					flags = &lbr_stack->entries[k].flags;
+					flags = &entries[k].flags;
  				}
  				else if (j > lbr_nr)
  					ip = chain->ips[i + 1 - (j - lbr_nr)];
  				else {
-					ip = lbr_stack->entries[0].to;
+					ip = entries[0].to;
  					branch = true;
-					flags = &lbr_stack->entries[0].flags;
-					branch_from =
-						lbr_stack->entries[0].from;
+					flags = &entries[0].flags;
+					branch_from = entries[0].from;
  				}
  			}
 

@@ -2283,6 +2283,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
  					    int max_stack)
  {
  	struct branch_stack *branch = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
  	struct ip_callchain *chain = sample->callchain;
  	int chain_nr = 0;
  	u8 cpumode = PERF_RECORD_MISC_USER;

@@ -2330,7 +2331,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
 
  		for (i = 0; i < nr; i++) {
  			if (callchain_param.order == ORDER_CALLEE) {
-				be[i] = branch->entries[i];
+				be[i] = entries[i];
 
  				if (chain == NULL)
  					continue;

@@ -2349,7 +2350,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
  				    be[i].from >= chain->ips[first_call] - 8)
  					first_call++;
  			} else
-				be[i] = branch->entries[branch->nr - i - 1];
+				be[i] = entries[branch->nr - i - 1];
  		}
 
  		memset(iter, 0, sizeof(struct iterations) * nr);

tools/perf/util/scripting-engines/trace-event-python.c +16 -14

index 80ca5d0ab7fe..02b6c87c5abe 100644
@@ -464,6 +464,7 @@ static PyObject *python_process_brstack(struct perf_sample *sample,
  					struct thread *thread)
  {
  	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
  	PyObject *pylist;
  	u64 i;
 

@@ -484,28 +485,28 @@ static PyObject *python_process_brstack(struct perf_sample *sample,
  			Py_FatalError("couldn't create Python dictionary");
 
  		pydict_set_item_string_decref(pyelem, "from",
-		    PyLong_FromUnsignedLongLong(br->entries[i].from));
+		    PyLong_FromUnsignedLongLong(entries[i].from));
  		pydict_set_item_string_decref(pyelem, "to",
-		    PyLong_FromUnsignedLongLong(br->entries[i].to));
+		    PyLong_FromUnsignedLongLong(entries[i].to));
  		pydict_set_item_string_decref(pyelem, "mispred",
-		    PyBool_FromLong(br->entries[i].flags.mispred));
+		    PyBool_FromLong(entries[i].flags.mispred));
  		pydict_set_item_string_decref(pyelem, "predicted",
-		    PyBool_FromLong(br->entries[i].flags.predicted));
+		    PyBool_FromLong(entries[i].flags.predicted));
  		pydict_set_item_string_decref(pyelem, "in_tx",
-		    PyBool_FromLong(br->entries[i].flags.in_tx));
+		    PyBool_FromLong(entries[i].flags.in_tx));
  		pydict_set_item_string_decref(pyelem, "abort",
-		    PyBool_FromLong(br->entries[i].flags.abort));
+		    PyBool_FromLong(entries[i].flags.abort));
  		pydict_set_item_string_decref(pyelem, "cycles",
-		    PyLong_FromUnsignedLongLong(br->entries[i].flags.cycles));
+		    PyLong_FromUnsignedLongLong(entries[i].flags.cycles));
 
  		thread__find_map_fb(thread, sample->cpumode,
-				    br->entries[i].from, &al);
+				    entries[i].from, &al);
  		dsoname = get_dsoname(al.map);
  		pydict_set_item_string_decref(pyelem, "from_dsoname",
  					      _PyUnicode_FromString(dsoname));
 
  		thread__find_map_fb(thread, sample->cpumode,
-				    br->entries[i].to, &al);
+				    entries[i].to, &al);
  		dsoname = get_dsoname(al.map);
  		pydict_set_item_string_decref(pyelem, "to_dsoname",
  					      _PyUnicode_FromString(dsoname));

@@ -561,6 +562,7 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
  					   struct thread *thread)
  {
  	struct branch_stack *br = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
  	PyObject *pylist;
  	u64 i;
  	char bf[512];

@@ -581,22 +583,22 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
  			Py_FatalError("couldn't create Python dictionary");
 
  		thread__find_symbol_fb(thread, sample->cpumode,
-				       br->entries[i].from, &al);
+				       entries[i].from, &al);
  		get_symoff(al.sym, &al, true, bf, sizeof(bf));
  		pydict_set_item_string_decref(pyelem, "from",
  					      _PyUnicode_FromString(bf));
 
  		thread__find_symbol_fb(thread, sample->cpumode,
-				       br->entries[i].to, &al);
+				       entries[i].to, &al);
  		get_symoff(al.sym, &al, true, bf, sizeof(bf));
  		pydict_set_item_string_decref(pyelem, "to",
  					      _PyUnicode_FromString(bf));
 
-		get_br_mspred(&br->entries[i].flags, bf, sizeof(bf));
+		get_br_mspred(&entries[i].flags, bf, sizeof(bf));
  		pydict_set_item_string_decref(pyelem, "pred",
  					      _PyUnicode_FromString(bf));
 
-		if (br->entries[i].flags.in_tx) {
+		if (entries[i].flags.in_tx) {
  			pydict_set_item_string_decref(pyelem, "in_tx",
  					      _PyUnicode_FromString("X"));
  		} else {

@@ -604,7 +606,7 @@ static PyObject *python_process_brstacksym(struct perf_sample *sample,
  					      _PyUnicode_FromString("-"));
  		}
 
-		if (br->entries[i].flags.abort) {
+		if (entries[i].flags.abort) {
  			pydict_set_item_string_decref(pyelem, "abort",
  					      _PyUnicode_FromString("A"));
  		} else {

tools/perf/util/session.c +5 -3

index d0d7d25b23e3..dab985e3f136 100644
@@ -1007,6 +1007,7 @@ static void callchain__lbr_callstack_printf(struct perf_sample *sample)
  {
  	struct ip_callchain *callchain = sample->callchain;
  	struct branch_stack *lbr_stack = sample->branch_stack;
+	struct branch_entry *entries = get_branch_entry(sample);
  	u64 kernel_callchain_nr = callchain->nr;
  	unsigned int i;
 

@@ -1043,10 +1044,10 @@ static void callchain__lbr_callstack_printf(struct perf_sample *sample)
  			       i, callchain->ips[i]);
 
  		printf("..... %2d: %016" PRIx64 "\n",
-		       (int)(kernel_callchain_nr), lbr_stack->entries[0].to);
+		       (int)(kernel_callchain_nr), entries[0].to);
  		for (i = 0; i < lbr_stack->nr; i++)
  			printf("..... %2d: %016" PRIx64 "\n",
-			       (int)(i + kernel_callchain_nr + 1), lbr_stack->entries[i].from);
+			       (int)(i + kernel_callchain_nr + 1), entries[i].from);
  	}
  }
 

@@ -1068,6 +1069,7 @@ static void callchain__printf(struct evsel *evsel,
 
  static void branch_stack__printf(struct perf_sample *sample, bool callstack)
  {
+	struct branch_entry *entries = get_branch_entry(sample);
  	uint64_t i;
 
  	printf("%s: nr:%" PRIu64 "\n",

@@ -1075,7 +1077,7 @@ static void branch_stack__printf(struct perf_sample *sample, bool callstack)
  		sample->branch_stack->nr);
 
  	for (i = 0; i < sample->branch_stack->nr; i++) {
-		struct branch_entry *e = &sample->branch_stack->entries[i];
+		struct branch_entry *e = &entries[i];
 
  		if (!callstack) {
  			printf("..... %2"PRIu64": %016" PRIx64 " -> %016" PRIx64 " %hu cycles %s%s%s%s %x\n",

tools/perf/util/synthetic-events.c +4 -2

index c423298fe62d..dd3e6f43fb86 100644
@@ -1183,7 +1183,8 @@ size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type,
 
  	if (type & PERF_SAMPLE_BRANCH_STACK) {
  		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
-		sz += sizeof(u64);
+		/* nr, hw_idx */
+		sz += 2 * sizeof(u64);
  		result += sz;
  	}
 

@@ -1344,7 +1345,8 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_fo
 
  	if (type & PERF_SAMPLE_BRANCH_STACK) {
  		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
-		sz += sizeof(u64);
+		/* nr, hw_idx */
+		sz += 2 * sizeof(u64);
  		memcpy(array, sample->branch_stack, sz);
  		array = (void *)array + sz;
  	}

Signature · 1 line

2.17.1

From: Kan Liang <[email protected]>

A new branch sample type PERF_SAMPLE_BRANCH_HW_INDEX has been introduced in latest kernel.

Enable HW_INDEX by default in LBR call stack mode. If kernel doesn't support the sample type, switching it off.

Add HW_INDEX in attr_fprintf as well. User can check whether the branch sample type is set via debug information or header.

Signed-off-by Kan Liang <[email protected]>

---
 tools/perf/util/evsel.c                   | 15 ++++++++++++---
 tools/perf/util/evsel.h                   |  1 +
 tools/perf/util/perf_event_attr_fprintf.c |  1 +
 3 files changed, 14 insertions(+), 3 deletions(-)

tools/perf/util/evsel.c +12 -3

index 05883a45de5b..816d930d774e 100644
@@ -712,7 +712,8 @@ static void __perf_evsel__config_callchain(struct evsel *evsel,
 				attr->branch_sample_type = PERF_SAMPLE_BRANCH_USER |
 							PERF_SAMPLE_BRANCH_CALL_STACK |
 							PERF_SAMPLE_BRANCH_NO_CYCLES |
-							PERF_SAMPLE_BRANCH_NO_FLAGS;
+							PERF_SAMPLE_BRANCH_NO_FLAGS |
+							PERF_SAMPLE_BRANCH_HW_INDEX;
 			}
 		} else
 			 pr_warning("Cannot use LBR callstack with branch stack. "

@@ -763,7 +764,8 @@ perf_evsel__reset_callgraph(struct evsel *evsel,
 	if (param->record_mode == CALLCHAIN_LBR) {
 		perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
 		attr->branch_sample_type &= ~(PERF_SAMPLE_BRANCH_USER |
-					      PERF_SAMPLE_BRANCH_CALL_STACK);
+					      PERF_SAMPLE_BRANCH_CALL_STACK |
+					      PERF_SAMPLE_BRANCH_HW_INDEX);
 	}
 	if (param->record_mode == CALLCHAIN_DWARF) {
 		perf_evsel__reset_sample_bit(evsel, REGS_USER);

@@ -1673,6 +1675,8 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 		evsel->core.attr.ksymbol = 0;
 	if (perf_missing_features.bpf)
 		evsel->core.attr.bpf_event = 0;
+	if (perf_missing_features.branch_hw_idx)
+		evsel->core.attr.branch_sample_type &= ~PERF_SAMPLE_BRANCH_HW_INDEX;
 retry_sample_id:
 	if (perf_missing_features.sample_id_all)
 		evsel->core.attr.sample_id_all = 0;

@@ -1784,7 +1788,12 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
 	 * Must probe features in the order they were added to the
 	 * perf_event_attr interface.
 	 */
-	if (!perf_missing_features.aux_output && evsel->core.attr.aux_output) {
+	if (!perf_missing_features.branch_hw_idx &&
+	    (evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX)) {
+		perf_missing_features.branch_hw_idx = true;
+		pr_debug2("switching off branch HW index support\n");
+		goto fallback_missing_features;
+	} else if (!perf_missing_features.aux_output && evsel->core.attr.aux_output) {
 		perf_missing_features.aux_output = true;
 		pr_debug2_peo("Kernel has no attr.aux_output support, bailing out\n");
 		goto out_close;

tools/perf/util/evsel.h +1 -0

index 99a0cb60c556..33804740e2ca 100644
@@ -119,6 +119,7 @@ struct perf_missing_features {
 	bool ksymbol;
 	bool bpf;
 	bool aux_output;
+	bool branch_hw_idx;
 };
 
 extern struct perf_missing_features perf_missing_features;

tools/perf/util/perf_event_attr_fprintf.c +1 -0

index 651203126c71..355d3458d4e6 100644
@@ -50,6 +50,7 @@ static void __p_branch_sample_type(char *buf, size_t size, u64 value)
 		bit_name(ABORT_TX), bit_name(IN_TX), bit_name(NO_TX),
 		bit_name(COND), bit_name(CALL_STACK), bit_name(IND_JUMP),
 		bit_name(CALL), bit_name(NO_FLAGS), bit_name(NO_CYCLES),
+		bit_name(HW_INDEX),
 		{ .name = NULL, }
 	};
 #undef bit_name

Signature · 1 line

2.17.1