[PATCH 6/9] perf report: Display the branch counter histogram

kan.liang
2024-07-03T20:03:27Z

From: Kan Liang <kan.liang@linux.intel.com>

Reusing the existing --total-cycles option to display the branch
counters. Add a new PERF_HPP_REPORT__BLOCK_BRANCH_COUNTER to display
the logged branch counter events. They are shown right after all the
cycle-related annotations.
Extend the struct block_info to store and pass the branch counter
related information.

The annotation_br_cntr_entry() is to print the histogram of each branch
counter event.
The annotation_br_cntr_abbr_list() prints the branch counter's
abbreviation list. Press 'B' to display the list in the TUI mode.

$perf record -e "{branch-instructions:ppp,branch-misses}:S" -j any,counter
$perf report --total-cycles --stdio

# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 1M of events 'anon group { branch-instructions:ppp, branch-misses }'
# Event count (approx.): 1610046
#
# Branch counter abbr list:
# branch-instructions:ppp = A
# branch-misses = B
# '-' No event occurs
# '+' Event occurrences may be lost due to branch counter saturated
#
# Sampled Cycles% Sampled Cycles Avg Cycles% Avg Cycles Branch Counter [Program Block Range]
# ............... .............. ........... .......... ...................... ..................
#
57.55% 2.5M 0.00% 3 |A |- | ...
25.27% 1.1M 0.00% 2 |AA |- | ...
15.61% 667.2K 0.00% 1 |A |- | ...
0.16% 6.9K 0.81% 575 |A |- | ...
0.16% 6.8K 1.38% 977 |AA |- | ...
0.16% 6.8K 0.04% 28 |AA |B | ...
0.15% 6.6K 1.33% 946 |A |- | ...
0.11% 4.5K 0.06% 46 |AAA+|- | ...
0.10% 4.4K 0.88% 624 |A |- | ...
0.09% 3.7K 0.74% 524 |AAA+|B | ...

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
tools/perf/Documentation/perf-report.txt | 1 +
tools/perf/builtin-diff.c | 4 +-
tools/perf/builtin-report.c | 20 ++++-
tools/perf/ui/browsers/hists.c | 17 +++-
tools/perf/util/annotate.c | 101 +++++++++++++++++++++++
tools/perf/util/annotate.h | 3 +
tools/perf/util/block-info.c | 66 +++++++++++++--
tools/perf/util/block-info.h | 8 +-
8 files changed, 202 insertions(+), 18 deletions(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index d2b1593ef700..f35189d5ff1e 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -614,6 +614,7 @@ include::itrace.txt[]
'Avg Cycles%' - block average sampled cycles / sum of total block average
sampled cycles
'Avg Cycles' - block average sampled cycles
+ 'Branch Counter' - block branch counter histogram

--skip-empty::
Do not print 0 results in the --stat output.
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 2d9226b1de52..de24892dc7b8 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -705,7 +705,7 @@ static void hists__precompute(struct hists *hists)
if (compute == COMPUTE_CYCLES) {
bh = container_of(he, struct block_hist, he);
init_block_hist(bh);
- block_info__process_sym(he, bh, NULL, 0);
+ block_info__process_sym(he, bh, NULL, 0, 0);
}

data__for_each_file_new(i, d) {
@@ -728,7 +728,7 @@ static void hists__precompute(struct hists *hists)
pair_bh = container_of(pair, struct block_hist,
he);
init_block_hist(pair_bh);
- block_info__process_sym(pair, pair_bh, NULL, 0);
+ block_info__process_sym(pair, pair_bh, NULL, 0, 0);

bh = container_of(he, struct block_hist, he);

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index da8d13bbb500..a0f864f2e996 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -575,6 +575,13 @@ static int evlist__tty_browse_hists(struct evlist *evlist, struct report *rep, c
hists__fprintf_nr_sample_events(hists, rep, evname, stdout);

if (rep->total_cycles_mode) {
+ char *buf;
+
+ if (!annotation_br_cntr_abbr_list(&buf, pos, true)) {
+ fprintf(stdout, "%s", buf);
+ fprintf(stdout, "#\n");
+ free(buf);
+ }
report__browse_block_hists(&rep->block_reports[i - 1].hist,
rep->min_percent, pos, NULL);
continue;
@@ -1121,18 +1128,23 @@ static int __cmd_report(struct report *rep)
report__output_resort(rep);

if (rep->total_cycles_mode) {
- int block_hpps[6] = {
+ int nr_hpps = 4;
+ int block_hpps[PERF_HPP_REPORT__BLOCK_MAX_INDEX] = {
PERF_HPP_REPORT__BLOCK_TOTAL_CYCLES_PCT,
PERF_HPP_REPORT__BLOCK_LBR_CYCLES,
PERF_HPP_REPORT__BLOCK_CYCLES_PCT,
PERF_HPP_REPORT__BLOCK_AVG_CYCLES,
- PERF_HPP_REPORT__BLOCK_RANGE,
- PERF_HPP_REPORT__BLOCK_DSO,
};

+ if (session->evlist->nr_br_cntr > 0)
+ block_hpps[nr_hpps++] = PERF_HPP_REPORT__BLOCK_BRANCH_COUNTER;
+
+ block_hpps[nr_hpps++] = PERF_HPP_REPORT__BLOCK_RANGE;
+ block_hpps[nr_hpps++] = PERF_HPP_REPORT__BLOCK_DSO;
+
rep->block_reports = block_info__create_report(session->evlist,
rep->total_cycles,
- block_hpps, 6,
+ block_hpps, nr_hpps,
&rep->nr_block_reports);
if (!rep->block_reports)
return -1;
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index b7219df51236..73d766eac75b 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -3684,8 +3684,10 @@ int block_hists_tui_browse(struct block_hist *bh, struct evsel *evsel,
struct hist_browser *browser;
int key = -1;
struct popup_action action;
+ char *br_cntr_text = NULL;
static const char help[] =
- " q Quit \n";
+ " q Quit \n"
+ " B Branch counter abbr list (Optional)\n";

browser = hist_browser__new(hists);
if (!browser)
@@ -3703,6 +3705,8 @@ int block_hists_tui_browse(struct block_hist *bh, struct evsel *evsel,

memset(&action, 0, sizeof(action));

+ annotation_br_cntr_abbr_list(&br_cntr_text, evsel, false);
+
while (1) {
key = hist_browser__run(browser, "? - help", true, 0);

@@ -3723,6 +3727,16 @@ int block_hists_tui_browse(struct block_hist *bh, struct evsel *evsel,
action.ms.sym = browser->selection->sym;
do_annotate(browser, &action);
continue;
+ case 'B':
+ if (br_cntr_text) {
+ ui__question_window("Branch counter abbr list",
+ br_cntr_text, "Press any key...", 0);
+ } else {
+ ui__question_window("Branch counter abbr list",
+ "\n The branch counter is not available.\n",
+ "Press any key...", 0);
+ }
+ continue;
default:
break;
}
@@ -3730,5 +3744,6 @@ int block_hists_tui_browse(struct block_hist *bh, struct evsel *evsel,

out:
hist_browser__delete(browser);
+ free(br_cntr_text);
return 0;
}
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 6baa0671598e..f20f9e40ef0d 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -40,6 +40,7 @@
#include "namespaces.h"
#include "thread.h"
#include "hashmap.h"
+#include "strbuf.h"
#include <regex.h>
#include <linux/bitops.h>
#include <linux/kernel.h>
@@ -47,6 +48,7 @@
#include <linux/zalloc.h>
#include <subcmd/parse-options.h>
#include <subcmd/run-command.h>
+#include <math.h>

/* FIXME: For the HE_COLORSET */
#include "ui/browser.h"
@@ -1706,6 +1708,105 @@ static void ipc_coverage_string(char *bf, int size, struct annotation *notes)
ipc, coverage);
}

+int annotation_br_cntr_abbr_list(char **str, struct evsel *evsel, bool header)
+{
+ struct evsel *pos;
+ struct strbuf sb;
+
+ if (evsel->evlist->nr_br_cntr <= 0)
+ return -ENOTSUP;
+
+ strbuf_init(&sb, /*hint=*/ 0);
+
+ if (header && strbuf_addf(&sb, "# Branch counter abbr list:\n"))
+ goto err;
+
+ evlist__for_each_entry(evsel->evlist, pos) {
+ if (!(pos->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_COUNTERS))
+ continue;
+ if (header && strbuf_addf(&sb, "#"))
+ goto err;
+
+ if (strbuf_addf(&sb, " %s = %s\n", pos->name, pos->abbr_name))
+ goto err;
+ }
+
+ if (header && strbuf_addf(&sb, "#"))
+ goto err;
+ if (strbuf_addf(&sb, " '-' No event occurs\n"))
+ goto err;
+
+ if (header && strbuf_addf(&sb, "#"))
+ goto err;
+ if (strbuf_addf(&sb, " '+' Event occurrences may be lost due to branch counter saturated\n"))
+ goto err;
+
+ *str = strbuf_detach(&sb, NULL);
+
+ return 0;
+err:
+ strbuf_release(&sb);
+ return -ENOMEM;
+}
+
+int annotation_br_cntr_entry(char **str, int br_cntr_nr,
+ u64 *br_cntr, int num_aggr,
+ struct evsel *evsel)
+{
+ struct evsel *pos = evsel ? evlist__first(evsel->evlist) : NULL;
+ int i, j, avg, used;
+ struct strbuf sb;
+
+ strbuf_init(&sb, /*hint=*/ 0);
+ for (i = 0; i < br_cntr_nr; i++) {
+ used = 0;
+ avg = ceil((double)(br_cntr[i] & ~ANNOTATION__BR_CNTR_SATURATED_FLAG) /
+ (double)num_aggr);
+
+ if (strbuf_addch(&sb, '|'))
+ goto err;
+
+ if (!br_cntr[i]) {
+ if (strbuf_addch(&sb, '-'))
+ goto err;
+ used++;
+ } else {
+ evlist__for_each_entry_from(evsel->evlist, pos) {
+ if ((pos->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_COUNTERS) &&
+ (pos->br_cntr_idx == i))
+ break;
+ }
+ for (j = 0; j < avg; j++, used++) {
+ if (strbuf_addstr(&sb, pos->abbr_name))
+ goto err;
+ }
+
+ if (br_cntr[i] & ANNOTATION__BR_CNTR_SATURATED_FLAG) {
+ if (strbuf_addch(&sb, '+'))
+ goto err;
+ used++;
+ }
+ pos = list_next_entry(pos, core.node);
+ }
+
+ /* Assume the branch counter saturated at 3 */
+ for (j = used; j < 4; j++) {
+ if (strbuf_addch(&sb, ' '))
+ goto err;
+ }
+ }
+
+ if (strbuf_addch(&sb, br_cntr_nr ? '|' : ' '))
+ goto err;
+
+ *str = strbuf_detach(&sb, NULL);
+
+ return 0;
+err:
+ strbuf_release(&sb);
+ return -ENOMEM;
+}
+
static void __annotation_line__write(struct annotation_line *al, struct annotation *notes,
bool first_line, bool current_entry, bool change_color, int width,
void *obj, unsigned int percent_type,
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index f39dd5d7b05e..2ff79a389dc0 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -548,4 +548,7 @@ struct annotated_basic_block {
int annotate_get_basic_blocks(struct symbol *sym, s64 src, s64 dst,
struct list_head *head);

+int annotation_br_cntr_entry(char **str, int br_cntr_nr, u64 *br_cntr,
+ int num_aggr, struct evsel *evsel);
+int annotation_br_cntr_abbr_list(char **str, struct evsel *evsel, bool header);
#endif /* __PERF_ANNOTATE_H */
diff --git a/tools/perf/util/block-info.c b/tools/perf/util/block-info.c
index 04068d48683f..649392bee7ed 100644
--- a/tools/perf/util/block-info.c
+++ b/tools/perf/util/block-info.c
@@ -40,16 +40,32 @@ static struct block_header_column {
[PERF_HPP_REPORT__BLOCK_DSO] = {
.name = "Shared Object",
.width = 20,
+ },
+ [PERF_HPP_REPORT__BLOCK_BRANCH_COUNTER] = {
+ .name = "Branch Counter",
+ .width = 30,
}
};

-struct block_info *block_info__new(void)
+static struct block_info *block_info__new(unsigned int br_cntr_nr)
{
- return zalloc(sizeof(struct block_info));
+ struct block_info *bi = zalloc(sizeof(struct block_info));
+
+ if (bi && br_cntr_nr) {
+ bi->br_cntr = calloc(br_cntr_nr, sizeof(u64));
+ if (!bi->br_cntr) {
+ free(bi);
+ return NULL;
+ }
+ }
+
+ return bi;
}

void block_info__delete(struct block_info *bi)
{
+ if (bi)
+ free(bi->br_cntr);
free(bi);
}

@@ -86,7 +102,8 @@ int64_t block_info__cmp(struct perf_hpp_fmt *fmt __maybe_unused,

static void init_block_info(struct block_info *bi, struct symbol *sym,
struct cyc_hist *ch, int offset,
- u64 total_cycles)
+ u64 total_cycles, unsigned int br_cntr_nr,
+ u64 *br_cntr, struct evsel *evsel)
{
bi->sym = sym;
bi->start = ch->start;
@@ -99,10 +116,18 @@ static void init_block_info(struct block_info *bi, struct symbol *sym,

memcpy(bi->cycles_spark, ch->cycles_spark,
NUM_SPARKS * sizeof(u64));
+
+ if (br_cntr && br_cntr_nr) {
+ bi->br_cntr_nr = br_cntr_nr;
+ memcpy(bi->br_cntr, &br_cntr[offset * br_cntr_nr],
+ br_cntr_nr * sizeof(u64));
+ }
+ bi->evsel = evsel;
}

int block_info__process_sym(struct hist_entry *he, struct block_hist *bh,
- u64 *block_cycles_aggr, u64 total_cycles)
+ u64 *block_cycles_aggr, u64 total_cycles,
+ unsigned int br_cntr_nr)
{
struct annotation *notes;
struct cyc_hist *ch;
@@ -125,12 +150,14 @@ int block_info__process_sym(struct hist_entry *he, struct block_hist *bh,
struct block_info *bi;
struct hist_entry *he_block;

- bi = block_info__new();
+ bi = block_info__new(br_cntr_nr);
if (!bi)
return -1;

init_block_info(bi, he->ms.sym, &ch[i], i,
- total_cycles);
+ total_cycles, br_cntr_nr,
+ notes->branch->br_cntr,
+ hists_to_evsel(he->hists));
cycles += bi->cycles_aggr / bi->num_aggr;

he_block = hists__add_entry_block(&bh->block_hists,
@@ -327,6 +354,24 @@ static void init_block_header(struct block_fmt *block_fmt)
fmt->width = block_column_width;
}

+static int block_branch_counter_entry(struct perf_hpp_fmt *fmt,
+ struct perf_hpp *hpp,
+ struct hist_entry *he)
+{
+ struct block_fmt *block_fmt = container_of(fmt, struct block_fmt, fmt);
+ struct block_info *bi = he->block_info;
+ char *buf;
+ int ret;
+
+ if (annotation_br_cntr_entry(&buf, bi->br_cntr_nr, bi->br_cntr,
+ bi->num_aggr, bi->evsel))
+ return 0;
+
+ ret = scnprintf(hpp->buf, hpp->size, "%*s", block_fmt->width, buf);
+ free(buf);
+ return ret;
+}
+
static void hpp_register(struct block_fmt *block_fmt, int idx,
struct perf_hpp_list *hpp_list)
{
@@ -357,6 +402,9 @@ static void hpp_register(struct block_fmt *block_fmt, int idx,
case PERF_HPP_REPORT__BLOCK_DSO:
fmt->entry = block_dso_entry;
break;
+ case PERF_HPP_REPORT__BLOCK_BRANCH_COUNTER:
+ fmt->entry = block_branch_counter_entry;
+ break;
default:
return;
}
@@ -390,7 +438,7 @@ static void init_block_hist(struct block_hist *bh, struct block_fmt *block_fmts,
static int process_block_report(struct hists *hists,
struct block_report *block_report,
u64 total_cycles, int *block_hpps,
- int nr_hpps)
+ int nr_hpps, unsigned int br_cntr_nr)
{
struct rb_node *next = rb_first_cached(&hists->entries);
struct block_hist *bh = &block_report->hist;
@@ -405,7 +453,7 @@ static int process_block_report(struct hists *hists,
while (next) {
he = rb_entry(next, struct hist_entry, rb_node);
block_info__process_sym(he, bh, &block_report->cycles,
- total_cycles);
+ total_cycles, br_cntr_nr);
next = rb_next(&he->rb_node);
}

@@ -435,7 +483,7 @@ struct block_report *block_info__create_report(struct evlist *evlist,
struct hists *hists = evsel__hists(pos);

process_block_report(hists, &block_reports[i], total_cycles,
- block_hpps, nr_hpps);
+ block_hpps, nr_hpps, evlist->nr_br_cntr);
i++;
}

diff --git a/tools/perf/util/block-info.h b/tools/perf/util/block-info.h
index 0b9e1aad4c55..b9329dc3ab59 100644
--- a/tools/perf/util/block-info.h
+++ b/tools/perf/util/block-info.h
@@ -18,6 +18,9 @@ struct block_info {
u64 total_cycles;
int num;
int num_aggr;
+ int br_cntr_nr;
+ u64 *br_cntr;
+ struct evsel *evsel;
};

struct block_fmt {
@@ -36,6 +39,7 @@ enum {
PERF_HPP_REPORT__BLOCK_AVG_CYCLES,
PERF_HPP_REPORT__BLOCK_RANGE,
PERF_HPP_REPORT__BLOCK_DSO,
+ PERF_HPP_REPORT__BLOCK_BRANCH_COUNTER,
PERF_HPP_REPORT__BLOCK_MAX_INDEX
};

@@ -46,7 +50,6 @@ struct block_report {
int nr_fmts;
};

-struct block_info *block_info__new(void);
void block_info__delete(struct block_info *bi);

int64_t __block_info__cmp(struct hist_entry *left, struct hist_entry *right);
@@ -55,7 +58,8 @@ int64_t block_info__cmp(struct perf_hpp_fmt *fmt __maybe_unused,
struct hist_entry *left, struct hist_entry *right);

int block_info__process_sym(struct hist_entry *he, struct block_hist *bh,
- u64 *block_cycles_aggr, u64 total_cycles);
+ u64 *block_cycles_aggr, u64 total_cycles,
+ unsigned int br_cntr_nr);

struct block_report *block_info__create_report(struct evlist *evlist,
u64 total_cycles,
--
2.38.1