[PATCH v3 4/7] perf diff: Use hists to manage basic blocks per symbol

From: Jin Yao
Date: Mon Jun 17 2019 - 01:06:30 EST


The hist__account_cycles() can account cycles per basic
block. The basic block information is saved in cycles_hist
structure.

This patch processes each symbol, get basic blocks from
cycles_hist and add the basic block entries to a new hists
(in 'struct block_hist'). Using a hists is because
we need to compare, sort and print the basic blocks later.

v3:
---
1. In v2, we put block stuffs in 'struct hist_entry', but
it's not a good design. In v3, we create a new
'struct block_hist' and cast the 'struct hist_entry' to
'struct block_hist' in some places, which can avoid adding
new stuffs in 'struct hist_entry'.

2. abs() -> labs(), in block_cycles_diff_cmp().

v2:
---
v1 adds the basic block entries to per data-file hists
but v2 adds the basic block entries to per symbol hists.
That is to keep current perf-diff format. Will show the
result in next patches.

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
tools/perf/builtin-diff.c | 209 +++++++++++++++++++++++++++++++++++++++++++++-
tools/perf/util/sort.h | 12 +++
2 files changed, 218 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index a7e0420..c6ec84d 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -20,6 +20,7 @@
#include "util/data.h"
#include "util/config.h"
#include "util/time-utils.h"
+#include "util/annotate.h"

#include <errno.h>
#include <inttypes.h>
@@ -87,11 +88,14 @@ static s64 compute_wdiff_w2;
static const char *cpu_list;
static DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);

+static struct addr_location dummy_al;
+
enum {
COMPUTE_DELTA,
COMPUTE_RATIO,
COMPUTE_WEIGHTED_DIFF,
COMPUTE_DELTA_ABS,
+ COMPUTE_CYCLES,
COMPUTE_MAX,
};

@@ -100,6 +104,7 @@ const char *compute_names[COMPUTE_MAX] = {
[COMPUTE_DELTA_ABS] = "delta-abs",
[COMPUTE_RATIO] = "ratio",
[COMPUTE_WEIGHTED_DIFF] = "wdiff",
+ [COMPUTE_CYCLES] = "cycles",
};

static int compute = COMPUTE_DELTA_ABS;
@@ -234,6 +239,8 @@ static int setup_compute(const struct option *opt, const char *str,
for (i = 0; i < COMPUTE_MAX; i++)
if (!strcmp(cstr, compute_names[i])) {
*cp = i;
+ if (i == COMPUTE_CYCLES)
+ break;
return setup_compute_opt(option);
}

@@ -336,6 +343,31 @@ static int formula_fprintf(struct hist_entry *he, struct hist_entry *pair,
return -1;
}

+static void *block_hist_zalloc(size_t size)
+{
+ struct block_hist *bh;
+
+ bh = zalloc(size + sizeof(*bh));
+ if (!bh)
+ return NULL;
+
+ return &bh->he;
+}
+
+static void block_hist_free(void *he)
+{
+ struct block_hist *bh;
+
+ bh = container_of(he, struct block_hist, he);
+ hists__delete_entries(&bh->block_hists);
+ free(bh);
+}
+
+struct hist_entry_ops block_hist_ops = {
+ .new = block_hist_zalloc,
+ .free = block_hist_free,
+};
+
static int diff__process_sample_event(struct perf_tool *tool,
union perf_event *event,
struct perf_sample *sample,
@@ -363,9 +395,22 @@ static int diff__process_sample_event(struct perf_tool *tool,
goto out_put;
}

- if (!hists__add_entry(hists, &al, NULL, NULL, NULL, sample, true)) {
- pr_warning("problem incrementing symbol period, skipping event\n");
- goto out_put;
+ if (compute != COMPUTE_CYCLES) {
+ if (!hists__add_entry(hists, &al, NULL, NULL, NULL, sample,
+ true)) {
+ pr_warning("problem incrementing symbol period, "
+ "skipping event\n");
+ goto out_put;
+ }
+ } else {
+ if (!hists__add_entry_ops(hists, &block_hist_ops, &al, NULL,
+ NULL, NULL, sample, true)) {
+ pr_warning("problem incrementing symbol period, "
+ "skipping event\n");
+ goto out_put;
+ }
+
+ hist__account_cycles(sample->branch_stack, &al, sample, false);
}

/*
@@ -475,6 +520,146 @@ static void hists__baseline_only(struct hists *hists)
}
}

+static int64_t block_cmp(struct perf_hpp_fmt *fmt __maybe_unused,
+ struct hist_entry *left, struct hist_entry *right)
+{
+ struct block_info *bi_l = left->block_info;
+ struct block_info *bi_r = right->block_info;
+ int cmp;
+
+ if (!bi_l->sym || !bi_r->sym) {
+ if (!bi_l->sym && !bi_r->sym)
+ return 0;
+ else if (!bi_l->sym)
+ return -1;
+ else
+ return 1;
+ }
+
+ if (bi_l->sym == bi_r->sym) {
+ if (bi_l->start == bi_r->start) {
+ if (bi_l->end == bi_r->end)
+ return 0;
+ else
+ return (int64_t)(bi_r->end - bi_l->end);
+ } else
+ return (int64_t)(bi_r->start - bi_l->start);
+ } else {
+ cmp = strcmp(bi_l->sym->name, bi_r->sym->name);
+ return cmp;
+ }
+
+ if (bi_l->sym->start != bi_r->sym->start)
+ return (int64_t)(bi_r->sym->start - bi_l->sym->start);
+
+ return (int64_t)(bi_r->sym->end - bi_l->sym->end);
+}
+
+static int64_t block_cycles_diff_cmp(struct hist_entry *left,
+ struct hist_entry *right)
+{
+ bool pairs_left = hist_entry__has_pairs(left);
+ bool pairs_right = hist_entry__has_pairs(right);
+ s64 l, r;
+
+ if (!pairs_left && !pairs_right)
+ return 0;
+
+ l = labs(left->diff.cycles);
+ r = labs(right->diff.cycles);
+ return r - l;
+}
+
+static int64_t block_sort(struct perf_hpp_fmt *fmt __maybe_unused,
+ struct hist_entry *left, struct hist_entry *right)
+{
+ return block_cycles_diff_cmp(right, left);
+}
+
+static void init_block_hist(struct block_hist *bh)
+{
+ __hists__init(&bh->block_hists, &bh->block_list);
+ perf_hpp_list__init(&bh->block_list);
+
+ INIT_LIST_HEAD(&bh->block_fmt.list);
+ INIT_LIST_HEAD(&bh->block_fmt.sort_list);
+ bh->block_fmt.cmp = block_cmp;
+ bh->block_fmt.sort = block_sort;
+ perf_hpp_list__register_sort_field(&bh->block_list,
+ &bh->block_fmt);
+ bh->valid = true;
+}
+
+static void init_block_info(struct block_info *bi, struct symbol *sym,
+ struct cyc_hist *ch, int offset)
+{
+ bi->sym = sym;
+ bi->start = ch->start;
+ bi->end = offset;
+ bi->cycles = ch->cycles;
+ bi->cycles_aggr = ch->cycles_aggr;
+ bi->num = ch->num;
+ bi->num_aggr = ch->num_aggr;
+}
+
+static void *block_entry_zalloc(size_t size)
+{
+ return zalloc(size + sizeof(struct hist_entry));
+}
+
+static void block_entry_free(void *he)
+{
+ struct block_info *bi = ((struct hist_entry *)he)->block_info;
+
+ block_info__put(bi);
+ free(he);
+}
+
+struct hist_entry_ops block_entry_ops = {
+ .new = block_entry_zalloc,
+ .free = block_entry_free,
+};
+
+static int process_block_per_sym(struct hist_entry *he)
+{
+ struct annotation *notes;
+ struct cyc_hist *ch;
+ struct block_hist *bh;
+
+ if (!he->ms.map || !he->ms.sym)
+ return 0;
+
+ notes = symbol__annotation(he->ms.sym);
+ if (!notes || !notes->src || !notes->src->cycles_hist)
+ return 0;
+
+ bh = container_of(he, struct block_hist, he);
+ init_block_hist(bh);
+
+ ch = notes->src->cycles_hist;
+ for (unsigned int i = 0; i < symbol__size(he->ms.sym); i++) {
+ if (ch[i].num_aggr) {
+ struct block_info *bi;
+ struct hist_entry *he_block;
+
+ bi = block_info__new();
+ if (!bi)
+ return -1;
+
+ init_block_info(bi, he->ms.sym, &ch[i], i);
+ he_block = hists__add_entry_block(&bh->block_hists,
+ &block_entry_ops,
+ &dummy_al, bi);
+ if (!he_block) {
+ block_info__put(bi);
+ return -1;
+ }
+ }
+ }
+
+ return 0;
+}
+
static void hists__precompute(struct hists *hists)
{
struct rb_root_cached *root;
@@ -494,6 +679,9 @@ static void hists__precompute(struct hists *hists)
he = rb_entry(next, struct hist_entry, rb_node_in);
next = rb_next(&he->rb_node_in);

+ if (compute == COMPUTE_CYCLES)
+ process_block_per_sym(he);
+
data__for_each_file_new(i, d) {
pair = get_pair_data(he, d);
if (!pair)
@@ -510,6 +698,9 @@ static void hists__precompute(struct hists *hists)
case COMPUTE_WEIGHTED_DIFF:
compute_wdiff(he, pair);
break;
+ case COMPUTE_CYCLES:
+ process_block_per_sym(pair);
+ break;
default:
BUG_ON(1);
}
@@ -1411,6 +1602,13 @@ static int ui_init(void)
case COMPUTE_DELTA_ABS:
fmt->sort = hist_entry__cmp_delta_abs_idx;
break;
+ case COMPUTE_CYCLES:
+ /*
+ * Should set since 'fmt->sort' is called without
+ * checking valid during sorting
+ */
+ fmt->sort = hist_entry__cmp_nop;
+ break;
default:
BUG_ON(1);
}
@@ -1507,6 +1705,8 @@ int cmd_diff(int argc, const char **argv)
if (quiet)
perf_quiet_option();

+ symbol__annotation_init();
+
if (symbol__init(NULL) < 0)
return -1;

@@ -1516,6 +1716,9 @@ int cmd_diff(int argc, const char **argv)
if (check_file_brstack() < 0)
return -1;

+ if (compute == COMPUTE_CYCLES && !pdiff.has_br_stack)
+ return -1;
+
if (ui_init() < 0)
return -1;

diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index 43623fa..a0f2321 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -79,6 +79,9 @@ struct hist_entry_diff {

/* HISTC_WEIGHTED_DIFF */
s64 wdiff;
+
+ /* PERF_HPP_DIFF__CYCLES */
+ s64 cycles;
};
};

@@ -286,6 +289,15 @@ struct sort_entry {
u8 se_width_idx;
};

+struct block_hist {
+ struct hists block_hists;
+ struct perf_hpp_list block_list;
+ struct perf_hpp_fmt block_fmt;
+ int block_idx;
+ bool valid;
+ struct hist_entry he;
+};
+
extern struct sort_entry sort_thread;
extern struct list_head hist_entry__sort_list;

--
2.7.4