[PATCH v3 1/3] perf annotate: Compute average IPC and IPC coverage per symbol

Jin Yao
2018-11-28T07:23:30Z

Add support to perf report annotate view or perf annotate --stdio2 to
aggregate the IPC derived from timed LBRs per symbol. We compute the
average IPC and the IPC coverage percentage.

For example,

$ perf annotate --stdio2

Percent IPC Cycle (Average IPC: 2.30, IPC Coverage: 54.8%)

Disassembly of section .text:

000000000003aac0 <random@@GLIBC_2.2.5>:
8.32 3.28 sub $0x18,%rsp
3.28 mov $0x1,%esi
3.28 xor %eax,%eax
3.28 cmpl $0x0,argp_program_version_hook@@GLIBC_2.2.5+0x1e0
11.57 3.28 1 ↓ je 20
lock cmpxchg %esi,__abort_msg@@GLIBC_PRIVATE+0x8a0
↓ jne 29
↓ jmp 43
11.57 1.10 20: cmpxchg %esi,__abort_msg@@GLIBC_PRIVATE+0x8a0
0.00 1.10 1 ↓ je 43
29: lea __abort_msg@@GLIBC_PRIVATE+0x8a0,%rdi
sub $0x80,%rsp
→ callq __lll_lock_wait_private
add $0x80,%rsp
0.00 3.00 43: lea __ctype_b@GLIBC_2.2.5+0x38,%rdi
3.00 lea 0xc(%rsp),%rsi
8.49 3.00 1 → callq __random_r
7.91 1.94 cmpl $0x0,argp_program_version_hook@@GLIBC_2.2.5+0x1e0
0.00 1.94 1 ↓ je 68
lock decl __abort_msg@@GLIBC_PRIVATE+0x8a0
↓ jne 70
↓ jmp 8a
0.00 2.00 68: decl __abort_msg@@GLIBC_PRIVATE+0x8a0
21.56 2.00 1 ↓ je 8a
70: lea __abort_msg@@GLIBC_PRIVATE+0x8a0,%rdi
sub $0x80,%rsp
→ callq __lll_unlock_wake_private
add $0x80,%rsp
21.56 2.90 8a: movslq 0xc(%rsp),%rax
2.90 add $0x18,%rsp
9.03 2.90 1 ← retq

It shows for this symbol the average IPC is 2.30 and the IPC coverage
is 54.8%.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
tools/perf/util/annotate.c | 41 ++++++++++++++++++++++++++++++++++++++---
tools/perf/util/annotate.h | 5 +++++
2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 6936daf..4b2b1b0 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1000,6 +1000,7 @@ static unsigned annotation__count_insn(struct annotation *notes, u64 start, u64
static void annotation__count_and_fill(struct annotation *notes, u64 start, u64 end, struct cyc_hist *ch)
{
unsigned n_insn;
+ unsigned int cover_insn = 0;
u64 offset;

n_insn = annotation__count_insn(notes, start, end);
@@ -1013,21 +1014,34 @@ static void annotation__count_and_fill(struct annotation *notes, u64 start, u64
for (offset = start; offset <= end; offset++) {
struct annotation_line *al = notes->offsets[offset];

- if (al)
+ if (al && al->ipc == 0.0) {
al->ipc = ipc;
+ cover_insn++;
+ }
+ }
+
+ if (cover_insn) {
+ notes->hit_cycles += ch->cycles;
+ notes->hit_insn += n_insn * ch->num;
+ notes->cover_insn += cover_insn;
}
}
}

void annotation__compute_ipc(struct annotation *notes, size_t size)
{
- u64 offset;
+ s64 offset;

if (!notes->src || !notes->src->cycles_hist)
return;

+ notes->total_insn = annotation__count_insn(notes, 0, size - 1);
+ notes->hit_cycles = 0;
+ notes->hit_insn = 0;
+ notes->cover_insn = 0;
+
pthread_mutex_lock(&notes->lock);
- for (offset = 0; offset < size; ++offset) {
+ for (offset = size - 1; offset >= 0; --offset) {
struct cyc_hist *ch;

ch = &notes->src->cycles_hist[offset];
@@ -2563,6 +2577,22 @@ static void disasm_line__write(struct disasm_line *dl, struct annotation *notes,
disasm_line__scnprintf(dl, bf, size, !notes->options->use_offset);
}

+static void ipc_coverage_string(char *bf, int size, struct annotation *notes)
+{
+ double ipc = 0.0, coverage = 0.0;
+
+ if (notes->hit_cycles)
+ ipc = notes->hit_insn / ((double)notes->hit_cycles);
+
+ if (notes->total_insn) {
+ coverage = notes->cover_insn * 100.0 /
+ ((double)notes->total_insn);
+ }
+
+ scnprintf(bf, size, "(Average IPC: %.2f, IPC Coverage: %.1f%%)",
+ ipc, coverage);
+}
+
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,
@@ -2658,6 +2688,11 @@ static void __annotation_line__write(struct annotation_line *al, struct annotati
ANNOTATION__MINMAX_CYCLES_WIDTH - 1,
"Cycle(min/max)");
}
+
+ if (show_title && !*al->line) {
+ ipc_coverage_string(bf, sizeof(bf), notes);
+ obj__printf(obj, "%*s", ANNOTATION__AVG_IPC_WIDTH, bf);
+ }
}

obj__printf(obj, " ");
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index 5399ba2..fb64637 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -64,6 +64,7 @@ bool ins__is_fused(struct arch *arch, const char *ins1, const char *ins2);
#define ANNOTATION__IPC_WIDTH 6
#define ANNOTATION__CYCLES_WIDTH 6
#define ANNOTATION__MINMAX_CYCLES_WIDTH 19
+#define ANNOTATION__AVG_IPC_WIDTH 36

struct annotation_options {
bool hide_src_code,
@@ -262,6 +263,10 @@ struct annotation {
pthread_mutex_t lock;
u64 max_coverage;
u64 start;
+ u64 hit_cycles;
+ u64 hit_insn;
+ unsigned int total_insn;
+ unsigned int cover_insn;
struct annotation_options *options;
struct annotation_line **offsets;
int nr_events;
--
2.7.4