perf report/annotate: Support average IPC and IPC coverage for function

Add supporting of displaying the average IPC and IPC coverage percentage per function.

For example,

$ perf record -g -b ...
$ perf report -s symbol,ipc or
  perf report -s symbol,ipc --stdio

Overhead  Symbol                           IPC   [IPC Coverage]
  39.60%  [.] __random                     2.30  [ 54.8%]
  18.02%  [.] main                         0.43  [ 54.3%]
  14.21%  [.] compute_flag                 2.29  [100.0%]
  14.16%  [.] rand                         0.36  [100.0%]
   7.06%  [.] __random_r                   2.57  [ 70.5%]
   6.85%  [.] rand@plt                     0.00  [  0.0%]

...

$ 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
...

v2:
---
1. Merge in Jiri's patch to support stdio mode

2. Add a new patch "perf annotate: Create a annotate2 flag in struct symbol" which records if the symbol has been annotated yet.

3. Minor update such as adding { } for multiline code in 'if' condition.

Jin Yao (3):
perf annotate: Compute average IPC and IPC coverage per symbol perf annotate: Create a annotate2 flag in struct symbol perf report: Display average IPC and IPC coverage per symbol

 tools/perf/Documentation/perf-report.txt |  1 +
 tools/perf/builtin-report.c              | 14 ++++++++---
 tools/perf/util/annotate.c               | 42 +++++++++++++++++++++++++++++---
 tools/perf/util/annotate.h               |  5 ++++
 tools/perf/util/hist.h                   |  1 +
 tools/perf/util/sort.c                   | 42 ++++++++++++++++++++++++++++++++
 tools/perf/util/sort.h                   |  1 +
 tools/perf/util/symbol.h                 |  1 +
 8 files changed, 101 insertions(+), 6 deletions(-)

2.7.4

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%.

---
 tools/perf/util/annotate.c | 41 ++++++++++++++++++++++++++++++++++++++---
 tools/perf/util/annotate.h |  5 +++++
 2 files changed, 43 insertions(+), 3 deletions(-)

index 6936daf..4b2b1b0 100644
@@ -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, " ");

index 5399ba2..fb64637 100644
@@ -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

We often use the symbol__annotate2() to annotate a specified symbol. While annotating may take some time, so in order to avoid annotating the same symbol repeatedly, the patch creates a new flag to indicate the symbol has been annotated.

---
 tools/perf/util/annotate.c | 1 +
 tools/perf/util/symbol.h   | 1 +
 2 files changed, 2 insertions(+)

index 4b2b1b0..f69d8e1 100644
@@ -2798,6 +2798,7 @@ int symbol__annotate2(struct symbol *sym, struct map *map, struct perf_evsel *ev
 	notes->nr_events = nr_pcnt;
 
 	annotation__update_column_widths(notes);
+	sym->annotate2 = true;
 
 	return 0;
 

index d026d21..14d9d43 100644
@@ -63,6 +63,7 @@ struct symbol {
 	u8		ignore:1;
 	u8		inlined:1;
 	u8		arch_sym;
+	bool		annotate2;
 	char		name[0];
 };
 

2.7.4

Support displaying the average IPC and IPC coverage for symbol in perf report TUI browser. We create a new sort-key 'ipc' for that.

For example,

$ perf record -g -b ...
$ perf report -s symbol,ipc or
  perf report -s ipc

Overhead  Symbol                           IPC   [IPC Coverage]
  39.60%  [.] __random                     2.30  [ 54.8%]
  18.02%  [.] main                         0.43  [ 54.3%]
  14.21%  [.] compute_flag                 2.29  [100.0%]
  14.16%  [.] rand                         0.36  [100.0%]
   7.06%  [.] __random_r                   2.57  [ 70.5%]
   6.85%  [.] rand@plt                     0.00  [  0.0%]

Jiri Olsa <[email protected]> provided the patch to support the stdio mode. I merged Jiri's code in this patch.

$ perf report -s ipc --stdio

  # Overhead  Symbol                       IPC   [IPC Coverage]
  # ........  ...........................  ....................
  #
    39.60%  [.] __random                   2.30  [ 54.8%]
    18.02%  [.] main                       0.43  [ 54.3%]
    14.21%  [.] compute_flag               2.29  [100.0%]
    14.16%  [.] rand                       0.36  [100.0%]
     7.06%  [.] __random_r                 2.57  [ 70.5%]
     6.85%  [.] rand@plt                   0.00  [  0.0%]
     0.02%  [k] run_timer_softirq          1.60  [ 57.2%]

v2:
---
Merge in Jiri's patch to support stdio mode

---
 tools/perf/Documentation/perf-report.txt |  1 +
 tools/perf/builtin-report.c              | 14 ++++++++---
 tools/perf/util/hist.h                   |  1 +
 tools/perf/util/sort.c                   | 42 ++++++++++++++++++++++++++++++++
 tools/perf/util/sort.h                   |  1 +
 5 files changed, 56 insertions(+), 3 deletions(-)

index 474a494..e7b8974 100644
@@ -122,6 +122,7 @@ OPTIONS
 	- in_tx: branch in TSX transaction
 	- abort: TSX transaction abort.
 	- cycles: Cycles in basic block
+	- ipc: average ipc (instruction per cycle) of function
 
 	And default sort keys are changed to comm, dso_from, symbol_from, dso_to
 	and symbol_to, see '--branch-stack'.

index 257c9c1..a6756dc 100644
@@ -85,6 +85,7 @@ struct report {
 	int			socket_filter;
 	DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
 	struct branch_type_stat	brtype_stat;
+	bool			symbol_ipc;
 };
 
 static int report__config(const char *var, const char *value, void *cb)

@@ -129,7 +130,7 @@ static int hist_iter__report_callback(struct hist_entry_iter *iter,
 	struct mem_info *mi;
 	struct branch_info *bi;
 
-	if (!ui__has_annotation())
+	if (!ui__has_annotation() && !rep->symbol_ipc)
 		return 0;
 
 	hist__account_cycles(sample->branch_stack, al, sample,

@@ -174,7 +175,7 @@ static int hist_iter__branch_callback(struct hist_entry_iter *iter,
 	struct perf_evsel *evsel = iter->evsel;
 	int err;
 
-	if (!ui__has_annotation())
+	if (!ui__has_annotation() && !rep->symbol_ipc)
 		return 0;
 
 	hist__account_cycles(sample->branch_stack, al, sample,

@@ -1284,6 +1285,13 @@ int cmd_report(int argc, const char **argv)
 	else
 		use_browser = 0;
 
+	if ((sort__mode == SORT_MODE__BRANCH) && sort_order &&
+		strstr(sort_order, "ipc")) {
+		if (!strstr(sort_order, "symbol"))
+			sort_order = "symbol,ipc";
+		report.symbol_ipc = true;
+	}
+
 	if (setup_sorting(session->evlist) < 0) {
 		if (sort_order)
 			parse_options_usage(report_usage, options, "s", 1);

@@ -1311,7 +1319,7 @@ int cmd_report(int argc, const char **argv)
 	 * so don't allocate extra space that won't be used in the stdio
 	 * implementation.
 	 */
-	if (ui__has_annotation()) {
+	if (ui__has_annotation() || report.symbol_ipc) {
 		ret = symbol__annotation_init();
 		if (ret < 0)
 			goto error;

index 3badd7f..664b5ed 100644
@@ -62,6 +62,7 @@ enum hist_column {
 	HISTC_TRACE,
 	HISTC_SYM_SIZE,
 	HISTC_DSO_SIZE,
+	HISTC_SYMBOL_IPC,
 	HISTC_NR_COLS, /* Last entry */
 };
 

index a97cf8e..de70736 100644
@@ -242,6 +242,7 @@ enum sort_type {
 	SORT_CYCLES,
 	SORT_SRCLINE_FROM,
 	SORT_SRCLINE_TO,
+	SORT_SYM_IPC,
 
 	/* memory mode specific sort keys */
 	__SORT_MEMORY_MODE,

2.7.4

Another thing that would be nice would be to automatically enable these columns perf report when -b was enabled in the perf.data. We can't check for timed LBR being supported without looking into samples, but at least can check for -b.

Otherwise a lot of people won't realize it's supported.

It would show always 0.0 when timed LBR is not supported, but that might be ok. Perhaps make both columns empty in this case instead of 0.0.

-Andi

Hi Andi,

Yes, I agree, people will not realize a new option 'ipc' is created.

So I will enable 2 columns ("IPC" and "IPC columns") even when timed LBR is not supported. Just show empty or '-' in these columns.

Thanks
Jin Yao