[PATCH v3 0/7] perf diff: diff cycles at basic block level

[PATCH v3 0/7] perf diff: diff cycles at basic block level

[Jin Yao]

In some cases small changes in hot loops can show big differences.
But it's difficult to identify these differences.

perf diff currently can only diff symbols (functions). We can also expand
it to diff cycles of individual programs blocks as reported by timed LBR.
This would allow to identify changes in specific code accurately.

With this patch set, for example,

 # perf record -b ./div
 # perf record -b ./div
 # perf diff -c cycles

 # Event 'cycles'
 #
 # Baseline         Block cycles diff [start:end]  Shared Object     Symbol
 # ........  ....................................  ................  ....................................
 #
     49.03%        -9 [         4ef:         520]  div               [.] main
     49.03%         0 [         4e8:         4ea]  div               [.] main
     49.03%         0 [         4ef:         500]  div               [.] main
     49.03%         0 [         4ef:         51c]  div               [.] main
     49.03%         0 [         4ef:         535]  div               [.] main
     18.82%         0 [       3ac40:       3ac4d]  libc-2.23.so      [.] __random_r
     18.82%         0 [       3ac40:       3ac5c]  libc-2.23.so      [.] __random_r
     18.82%         0 [       3ac40:       3ac76]  libc-2.23.so      [.] __random_r
     18.82%         0 [       3ac40:       3ac88]  libc-2.23.so      [.] __random_r
     18.82%         0 [       3ac90:       3ac9c]  libc-2.23.so      [.] __random_r
     16.29%        -8 [       3aac0:       3aac0]  libc-2.23.so      [.] __random
     16.29%         0 [       3aac0:       3aad2]  libc-2.23.so      [.] __random
     16.29%         0 [       3aae0:       3aae7]  libc-2.23.so      [.] __random
     16.29%         0 [       3ab03:       3ab0f]  libc-2.23.so      [.] __random
     16.29%         0 [       3ab14:       3ab1b]  libc-2.23.so      [.] __random
     16.29%         0 [       3ab28:       3ab2e]  libc-2.23.so      [.] __random
     16.29%         0 [       3ab4a:       3ab53]  libc-2.23.so      [.] __random
      8.11%         0 [         640:         644]  div               [.] compute_flag
      8.11%         0 [         649:         659]  div               [.] compute_flag
      5.46%         0 [       3af60:       3af60]  libc-2.23.so      [.] rand
      5.46%         0 [       3af60:       3af64]  libc-2.23.so      [.] rand
      2.25%         0 [         490:         490]  div               [.] rand@plt
      0.01%        26 [      c00a27:      c00a27]  [kernel.vmlinux]  [k] native_irq_return_iret
      0.00%      -157 [      2bf9f2:      2bfa63]  [kernel.vmlinux]  [k] update_blocked_averages
      0.00%       -56 [      2bf980:      2bf9d3]  [kernel.vmlinux]  [k] update_blocked_averages
      0.00%        48 [      2bf934:      2bf942]  [kernel.vmlinux]  [k] update_blocked_averages
      0.00%         3 [      2bfb38:      2bfb67]  [kernel.vmlinux]  [k] update_blocked_averages

The 'cycles' is a new perf-diff computation selection, which enables
the displaying of cycles difference of same program basic block amongst
two perf.data. The program basic block is the code block between two
branches in a function.

 v3:
 ---
 In v3, the major change is to move most of block stuffs from
 'struct hist_entry' to new structure 'struct block_hist' and
 update the code accordingly. But we still have to keep the 
 block_info in 'struct hist_entry' since we need to compare by 
 block info when inserting new entry to hists.

 Others are minor changes, such as abs() -> labs(), removing
 duplicated ops and etc.

 Changed patches:
  perf diff: Use hists to manage basic blocks per symbol
  perf diff: Link same basic blocks among different data
  perf diff: Print the basic block cycles diff

 v2:
 ---
 Keep standard perf diff format.

 Following is the v1 output.

 # perf diff --basic-block

 # Cycles diff  Basic block (start:end)
 # ...........  .......................
 #
          -208  hrtimer_interrupt (30b9e0:30ba42)
          -157  update_blocked_averages (2bf9f2:2bfa63)
          -126  interrupt_entry (c00880:c0093a)
           -86  hrtimer_interrupt (30bb29:30bb32)
           -74  hrtimer_interrupt (30ba65:30bac4)
           -56  update_blocked_averages (2bf980:2bf9d3)
            48  update_blocked_averages (2bf934:2bf942)
           -35  native_write_msr (267900:26790b)
            26  native_irq_return_iret (c00a27:c00a27)
            22  rcu_check_callbacks (2febb6:2febdc)
           -21  __hrtimer_run_queues (30b220:30b2a3)
            19  pvclock_gtod_notify (14ba0:14c1b)
           -18  task_tick_fair (2c5d29:2c5d41)

Jin Yao (7):
  perf util: Create block_info structure
  perf util: Add block_info in hist_entry
  perf diff: Check if all data files with branch stacks
  perf diff: Use hists to manage basic blocks per symbol
  perf diff: Link same basic blocks among different data
  perf diff: Print the basic block cycles diff
  perf diff: Documentation -c cycles option

 tools/perf/Documentation/perf-diff.txt |  14 +-
 tools/perf/builtin-diff.c              | 383 ++++++++++++++++++++++++++++++++-
 tools/perf/ui/stdio/hist.c             |  27 +++
 tools/perf/util/hist.c                 |  40 +++-
 tools/perf/util/hist.h                 |   9 +
 tools/perf/util/sort.h                 |  13 ++
 tools/perf/util/symbol.c               |  22 ++
 tools/perf/util/symbol.h               |  23 ++
 tools/perf/util/symbol_conf.h          |   1 +
 9 files changed, 522 insertions(+), 10 deletions(-)

-- 
2.7.4

[PATCH v3 1/7] perf util: Create block_info structure

[Jin Yao]

perf diff currently can only diff symbols(functions). We should expand it
to diff cycles of individual programs blocks as reported by timed LBR.
This would allow to identify changes in specific code accurately.

We need a new structure to maintain the basic block information, such as,
symbol(function), start/end address of this block, cycles. This patch
creates this structure and with some ops.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/util/symbol.c | 22 ++++++++++++++++++++++
 tools/perf/util/symbol.h | 23 +++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index f4540f8..4e0a7b3 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -2351,3 +2351,25 @@ struct mem_info *mem_info__new(void)
 		refcount_set(&mi->refcnt, 1);
 	return mi;
 }
+
+struct block_info *block_info__get(struct block_info *bi)
+{
+	if (bi)
+		refcount_inc(&bi->refcnt);
+	return bi;
+}
+
+void block_info__put(struct block_info *bi)
+{
+	if (bi && refcount_dec_and_test(&bi->refcnt))
+		free(bi);
+}
+
+struct block_info *block_info__new(void)
+{
+	struct block_info *bi = zalloc(sizeof(*bi));
+
+	if (bi)
+		refcount_set(&bi->refcnt, 1);
+	return bi;
+}
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 9a8fe01..12755b4 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -131,6 +131,17 @@ struct mem_info {
 	refcount_t		refcnt;
 };
 
+struct block_info {
+	struct symbol		*sym;
+	u64			start;
+	u64			end;
+	u64			cycles;
+	u64			cycles_aggr;
+	int			num;
+	int			num_aggr;
+	refcount_t		refcnt;
+};
+
 struct addr_location {
 	struct machine *machine;
 	struct thread *thread;
@@ -332,4 +343,16 @@ static inline void __mem_info__zput(struct mem_info **mi)
 
 #define mem_info__zput(mi) __mem_info__zput(&mi)
 
+struct block_info *block_info__new(void);
+struct block_info *block_info__get(struct block_info *bi);
+void   block_info__put(struct block_info *bi);
+
+static inline void __block_info__zput(struct block_info **bi)
+{
+	block_info__put(*bi);
+	*bi = NULL;
+}
+
+#define block_info__zput(bi) __block_info__zput(&bi)
+
 #endif /* __PERF_SYMBOL */
-- 
2.7.4

[PATCH v3 2/7] perf util: Add block_info in hist_entry

[Jin Yao]

The block_info contains the program basic block information, i.e,
contains the start address and the end address of this basic block and
how much cycles it takes. We need to compare, sort and even print out
the basic block by some orders, i.e. sort by cycles.

For this purpose, we add block_info field to hist_entry. In order not to
impact current interface, we creates a new function hists__add_entry_block.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/util/hist.c | 22 ++++++++++++++++++++--
 tools/perf/util/hist.h |  6 ++++++
 tools/perf/util/sort.h |  1 +
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index fb3271f..680ad93 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -574,6 +574,8 @@ static struct hist_entry *hists__findnew_entry(struct hists *hists,
 			 */
 			mem_info__zput(entry->mem_info);
 
+			block_info__zput(entry->block_info);
+
 			/* If the map of an existing hist_entry has
 			 * become out-of-date due to an exec() or
 			 * similar, update it.  Otherwise we will
@@ -645,6 +647,7 @@ __hists__add_entry(struct hists *hists,
 		   struct symbol *sym_parent,
 		   struct branch_info *bi,
 		   struct mem_info *mi,
+		   struct block_info *block_info,
 		   struct perf_sample *sample,
 		   bool sample_self,
 		   struct hist_entry_ops *ops)
@@ -677,6 +680,7 @@ __hists__add_entry(struct hists *hists,
 		.hists	= hists,
 		.branch_info = bi,
 		.mem_info = mi,
+		.block_info = block_info,
 		.transaction = sample->transaction,
 		.raw_data = sample->raw_data,
 		.raw_size = sample->raw_size,
@@ -699,7 +703,7 @@ struct hist_entry *hists__add_entry(struct hists *hists,
 				    struct perf_sample *sample,
 				    bool sample_self)
 {
-	return __hists__add_entry(hists, al, sym_parent, bi, mi,
+	return __hists__add_entry(hists, al, sym_parent, bi, mi, NULL,
 				  sample, sample_self, NULL);
 }
 
@@ -712,10 +716,24 @@ struct hist_entry *hists__add_entry_ops(struct hists *hists,
 					struct perf_sample *sample,
 					bool sample_self)
 {
-	return __hists__add_entry(hists, al, sym_parent, bi, mi,
+	return __hists__add_entry(hists, al, sym_parent, bi, mi, NULL,
 				  sample, sample_self, ops);
 }
 
+struct hist_entry *hists__add_entry_block(struct hists *hists,
+					  struct hist_entry_ops *ops,
+					  struct addr_location *al,
+					  struct block_info *block_info)
+{
+	struct hist_entry entry = {
+		.ops = ops,
+		.block_info = block_info,
+		.hists = hists,
+	}, *he = hists__findnew_entry(hists, &entry, al, false);
+
+	return he;
+}
+
 static int
 iter_next_nop_entry(struct hist_entry_iter *iter __maybe_unused,
 		    struct addr_location *al __maybe_unused)
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index 76ff6c6..c8f7d66 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -16,6 +16,7 @@ struct addr_location;
 struct map_symbol;
 struct mem_info;
 struct branch_info;
+struct block_info;
 struct symbol;
 
 enum hist_filter {
@@ -149,6 +150,11 @@ struct hist_entry *hists__add_entry_ops(struct hists *hists,
 					struct perf_sample *sample,
 					bool sample_self);
 
+struct hist_entry *hists__add_entry_block(struct hists *hists,
+					  struct hist_entry_ops *ops,
+					  struct addr_location *al,
+					  struct block_info *bi);
+
 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
 			 int max_stack_depth, void *arg);
 
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index ce376a7..43623fa 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -144,6 +144,7 @@ struct hist_entry {
 	long			time;
 	struct hists		*hists;
 	struct mem_info		*mem_info;
+	struct block_info	*block_info;
 	void			*raw_data;
 	u32			raw_size;
 	int			num_res;
-- 
2.7.4

[PATCH v3 3/7] perf diff: Check if all data files with branch stacks

[Jin Yao]

We will expand perf diff to support diff cycles of individual programs
blocks, so it requires all data files having branch stacks.

This patch checks HEADER_BRANCH_STACK in header, and only set the flag
has_br_stack when HEADER_BRANCH_STACK are set in all data files.

 v2:
 ---
 Move check_file_brstack() from __cmd_diff() to cmd_diff().
 Because later patch will check flag 'has_br_stack' before
 ui_init().

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/builtin-diff.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 6e79207..a7e0420 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -32,6 +32,7 @@ struct perf_diff {
 	struct perf_time_interval	*ptime_range;
 	int				 range_size;
 	int				 range_num;
+	bool				 has_br_stack;
 };
 
 /* Diff command specific HPP columns. */
@@ -873,6 +874,31 @@ static int parse_time_str(struct data__file *d, char *abstime_ostr,
 	return ret;
 }
 
+static int check_file_brstack(void)
+{
+	struct data__file *d;
+	bool has_br_stack;
+	int i;
+
+	data__for_each_file(i, d) {
+		d->session = perf_session__new(&d->data, false, &pdiff.tool);
+		if (!d->session) {
+			pr_err("Failed to open %s\n", d->data.path);
+			return -1;
+		}
+
+		has_br_stack = perf_header__has_feat(&d->session->header,
+						     HEADER_BRANCH_STACK);
+		perf_session__delete(d->session);
+		if (!has_br_stack)
+			return 0;
+	}
+
+	/* Set only all files having branch stacks */
+	pdiff.has_br_stack = true;
+	return 0;
+}
+
 static int __cmd_diff(void)
 {
 	struct data__file *d;
@@ -1487,6 +1513,9 @@ int cmd_diff(int argc, const char **argv)
 	if (data_init(argc, argv) < 0)
 		return -1;
 
+	if (check_file_brstack() < 0)
+		return -1;
+
 	if (ui_init() < 0)
 		return -1;
 
-- 
2.7.4

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

[Jin Yao]

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@linux.intel.com>
---
 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

[PATCH v3 5/7] perf diff: Link same basic blocks among different data

[Jin Yao]

The target is to compare the performance difference (cycles
diff) for the same basic blocks in different data files.

The same basic block means same function, same start address
and same end address. This patch finds the same basic blocks
from different data files and link them together and resort
by the cycles diff.

 v3:
 ---
 The block stuffs are maintained by new structure 'block_hist',
 so this patch is update accordingly.

 v2:
 ---
 Since now the basic block hists is changed to per symbol,
 the patch only links the basic block hists for the same
 symbol in different data files.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/builtin-diff.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index c6ec84d..5f5a9a9 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -660,6 +660,85 @@ static int process_block_per_sym(struct hist_entry *he)
 	return 0;
 }
 
+static int block_pair_cmp(struct hist_entry *a, struct hist_entry *b)
+{
+	struct block_info *bi_a = a->block_info;
+	struct block_info *bi_b = b->block_info;
+	int cmp;
+
+	if (!bi_a->sym || !bi_b->sym)
+		return -1;
+
+	if (bi_a->sym->name && bi_b->sym->name) {
+		cmp = strcmp(bi_a->sym->name, bi_b->sym->name);
+		if ((!cmp) && (bi_a->start == bi_b->start) &&
+		    (bi_a->end == bi_b->end)) {
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+static struct hist_entry *get_block_pair(struct hist_entry *he,
+					 struct hists *hists_pair)
+{
+	struct rb_root_cached *root = hists_pair->entries_in;
+	struct rb_node *next = rb_first_cached(root);
+	int cmp;
+
+	while (next != NULL) {
+		struct hist_entry *he_pair = rb_entry(next, struct hist_entry,
+						      rb_node_in);
+
+		next = rb_next(&he_pair->rb_node_in);
+
+		cmp = block_pair_cmp(he_pair, he);
+		if (!cmp)
+			return he_pair;
+	}
+
+	return NULL;
+}
+
+static void compute_cycles_diff(struct hist_entry *he,
+				struct hist_entry *pair)
+{
+	pair->diff.computed = true;
+	if (pair->block_info->num && he->block_info->num) {
+		pair->diff.cycles =
+			pair->block_info->cycles_aggr / pair->block_info->num_aggr -
+			he->block_info->cycles_aggr / he->block_info->num_aggr;
+	}
+}
+
+static void block_hists_match(struct hists *hists_base,
+			      struct hists *hists_pair)
+{
+	struct rb_root_cached *root = hists_base->entries_in;
+	struct rb_node *next = rb_first_cached(root);
+
+	while (next != NULL) {
+		struct hist_entry *he = rb_entry(next, struct hist_entry,
+						 rb_node_in);
+		struct hist_entry *pair = get_block_pair(he, hists_pair);
+
+		next = rb_next(&he->rb_node_in);
+
+		if (pair) {
+			hist_entry__add_pair(pair, he);
+			compute_cycles_diff(he, pair);
+		}
+	}
+}
+
+static int filter_cb(struct hist_entry *he, void *arg __maybe_unused)
+{
+	/* Skip the calculation of column length in output_resort */
+	he->filtered = true;
+	return 0;
+}
+
 static void hists__precompute(struct hists *hists)
 {
 	struct rb_root_cached *root;
@@ -672,6 +751,7 @@ static void hists__precompute(struct hists *hists)
 
 	next = rb_first_cached(root);
 	while (next != NULL) {
+		struct block_hist *bh, *pair_bh;
 		struct hist_entry *he, *pair;
 		struct data__file *d;
 		int i;
@@ -700,6 +780,16 @@ static void hists__precompute(struct hists *hists)
 				break;
 			case COMPUTE_CYCLES:
 				process_block_per_sym(pair);
+				bh = container_of(he, struct block_hist, he);
+				pair_bh = container_of(pair, struct block_hist,
+						       he);
+
+				if (bh->valid && pair_bh->valid) {
+					block_hists_match(&bh->block_hists,
+							  &pair_bh->block_hists);
+					hists__output_resort_cb(&pair_bh->block_hists,
+								NULL, filter_cb);
+				}
 				break;
 			default:
 				BUG_ON(1);
-- 
2.7.4

[PATCH v3 6/7] perf diff: Print the basic block cycles diff

[Jin Yao]

perf record -b ./div
perf record -b ./div

Following is the default perf diff output

 # perf diff

 # Event 'cycles'
 #
 # Baseline  Delta Abs  Shared Object     Symbol
 # ........  .........  ................  ....................................
 #
     49.03%     +0.30%  div               [.] main
     16.29%     -0.20%  libc-2.23.so      [.] __random
     18.82%     -0.07%  libc-2.23.so      [.] __random_r
      8.11%     -0.04%  div               [.] compute_flag
      2.25%     +0.01%  div               [.] rand@plt
      0.00%     +0.01%  [kernel.vmlinux]  [k] task_tick_fair
      5.46%     +0.01%  libc-2.23.so      [.] rand
      0.01%     -0.01%  [kernel.vmlinux]  [k] native_irq_return_iret
      0.00%     -0.00%  [kernel.vmlinux]  [k] interrupt_entry

This patch creates a new computation selection 'cycles'.

 # perf diff -c cycles

 # Event 'cycles'
 #
 # Baseline         Block cycles diff [start:end]  Shared Object     Symbol
 # ........  ....................................  ................  ....................................
 #
     49.03%        -9 [         4ef:         520]  div               [.] main
     49.03%         0 [         4e8:         4ea]  div               [.] main
     49.03%         0 [         4ef:         500]  div               [.] main
     49.03%         0 [         4ef:         51c]  div               [.] main
     49.03%         0 [         4ef:         535]  div               [.] main
     18.82%         0 [       3ac40:       3ac4d]  libc-2.23.so      [.] __random_r
     18.82%         0 [       3ac40:       3ac5c]  libc-2.23.so      [.] __random_r
     18.82%         0 [       3ac40:       3ac76]  libc-2.23.so      [.] __random_r
     18.82%         0 [       3ac40:       3ac88]  libc-2.23.so      [.] __random_r
     18.82%         0 [       3ac90:       3ac9c]  libc-2.23.so      [.] __random_r
     16.29%        -8 [       3aac0:       3aac0]  libc-2.23.so      [.] __random
     16.29%         0 [       3aac0:       3aad2]  libc-2.23.so      [.] __random
     16.29%         0 [       3aae0:       3aae7]  libc-2.23.so      [.] __random
     16.29%         0 [       3ab03:       3ab0f]  libc-2.23.so      [.] __random
     16.29%         0 [       3ab14:       3ab1b]  libc-2.23.so      [.] __random
     16.29%         0 [       3ab28:       3ab2e]  libc-2.23.so      [.] __random
     16.29%         0 [       3ab4a:       3ab53]  libc-2.23.so      [.] __random
      8.11%         0 [         640:         644]  div               [.] compute_flag
      8.11%         0 [         649:         659]  div               [.] compute_flag
      5.46%         0 [       3af60:       3af60]  libc-2.23.so      [.] rand
      5.46%         0 [       3af60:       3af64]  libc-2.23.so      [.] rand
      2.25%         0 [         490:         490]  div               [.] rand@plt
      0.01%        26 [      c00a27:      c00a27]  [kernel.vmlinux]  [k] native_irq_return_iret
      0.00%      -157 [      2bf9f2:      2bfa63]  [kernel.vmlinux]  [k] update_blocked_averages
      0.00%       -56 [      2bf980:      2bf9d3]  [kernel.vmlinux]  [k] update_blocked_averages
      0.00%        48 [      2bf934:      2bf942]  [kernel.vmlinux]  [k] update_blocked_averages
      0.00%         3 [      2bfb38:      2bfb67]  [kernel.vmlinux]  [k] update_blocked_averages
      0.00%         0 [      2bf968:      2bf97b]  [kernel.vmlinux]  [k] update_blocked_averages

"[start:end]" indicates the basic block range. The output is sorted
by "Baseline" and the basic blocks in the same function are sorted
by cycles diff.

 v3:
 ---
 Cast 'struct hist_entry' to 'struct block_hist' in hist_entry__block_fprintf.
 Use symbol_conf.report_block to check if executing hist_entry__block_fprintf.

 v2:
 ---
 Keep standard perf diff format and display the 'Baseline' and
 'Shared Object'.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/builtin-diff.c     | 59 ++++++++++++++++++++++++++++++++++++++++---
 tools/perf/ui/stdio/hist.c    | 27 ++++++++++++++++++++
 tools/perf/util/hist.c        | 18 +++++++++++++
 tools/perf/util/hist.h        |  3 +++
 tools/perf/util/symbol_conf.h |  1 +
 5 files changed, 104 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 5f5a9a9..a56d941 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -46,6 +46,7 @@ enum {
 	PERF_HPP_DIFF__WEIGHTED_DIFF,
 	PERF_HPP_DIFF__FORMULA,
 	PERF_HPP_DIFF__DELTA_ABS,
+	PERF_HPP_DIFF__CYCLES,
 
 	PERF_HPP_DIFF__MAX_INDEX
 };
@@ -114,6 +115,7 @@ static int compute_2_hpp[COMPUTE_MAX] = {
 	[COMPUTE_DELTA_ABS]	= PERF_HPP_DIFF__DELTA_ABS,
 	[COMPUTE_RATIO]		= PERF_HPP_DIFF__RATIO,
 	[COMPUTE_WEIGHTED_DIFF]	= PERF_HPP_DIFF__WEIGHTED_DIFF,
+	[COMPUTE_CYCLES]	= PERF_HPP_DIFF__CYCLES,
 };
 
 #define MAX_COL_WIDTH 70
@@ -152,6 +154,10 @@ static struct header_column {
 	[PERF_HPP_DIFF__FORMULA] = {
 		.name  = "Formula",
 		.width = MAX_COL_WIDTH,
+	},
+	[PERF_HPP_DIFF__CYCLES] = {
+		.name  = "Block cycles diff [start:end]",
+		.width = 36,
 	}
 };
 
@@ -239,8 +245,6 @@ 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);
 		}
 
@@ -1002,6 +1006,9 @@ static void hists__process(struct hists *hists)
 	hists__precompute(hists);
 	hists__output_resort(hists, NULL);
 
+	if (compute == COMPUTE_CYCLES)
+		symbol_conf.report_block = true;
+
 	hists__fprintf(hists, !quiet, 0, 0, 0, stdout,
 		       !symbol_conf.use_callchain);
 }
@@ -1257,7 +1264,7 @@ static const struct option options[] = {
 	OPT_BOOLEAN('b', "baseline-only", &show_baseline_only,
 		    "Show only items with match in baseline"),
 	OPT_CALLBACK('c', "compute", &compute,
-		     "delta,delta-abs,ratio,wdiff:w1,w2 (default delta-abs)",
+		     "delta,delta-abs,ratio,wdiff:w1,w2 (default delta-abs),cycles",
 		     "Entries differential computation selection",
 		     setup_compute),
 	OPT_BOOLEAN('p', "period", &show_period,
@@ -1335,6 +1342,29 @@ static int hpp__entry_baseline(struct hist_entry *he, char *buf, size_t size)
 	return ret;
 }
 
+static int cycles_printf(struct hist_entry *he, struct hist_entry *pair,
+			 struct perf_hpp *hpp, int width)
+{
+	struct block_hist *bh = container_of(he, struct block_hist, he);
+	struct block_hist *bh_pair = container_of(pair, struct block_hist, he);
+	struct hist_entry *block_he;
+	struct block_info *bi;
+	char buf[128];
+
+	block_he = hists__get_entry(&bh_pair->block_hists, bh->block_idx);
+	if (!block_he) {
+		hpp->skip = true;
+		return 0;
+	}
+
+	bi = block_he->block_info;
+	scnprintf(buf, sizeof(buf), "%ld [%12lx:%12lx]",
+		  block_he->diff.cycles, bi->sym->start + bi->start,
+		  bi->sym->start + bi->end);
+
+	return scnprintf(hpp->buf, hpp->size, "%*s", width, buf);
+}
+
 static int __hpp__color_compare(struct perf_hpp_fmt *fmt,
 				struct perf_hpp *hpp, struct hist_entry *he,
 				int comparison_method)
@@ -1346,8 +1376,17 @@ static int __hpp__color_compare(struct perf_hpp_fmt *fmt,
 	s64 wdiff;
 	char pfmt[20] = " ";
 
-	if (!pair)
+	if (!pair) {
+		if (comparison_method == COMPUTE_CYCLES) {
+			struct block_hist *bh;
+
+			bh = container_of(he, struct block_hist, he);
+			if (bh->block_idx)
+				hpp->skip = true;
+		}
+
 		goto no_print;
+	}
 
 	switch (comparison_method) {
 	case COMPUTE_DELTA:
@@ -1382,6 +1421,8 @@ static int __hpp__color_compare(struct perf_hpp_fmt *fmt,
 		return color_snprintf(hpp->buf, hpp->size,
 				get_percent_color(wdiff),
 				pfmt, wdiff);
+	case COMPUTE_CYCLES:
+		return cycles_printf(he, pair, hpp, dfmt->header_width);
 	default:
 		BUG_ON(1);
 	}
@@ -1411,6 +1452,12 @@ static int hpp__color_wdiff(struct perf_hpp_fmt *fmt,
 	return __hpp__color_compare(fmt, hpp, he, COMPUTE_WEIGHTED_DIFF);
 }
 
+static int hpp__color_cycles(struct perf_hpp_fmt *fmt,
+			     struct perf_hpp *hpp, struct hist_entry *he)
+{
+	return __hpp__color_compare(fmt, hpp, he, COMPUTE_CYCLES);
+}
+
 static void
 hpp__entry_unpair(struct hist_entry *he, int idx, char *buf, size_t size)
 {
@@ -1612,6 +1659,10 @@ static void data__hpp_register(struct data__file *d, int idx)
 		fmt->color = hpp__color_delta;
 		fmt->sort  = hist_entry__cmp_delta_abs;
 		break;
+	case PERF_HPP_DIFF__CYCLES:
+		fmt->color = hpp__color_cycles;
+		fmt->sort  = hist_entry__cmp_nop;
+		break;
 	default:
 		fmt->sort  = hist_entry__cmp_nop;
 		break;
diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c
index a60f299..4e74bb7 100644
--- a/tools/perf/ui/stdio/hist.c
+++ b/tools/perf/ui/stdio/hist.c
@@ -531,6 +531,30 @@ static int hist_entry__hierarchy_fprintf(struct hist_entry *he,
 	return printed;
 }
 
+static int hist_entry__block_fprintf(struct hist_entry *he,
+				     char *bf, size_t size,
+				     FILE *fp)
+{
+	struct block_hist *bh = container_of(he, struct block_hist, he);
+	int ret = 0;
+
+	for (unsigned int i = 0; i < bh->block_hists.nr_entries; i++) {
+		struct perf_hpp hpp = {
+			.buf		= bf,
+			.size		= size,
+			.skip		= false,
+		};
+
+		bh->block_idx = i;
+		hist_entry__snprintf(he, &hpp);
+
+		if (!hpp.skip)
+			ret += fprintf(fp, "%s\n", bf);
+	}
+
+	return ret;
+}
+
 static int hist_entry__fprintf(struct hist_entry *he, size_t size,
 			       char *bf, size_t bfsz, FILE *fp,
 			       bool ignore_callchains)
@@ -550,6 +574,9 @@ static int hist_entry__fprintf(struct hist_entry *he, size_t size,
 	if (symbol_conf.report_hierarchy)
 		return hist_entry__hierarchy_fprintf(he, &hpp, hists, fp);
 
+	if (symbol_conf.report_block)
+		return hist_entry__block_fprintf(he, bf, size, fp);
+
 	hist_entry__snprintf(he, &hpp);
 
 	ret = fprintf(fp, "%s\n", bf);
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 680ad93..2fb9cb2 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -376,6 +376,24 @@ void hists__delete_entries(struct hists *hists)
 	}
 }
 
+struct hist_entry *hists__get_entry(struct hists *hists, int idx)
+{
+	struct rb_node *next = rb_first_cached(&hists->entries);
+	struct hist_entry *n;
+	int i = 0;
+
+	while (next) {
+		n = rb_entry(next, struct hist_entry, rb_node);
+		if (i == idx)
+			return n;
+
+		next = rb_next(&n->rb_node);
+		i++;
+	}
+
+	return NULL;
+}
+
 /*
  * histogram, sorted on item, collects periods
  */
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index c8f7d66..9124b54 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -184,6 +184,8 @@ void hists__decay_entries(struct hists *hists, bool zap_user, bool zap_kernel);
 void hists__delete_entries(struct hists *hists);
 void hists__output_recalc_col_len(struct hists *hists, int max_rows);
 
+struct hist_entry *hists__get_entry(struct hists *hists, int idx);
+
 u64 hists__total_period(struct hists *hists);
 void hists__reset_stats(struct hists *hists);
 void hists__inc_stats(struct hists *hists, struct hist_entry *h);
@@ -249,6 +251,7 @@ struct perf_hpp {
 	size_t size;
 	const char *sep;
 	void *ptr;
+	bool skip;
 };
 
 struct perf_hpp_fmt {
diff --git a/tools/perf/util/symbol_conf.h b/tools/perf/util/symbol_conf.h
index 382ba63..be4b244 100644
--- a/tools/perf/util/symbol_conf.h
+++ b/tools/perf/util/symbol_conf.h
@@ -39,6 +39,7 @@ struct symbol_conf {
 			hide_unresolved,
 			raw_trace,
 			report_hierarchy,
+			report_block,
 			inline_name;
 	const char	*vmlinux_name,
 			*kallsyms_name,
-- 
2.7.4

[PATCH v3 7/7] perf diff: Documentation -c cycles option

[Jin Yao]

Documentation the new computation selection 'cycles'.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/Documentation/perf-diff.txt | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Documentation/perf-diff.txt b/tools/perf/Documentation/perf-diff.txt
index facd91e..73903d2 100644
--- a/tools/perf/Documentation/perf-diff.txt
+++ b/tools/perf/Documentation/perf-diff.txt
@@ -90,9 +90,10 @@ OPTIONS
 
 -c::
 --compute::
-        Differential computation selection - delta, ratio, wdiff, delta-abs
-        (default is delta-abs).  Default can be changed using diff.compute
-        config option.  See COMPARISON METHODS section for more info.
+        Differential computation selection - delta, ratio, wdiff, cycles,
+        delta-abs (default is delta-abs).  Default can be changed using
+        diff.compute config option.  See COMPARISON METHODS section for
+        more info.
 
 -p::
 --period::
@@ -280,6 +281,13 @@ If specified the 'Weighted diff' column is displayed with value 'd' computed as:
     - WEIGHT-A being the weight of the data file
     - WEIGHT-B being the weight of the baseline data file
 
+cycles
+~~~~~~
+If specified the 'Block cycles diff [start:end]' column is displayed.
+It displays the cycles difference of same program basic block amongst
+two perf.data. The program basic block is the code block between
+two branches in a function (indicated by [start:end]).
+
 SEE ALSO
 --------
 linkperf:perf-record[1], linkperf:perf-report[1]
-- 
2.7.4