[PATCH V4 3/3] perf tool: Add sort key symoff for perf diff

[kan.liang@intel.com]

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

Sometime, especially debugging scaling issue, the function level diff
may be high granularity. The user may want to do deeper diff analysis
for some cache or lock issue. The "symoff" key can let the user sort
differential profile by ips. This feature should only work when the
perf.data comes from same binary.

Here is an example.
perf diff -s symoff  v1_1_8_1perf.data v1_1_8_2perf.data

 Event 'cycles'

 Baseline    Delta  Symbol + Offset
 ........  .......  ...............................

     0.00%           __update_cpu_load+0xcc
                     _raw_spin_lock_irqsave+0x24
                     _raw_spin_unlock_irqrestore+0xa
     0.00%           apic_timer_interrupt+0x0
                     apic_timer_interrupt+0x68
                     check_preempt_curr+0x1c
     0.00%           f1+0x20
     0.03%   +0.03%  f2+0x11
     0.03%   +0.01%  f2+0x16
     0.05%           f2+0x1b
     0.04%   -0.02%  f2+0x20
     0.03%           f2+0x25
     0.17%   +0.11%  f2+0x29
     0.15%           f2+0x2d
                     f2+0x30
     0.37%   +0.02%  f3+0x0
     0.18%   +0.03%  f3+0x1
     0.01%           f3+0x4
     0.18%   +0.04%  f3+0xb
    12.31%   +0.11%  f3+0xd
     0.03%           f3+0x10
     0.80%   -0.12%  f3+0x13
     6.66%   +0.09%  f3+0x17
     1.81%   -0.36%  f3+0x1b
     6.35%   +0.24%  f3+0x1d
     1.42%   -0.22%  f3+0x21
    66.83%   +0.22%  f3+0x25
     1.29%   -0.12%  f3+0x27
     1.22%   -0.04%  f3+0x28
     0.00%           load_balance+0x96
     0.00%           native_apic_mem_write+0x0
     0.00%           native_write_msr_safe+0xa
     0.00%           native_write_msr_safe+0xd
     0.00%           rb_erase+0x381
                     resched_curr+0x5
                     restore_args+0x4
     0.00%           run_timer_softirq+0x29f
                     select_task_rq_fair+0x9
     0.00%           select_task_rq_fair+0x1d9
                     task_tick_fair+0x46
     0.00%           task_tick_fair+0x1ce
                     task_waking_fair+0x27
     0.00%           try_to_wake_up+0x158
                     update_cfs_rq_blocked_load+0x99
     0.00%           update_cpu_load_active+0x3b
                     update_group_capacity+0x150
                     update_wall_time+0x3c6

Signed-off-by: Kan Liang <kan.liang@intel.com>
---
 tools/perf/Documentation/perf-diff.txt |  8 +++-
 tools/perf/builtin-diff.c              |  2 +-
 tools/perf/util/hist.c                 |  5 ++-
 tools/perf/util/hist.h                 |  1 +
 tools/perf/util/sort.c                 | 67 ++++++++++++++++++++++++++++++++++
 tools/perf/util/sort.h                 |  2 +
 6 files changed, 80 insertions(+), 5 deletions(-)

diff --git a/tools/perf/Documentation/perf-diff.txt b/tools/perf/Documentation/perf-diff.txt
index e463caa..9e13911 100644
--- a/tools/perf/Documentation/perf-diff.txt
+++ b/tools/perf/Documentation/perf-diff.txt
@@ -50,8 +50,12 @@ OPTIONS
 
 -s::
 --sort=::
-	Sort by key(s): pid, comm, dso, symbol, cpu, parent, srcline.
-	Please see description of --sort in the perf-report man page.
+	Sort by key(s): pid, comm, dso, symbol, cpu, parent, srcline, symoff.
+
+	- symoff: exact symbol +  offset address executed at the time of sample.
+	(for same binary compare)
+
+	For other keys, please see description of --sort in the perf-report man page.
 
 -t::
 --field-separator=::
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 1ce425d..03a4001 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -744,7 +744,7 @@ static const struct option options[] = {
 	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",
 		   "only consider these symbols"),
 	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
-		   "sort by key(s): pid, comm, dso, symbol, parent, cpu, srcline, ..."
+		   "sort by key(s): pid, comm, dso, symbol, parent, cpu, srcline, symoff, ..."
 		   " Please refer the man page for the complete list."),
 	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
 		   "separator for columns, no spaces will be added between "
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 6e88b9e..3d8a71b 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -67,13 +67,14 @@ void hists__calc_col_len(struct hists *hists, struct hist_entry *h)
 		symlen = h->ms.sym->namelen + 4;
 		if (verbose)
 			symlen += BITS_PER_LONG / 4 + 2 + 3;
-		hists__new_col_len(hists, HISTC_SYMBOL, symlen);
 	} else {
 		symlen = unresolved_col_width + 4 + 2;
-		hists__new_col_len(hists, HISTC_SYMBOL, symlen);
 		hists__set_unres_dso_col_len(hists, HISTC_DSO);
 	}
 
+	hists__new_col_len(hists, HISTC_SYMBOL, symlen);
+	hists__new_col_len(hists, HISTC_SYMOFF, symlen);
+
 	len = thread__comm_len(h->thread);
 	if (hists__new_col_len(hists, HISTC_COMM, len))
 		hists__set_col_len(hists, HISTC_THREAD, len + 6);
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index d0ef9a1..874b203 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -24,6 +24,7 @@ enum hist_filter {
 
 enum hist_column {
 	HISTC_SYMBOL,
+	HISTC_SYMOFF,
 	HISTC_DSO,
 	HISTC_THREAD,
 	HISTC_COMM,
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index bea2e07..49ad000 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -280,6 +280,65 @@ struct sort_entry sort_sym = {
 	.se_width_idx	= HISTC_SYMBOL,
 };
 
+static int64_t
+sort__symoff_cmp(struct hist_entry *left, struct hist_entry *right)
+{
+	return _sort__addr_cmp(left->ip, right->ip);
+}
+
+static int64_t
+sort__symoff_collapse(struct hist_entry *left, struct hist_entry *right)
+{
+	struct symbol *sym_l = left->ms.sym;
+	struct symbol *sym_r = right->ms.sym;
+	u64 symoff_l, symoff_r;
+	int64_t ret;
+
+	if (!sym_l || !sym_r)
+		return cmp_null(sym_l, sym_r);
+
+	ret = strcmp(sym_r->name, sym_l->name);
+	if (ret)
+		return ret;
+
+
+	symoff_l = left->ip - sym_l->start;
+	symoff_r = right->ip - sym_r->start;
+
+	return (int64_t)(symoff_r - symoff_l);
+}
+
+static int hist_entry__symoff_snprintf(struct hist_entry *he, char *bf,
+				    size_t size, unsigned int width)
+{
+	struct map *map = he->ms.map;
+	struct symbol *sym = he->ms.sym;
+	size_t ret = 0;
+
+	if (sym) {
+		ret += repsep_snprintf(bf + ret, size - ret, "%s", sym->name);
+		ret += repsep_snprintf(bf + ret, size - ret, "+0x%llx",
+				       he->ip - sym->start);
+
+	} else {
+		size_t len = BITS_PER_LONG / 4;
+
+		ret += repsep_snprintf(bf + ret, size - ret, "%-#.*llx", len,
+				       map ? map->unmap_ip(map, he->ip) : he->ip);
+	}
+
+	ret += repsep_snprintf(bf + ret, size - ret, "%-*s",
+			       width - ret, "");
+	return ret;
+}
+
+struct sort_entry sort_symoff = {
+	.se_header	= "Symbol + Offset",
+	.se_cmp		= sort__symoff_cmp,
+	.se_snprintf	= hist_entry__symoff_snprintf,
+	.se_width_idx	= HISTC_SYMOFF,
+};
+
 /* --sort srcline */
 
 static int64_t
@@ -1172,6 +1231,7 @@ static struct sort_dimension common_sort_dimensions[] = {
 	DIM(SORT_COMM, "comm", sort_comm),
 	DIM(SORT_DSO, "dso", sort_dso),
 	DIM(SORT_SYM, "symbol", sort_sym),
+	DIM(SORT_SYMOFF, "symoff", sort_symoff),
 	DIM(SORT_PARENT, "parent", sort_parent),
 	DIM(SORT_CPU, "cpu", sort_cpu),
 	DIM(SORT_SRCLINE, "srcline", sort_srcline),
@@ -1443,6 +1503,13 @@ int sort_dimension__add(const char *tok)
 
 		} else if (sd->entry == &sort_dso) {
 			sort__has_dso = 1;
+		} else if (sd->entry == &sort_symoff) {
+			/*
+			 * For symoff sort key, not only the offset but also the
+			 * symbol name should be compared.
+			 */
+			if (sort__mode == SORT_MODE__DIFF)
+				sd->entry->se_collapse = sort__symoff_collapse;
 		}
 
 		return __sort_dimension__add(sd);
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index c03e4ff..ea0122f 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -38,6 +38,7 @@ extern enum sort_mode sort__mode;
 extern struct sort_entry sort_comm;
 extern struct sort_entry sort_dso;
 extern struct sort_entry sort_sym;
+extern struct sort_entry sort_symoff;
 extern struct sort_entry sort_parent;
 extern struct sort_entry sort_dso_from;
 extern struct sort_entry sort_dso_to;
@@ -161,6 +162,7 @@ enum sort_type {
 	SORT_COMM,
 	SORT_DSO,
 	SORT_SYM,
+	SORT_SYMOFF,
 	SORT_PARENT,
 	SORT_CPU,
 	SORT_SRCLINE,
-- 
1.8.3.2