Merge tag 'perf-core-for-mingo-4.11-20170213' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

New features:

 - Introduce the 'delta-abs' 'perf diff' compute method, that orders the
   histogram entries by the absolute value of the percentage delta for a
   function in two perf.data files, i.e. the functions that changed the
   most (increase or decrease in samples) comes first (Namhyung Kim)

User visible changes:

 - Improve message about tweaking the kernel.perf_event_paranoid setting,
   telling how to make the change permanent by editing /etc/sysctl.conf
   (Arnaldo Carvalho de Melo)

Infrastructure changes:

 - Introduce linux/compiler-gcc.h as a counterpart to the kernel's,
   initially containing the definition of __fallthrough, more to
   come (__maybe_unused, etc) (Arnaldo Carvalho de Melo)

 - Fixes for problems uncovered by building tools/perf with clang, such
   as always true tests of arrays against NULL and variables that sometimes
   were used without being initialized (Arnaldo Carvalho de Melo, Steven Rostedt)

 - Before loading a new ELF, clear global variables set by the
   samples/bpf loader (Mickaël Salaün)

 - Ignore already processed ELF sections in the samples/bpf
   loader (Mickaël Salaün)

 - Fix compile error in the scripting code with some perl5
   versions (Wang YanQing)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 74 insertions, 4 deletions

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 933aeec46f4a..70a289347591 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -17,6 +17,7 @@
 #include "util/symbol.h"
 #include "util/util.h"
 #include "util/data.h"
+#include "util/config.h"
 
 #include <stdlib.h>
 #include <math.h>
@@ -30,6 +31,7 @@ enum {
 	PERF_HPP_DIFF__RATIO,
 	PERF_HPP_DIFF__WEIGHTED_DIFF,
 	PERF_HPP_DIFF__FORMULA,
+	PERF_HPP_DIFF__DELTA_ABS,
 
 	PERF_HPP_DIFF__MAX_INDEX
 };
@@ -64,7 +66,7 @@ static bool force;
 static bool show_period;
 static bool show_formula;
 static bool show_baseline_only;
-static unsigned int sort_compute;
+static unsigned int sort_compute = 1;
 
 static s64 compute_wdiff_w1;
 static s64 compute_wdiff_w2;
@@ -73,19 +75,22 @@ enum {
 	COMPUTE_DELTA,
 	COMPUTE_RATIO,
 	COMPUTE_WEIGHTED_DIFF,
+	COMPUTE_DELTA_ABS,
 	COMPUTE_MAX,
 };
 
 const char *compute_names[COMPUTE_MAX] = {
 	[COMPUTE_DELTA] = "delta",
+	[COMPUTE_DELTA_ABS] = "delta-abs",
 	[COMPUTE_RATIO] = "ratio",
 	[COMPUTE_WEIGHTED_DIFF] = "wdiff",
 };
 
-static int compute;
+static int compute = COMPUTE_DELTA_ABS;
 
 static int compute_2_hpp[COMPUTE_MAX] = {
 	[COMPUTE_DELTA]		= PERF_HPP_DIFF__DELTA,
+	[COMPUTE_DELTA_ABS]	= PERF_HPP_DIFF__DELTA_ABS,
 	[COMPUTE_RATIO]		= PERF_HPP_DIFF__RATIO,
 	[COMPUTE_WEIGHTED_DIFF]	= PERF_HPP_DIFF__WEIGHTED_DIFF,
 };
@@ -111,6 +116,10 @@ static struct header_column {
 		.name  = "Delta",
 		.width = 7,
 	},
+	[PERF_HPP_DIFF__DELTA_ABS] = {
+		.name  = "Delta Abs",
+		.width = 7,
+	},
 	[PERF_HPP_DIFF__RATIO] = {
 		.name  = "Ratio",
 		.width = 14,
@@ -298,6 +307,7 @@ static int formula_fprintf(struct hist_entry *he, struct hist_entry *pair,
 {
 	switch (compute) {
 	case COMPUTE_DELTA:
+	case COMPUTE_DELTA_ABS:
 		return formula_delta(he, pair, buf, size);
 	case COMPUTE_RATIO:
 		return formula_ratio(he, pair, buf, size);
@@ -461,6 +471,7 @@ static void hists__precompute(struct hists *hists)
 
 			switch (compute) {
 			case COMPUTE_DELTA:
+			case COMPUTE_DELTA_ABS:
 				compute_delta(he, pair);
 				break;
 			case COMPUTE_RATIO:
@@ -498,6 +509,13 @@ __hist_entry__cmp_compute(struct hist_entry *left, struct hist_entry *right,
 
 		return cmp_doubles(l, r);
 	}
+	case COMPUTE_DELTA_ABS:
+	{
+		double l = fabs(left->diff.period_ratio_delta);
+		double r = fabs(right->diff.period_ratio_delta);
+
+		return cmp_doubles(l, r);
+	}
 	case COMPUTE_RATIO:
 	{
 		double l = left->diff.period_ratio;
@@ -564,7 +582,7 @@ hist_entry__cmp_compute_idx(struct hist_entry *left, struct hist_entry *right,
 	if (!p_left || !p_right)
 		return p_left ? -1 : 1;
 
-	if (c != COMPUTE_DELTA) {
+	if (c != COMPUTE_DELTA && c != COMPUTE_DELTA_ABS) {
 		/*
 		 * The delta can be computed without the baseline, but
 		 * others are not.  Put those entries which have no
@@ -607,6 +625,15 @@ hist_entry__cmp_delta(struct perf_hpp_fmt *fmt,
 }
 
 static int64_t
+hist_entry__cmp_delta_abs(struct perf_hpp_fmt *fmt,
+		      struct hist_entry *left, struct hist_entry *right)
+{
+	struct data__file *d = fmt_to_data_file(fmt);
+
+	return hist_entry__cmp_compute(right, left, COMPUTE_DELTA_ABS, d->idx);
+}
+
+static int64_t
 hist_entry__cmp_ratio(struct perf_hpp_fmt *fmt,
 		      struct hist_entry *left, struct hist_entry *right)
 {
@@ -633,6 +660,14 @@ hist_entry__cmp_delta_idx(struct perf_hpp_fmt *fmt __maybe_unused,
 }
 
 static int64_t
+hist_entry__cmp_delta_abs_idx(struct perf_hpp_fmt *fmt __maybe_unused,
+			      struct hist_entry *left, struct hist_entry *right)
+{
+	return hist_entry__cmp_compute_idx(right, left, COMPUTE_DELTA_ABS,
+					   sort_compute);
+}
+
+static int64_t
 hist_entry__cmp_ratio_idx(struct perf_hpp_fmt *fmt __maybe_unused,
 			  struct hist_entry *left, struct hist_entry *right)
 {
@@ -775,7 +810,7 @@ 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,ratio,wdiff:w1,w2 (default delta)",
+		     "delta,delta-abs,ratio,wdiff:w1,w2 (default delta-abs)",
 		     "Entries differential computation selection",
 		     setup_compute),
 	OPT_BOOLEAN('p', "period", &show_period,
@@ -945,6 +980,7 @@ hpp__entry_pair(struct hist_entry *he, struct hist_entry *pair,
 
 	switch (idx) {
 	case PERF_HPP_DIFF__DELTA:
+	case PERF_HPP_DIFF__DELTA_ABS:
 		if (pair->diff.computed)
 			diff = pair->diff.period_ratio_delta;
 		else
@@ -1118,6 +1154,10 @@ static void data__hpp_register(struct data__file *d, int idx)
 		fmt->color = hpp__color_wdiff;
 		fmt->sort  = hist_entry__cmp_wdiff;
 		break;
+	case PERF_HPP_DIFF__DELTA_ABS:
+		fmt->color = hpp__color_delta;
+		fmt->sort  = hist_entry__cmp_delta_abs;
+		break;
 	default:
 		fmt->sort  = hist_entry__cmp_nop;
 		break;
@@ -1195,6 +1235,9 @@ static int ui_init(void)
 	case COMPUTE_WEIGHTED_DIFF:
 		fmt->sort = hist_entry__cmp_wdiff_idx;
 		break;
+	case COMPUTE_DELTA_ABS:
+		fmt->sort = hist_entry__cmp_delta_abs_idx;
+		break;
 	default:
 		BUG_ON(1);
 	}
@@ -1249,6 +1292,31 @@ static int data_init(int argc, const char **argv)
 	return 0;
 }
 
+static int diff__config(const char *var, const char *value,
+			void *cb __maybe_unused)
+{
+	if (!strcmp(var, "diff.order")) {
+		sort_compute = perf_config_int(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "diff.compute")) {
+		if (!strcmp(value, "delta")) {
+			compute = COMPUTE_DELTA;
+		} else if (!strcmp(value, "delta-abs")) {
+			compute = COMPUTE_DELTA_ABS;
+		} else if (!strcmp(value, "ratio")) {
+			compute = COMPUTE_RATIO;
+		} else if (!strcmp(value, "wdiff")) {
+			compute = COMPUTE_WEIGHTED_DIFF;
+		} else {
+			pr_err("Invalid compute method: %s\n", value);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
 int cmd_diff(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	int ret = hists__init();
@@ -1256,6 +1324,8 @@ int cmd_diff(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (ret < 0)
 		return ret;
 
+	perf_config(diff__config, NULL);
+
 	argc = parse_options(argc, argv, options, diff_usage, 0);
 
 	if (symbol__init(NULL) < 0)