[PATCH 11/14] perf diff: Change diff command to work over multiple data files

[Jiri Olsa <jolsa@redhat.com>]

Adding diff command the flexibility to specify multiple data
files on input. If not input file is given the standard behaviour
stands and diff inspects 'perf.data' and 'perf.data.old' files.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-diff.c | 99 +++++++++++++++++++++++++++++++----------------
 1 file changed, 66 insertions(+), 33 deletions(-)

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 3b3d21f..25a41e8 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -44,6 +44,7 @@ struct data__file {
 	struct perf_session	*session;
 	const char		*file;
 	int			 idx;
+	struct hists		*hists;
 	struct diff_hpp_fmt	 fmt[PERF_HPP_DIFF__MAX_INDEX];
 };
 
@@ -56,6 +57,7 @@ static int data__files_cnt;
 	     i++, d = &data__files[i])
 
 #define data__for_each_file(i, d) data__for_each_file_start(i, d, 0)
+#define data__for_each_file_new(i, d) data__for_each_file_start(i, d, 1)
 
 static char diff__default_sort_order[] = "dso,symbol";
 static bool force;
@@ -526,23 +528,19 @@ static void hists__compute_resort(struct hists *hists)
 	}
 }
 
-static void hists__process(struct hists *base, struct hists *new)
+static void hists__process(struct hists *hists)
 {
-	hists__match(base, new);
-
 	if (show_baseline_only)
-		hists__baseline_only(base);
-	else
-		hists__link(base, new);
+		hists__baseline_only(hists);
 
 	if (sort_compute) {
-		hists__precompute(base);
-		hists__compute_resort(base);
+		hists__precompute(hists);
+		hists__compute_resort(hists);
 	} else {
-		hists__output_resort(base);
+		hists__output_resort(hists);
 	}
 
-	hists__fprintf(base, true, 0, 0, stdout);
+	hists__fprintf(hists, true, 0, 0, stdout);
 }
 
 static void data__fprintf(void)
@@ -562,27 +560,40 @@ static void data__fprintf(void)
 
 static void data_process(void)
 {
-	struct perf_evlist *evlist_old = data__files[0].session->evlist;
-	struct perf_evlist *evlist_new = data__files[1].session->evlist;
-	struct perf_evsel *evsel_old;
+	struct perf_evlist *evlist_base = data__files[0].session->evlist;
+	struct perf_evsel *evsel_base;
 	bool first = true;
 
-	list_for_each_entry(evsel_old, &evlist_old->entries, node) {
-		struct perf_evsel *evsel_new;
+	list_for_each_entry(evsel_base, &evlist_base->entries, node) {
+		struct data__file *d;
+		int i;
 
-		evsel_new = evsel_match(evsel_old, evlist_new);
-		if (!evsel_new)
-			continue;
+		data__for_each_file_new(i, d) {
+			struct perf_evlist *evlist = d->session->evlist;
+			struct perf_evsel *evsel;
+
+			evsel = evsel_match(evsel_base, evlist);
+			if (!evsel)
+				continue;
+
+			d->hists = &evsel->hists;
+
+			hists__match(&evsel_base->hists, &evsel->hists);
+
+			if (!show_baseline_only)
+				hists__link(&evsel_base->hists,
+					    &evsel->hists);
+		}
 
 		fprintf(stdout, "%s# Event '%s'\n#\n", first ? "" : "\n",
-			perf_evsel__name(evsel_old));
+			perf_evsel__name(evsel_base));
 
 		first = false;
 
-		if (verbose)
+		if (data__files_cnt > 2)
 			data__fprintf();
 
-		hists__process(&evsel_old->hists, &evsel_new->hists);
+		hists__process(&evsel_base->hists);
 	}
 }
 
@@ -781,10 +792,29 @@ hpp__entry_pair(struct hist_entry *he, struct hist_entry *pair,
 	};
 }
 
+static struct hist_entry *get_pair(struct hist_entry *he,
+				   struct diff_hpp_fmt *dfmt)
+{
+	void *ptr = dfmt - dfmt->idx;
+	struct data__file *d = container_of(ptr, struct data__file, fmt);
+
+	if (hist_entry__has_pairs(he)) {
+		struct hist_entry *pair;
+
+		list_for_each_entry(pair, &he->pairs.head, pairs.node)
+			if (pair->hists == d->hists)
+				return pair;
+	}
+
+	return NULL;
+}
+
 static void
-__hpp__entry_global(struct hist_entry *he, int idx, char *buf, size_t size)
+__hpp__entry_global(struct hist_entry *he, struct diff_hpp_fmt *dfmt,
+		    char *buf, size_t size)
 {
-	struct hist_entry *pair = hist_entry__next_pair(he);
+	struct hist_entry *pair = get_pair(he, dfmt);
+	int idx = dfmt->idx;
 
 	/* baseline is special */
 	if (idx == PERF_HPP_DIFF__BASELINE)
@@ -804,7 +834,7 @@ static int hpp__entry_global(struct perf_hpp_fmt *_fmt, struct perf_hpp *hpp,
 		container_of(_fmt, struct diff_hpp_fmt, fmt);
 	char buf[MAX_COL_WIDTH] = " ";
 
-	__hpp__entry_global(he, dfmt->idx, buf, MAX_COL_WIDTH);
+	__hpp__entry_global(he, dfmt, buf, MAX_COL_WIDTH);
 
 	if (symbol_conf.field_sep)
 		return scnprintf(hpp->buf, hpp->size, "%s", buf);
@@ -833,7 +863,7 @@ static int hpp__width(struct perf_hpp_fmt *fmt,
 	return dfmt->header_width;
 }
 
-static void init_header(struct diff_hpp_fmt *dfmt)
+static void init_header(struct data__file *d, struct diff_hpp_fmt *dfmt)
 {
 #define MAX_HEADER_NAME 100
 	char buf_indent[MAX_HEADER_NAME];
@@ -848,6 +878,9 @@ static void init_header(struct diff_hpp_fmt *dfmt)
 	/* Only our defined HPP fmts should appear here. */
 	BUG_ON(!header);
 
+	if (data__files_cnt > 2)
+		scnprintf(buf, MAX_HEADER_NAME, "%s/%d", header, d->idx);
+
 #define NAME (data__files_cnt > 2 ? buf : header)
 	dfmt->header_width = width;
 	width = (int) strlen(NAME);
@@ -877,7 +910,7 @@ static void data__hpp_register(struct data__file *d, int idx)
 	if (idx == PERF_HPP_DIFF__BASELINE)
 		fmt->color = hpp__color_baseline;
 
-	init_header(dfmt);
+	init_header(d, dfmt);
 	perf_hpp__column_register(fmt);
 }
 
@@ -922,18 +955,18 @@ static int data_init(int argc, const char **argv)
 		"perf.data.old",
 		"perf.data",
 	};
+	bool use_default = true;
 	int i;
 
 	data__files_cnt = 2;
 
 	if (argc) {
-		if (argc > 2)
-			usage_with_options(diff_usage, options);
-		if (argc == 2) {
-			defaults[0] = argv[0];
-			defaults[1] = argv[1];
-		} else
+		if (argc == 1)
 			defaults[1] = argv[0];
+		else {
+			data__files_cnt = argc;
+			use_default = false;
+		}
 	} else if (symbol_conf.default_guest_vmlinux_name ||
 		   symbol_conf.default_guest_kallsyms) {
 		defaults[0] = "perf.data.host";
@@ -945,7 +978,7 @@ static int data_init(int argc, const char **argv)
 		return -ENOMEM;
 
 	data__for_each_file(i, d) {
-		d->file = defaults[i];
+		d->file = use_default ? defaults[i] : argv[i];
 		d->idx  = i;
 	}
 
-- 
1.7.11.7