1 files changed, 233 insertions, 0 deletions
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
new file mode 100644
index 00000000..e8219990
--- /dev/null
+++ b/tools/perf/builtin-diff.c
@@ -0,0 +1,233 @@
+/*
+ * builtin-diff.c
+ *
+ * Builtin diff command: Analyze two perf.data input files, look up and read
+ * DSOs and symbol information, sort them and produce a diff.
+ */
+#include "builtin.h"
+
+#include "util/debug.h"
+#include "util/event.h"
+#include "util/hist.h"
+#include "util/session.h"
+#include "util/sort.h"
+#include "util/symbol.h"
+#include "util/util.h"
+
+#include <stdlib.h>
+
+static char const *input_old = "perf.data.old",
+		  *input_new = "perf.data";
+static char	  diff__default_sort_order[] = "dso,symbol";
+static bool  force;
+static bool show_displacement;
+
+static int hists__add_entry(struct hists *self,
+			    struct addr_location *al, u64 period)
+{
+	if (__hists__add_entry(self, al, NULL, period) != NULL)
+		return 0;
+	return -ENOMEM;
+}
+
+static int diff__process_sample_event(union perf_event *event,
+				      struct perf_sample *sample,
+				      struct perf_evsel *evsel __used,
+				      struct perf_session *session)
+{
+	struct addr_location al;
+
+	if (perf_event__preprocess_sample(event, session, &al, sample, NULL) < 0) {
+		pr_warning("problem processing %d event, skipping it.\n",
+			   event->header.type);
+		return -1;
+	}
+
+	if (al.filtered || al.sym == NULL)
+		return 0;
+
+	if (hists__add_entry(&session->hists, &al, sample->period)) {
+		pr_warning("problem incrementing symbol period, skipping event\n");
+		return -1;
+	}
+
+	session->hists.stats.total_period += sample->period;
+	return 0;
+}
+
+static struct perf_event_ops event_ops = {
+	.sample	= diff__process_sample_event,
+	.mmap	= perf_event__process_mmap,
+	.comm	= perf_event__process_comm,
+	.exit	= perf_event__process_task,
+	.fork	= perf_event__process_task,
+	.lost	= perf_event__process_lost,
+	.ordered_samples = true,
+	.ordering_requires_timestamps = true,
+};
+
+static void perf_session__insert_hist_entry_by_name(struct rb_root *root,
+						    struct hist_entry *he)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent = NULL;
+	struct hist_entry *iter;
+
+	while (*p != NULL) {
+		parent = *p;
+		iter = rb_entry(parent, struct hist_entry, rb_node);
+		if (hist_entry__cmp(he, iter) < 0)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+
+	rb_link_node(&he->rb_node, parent, p);
+	rb_insert_color(&he->rb_node, root);
+}
+
+static void hists__resort_entries(struct hists *self)
+{
+	unsigned long position = 1;
+	struct rb_root tmp = RB_ROOT;
+	struct rb_node *next = rb_first(&self->entries);
+
+	while (next != NULL) {
+		struct hist_entry *n = rb_entry(next, struct hist_entry, rb_node);
+
+		next = rb_next(&n->rb_node);
+		rb_erase(&n->rb_node, &self->entries);
+		n->position = position++;
+		perf_session__insert_hist_entry_by_name(&tmp, n);
+	}
+
+	self->entries = tmp;
+}
+
+static void hists__set_positions(struct hists *self)
+{
+	hists__output_resort(self);
+	hists__resort_entries(self);
+}
+
+static struct hist_entry *hists__find_entry(struct hists *self,
+					    struct hist_entry *he)
+{
+	struct rb_node *n = self->entries.rb_node;
+
+	while (n) {
+		struct hist_entry *iter = rb_entry(n, struct hist_entry, rb_node);
+		int64_t cmp = hist_entry__cmp(he, iter);
+
+		if (cmp < 0)
+			n = n->rb_left;
+		else if (cmp > 0)
+			n = n->rb_right;
+		else 
+			return iter;
+	}
+
+	return NULL;
+}
+
+static void hists__match(struct hists *older, struct hists *newer)
+{
+	struct rb_node *nd;
+
+	for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {
+		struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
+		pos->pair = hists__find_entry(older, pos);
+	}
+}
+
+static int __cmd_diff(void)
+{
+	int ret, i;
+	struct perf_session *session[2];
+
+	session[0] = perf_session__new(input_old, O_RDONLY, force, false, &event_ops);
+	session[1] = perf_session__new(input_new, O_RDONLY, force, false, &event_ops);
+	if (session[0] == NULL || session[1] == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < 2; ++i) {
+		ret = perf_session__process_events(session[i], &event_ops);
+		if (ret)
+			goto out_delete;
+	}
+
+	hists__output_resort(&session[1]->hists);
+	if (show_displacement)
+		hists__set_positions(&session[0]->hists);
+
+	hists__match(&session[0]->hists, &session[1]->hists);
+	hists__fprintf(&session[1]->hists, &session[0]->hists,
+		       show_displacement, stdout);
+out_delete:
+	for (i = 0; i < 2; ++i)
+		perf_session__delete(session[i]);
+	return ret;
+}
+
+static const char * const diff_usage[] = {
+	"perf diff [<options>] [old_file] [new_file]",
+	NULL,
+};
+
+static const struct option options[] = {
+	OPT_INCR('v', "verbose", &verbose,
+		    "be more verbose (show symbol address, etc)"),
+	OPT_BOOLEAN('M', "displacement", &show_displacement,
+		    "Show position displacement relative to baseline"),
+	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
+		    "dump raw trace in ASCII"),
+	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
+	OPT_BOOLEAN('m', "modules", &symbol_conf.use_modules,
+		    "load module symbols - WARNING: use only with -k and LIVE kernel"),
+	OPT_STRING('d', "dsos", &symbol_conf.dso_list_str, "dso[,dso...]",
+		   "only consider symbols in these dsos"),
+	OPT_STRING('C', "comms", &symbol_conf.comm_list_str, "comm[,comm...]",
+		   "only consider symbols in these comms"),
+	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"),
+	OPT_STRING('t', "field-separator", &symbol_conf.field_sep, "separator",
+		   "separator for columns, no spaces will be added between "
+		   "columns '.' is reserved."),
+	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
+		    "Look for files with symbols relative to this directory"),
+	OPT_END()
+};
+
+int cmd_diff(int argc, const char **argv, const char *prefix __used)
+{
+	sort_order = diff__default_sort_order;
+	argc = parse_options(argc, argv, options, diff_usage, 0);
+	if (argc) {
+		if (argc > 2)
+			usage_with_options(diff_usage, options);
+		if (argc == 2) {
+			input_old = argv[0];
+			input_new = argv[1];
+		} else
+			input_new = argv[0];
+	} else if (symbol_conf.default_guest_vmlinux_name ||
+		   symbol_conf.default_guest_kallsyms) {
+		input_old = "perf.data.host";
+		input_new = "perf.data.guest";
+	}
+
+	symbol_conf.exclude_other = false;
+	if (symbol__init() < 0)
+		return -1;
+
+	setup_sorting(diff_usage, options);
+	setup_pager();
+
+	sort_entry__setup_elide(&sort_dso, symbol_conf.dso_list, "dso", NULL);
+	sort_entry__setup_elide(&sort_comm, symbol_conf.comm_list, "comm", NULL);
+	sort_entry__setup_elide(&sort_sym, symbol_conf.sym_list, "symbol", NULL);
+
+	return __cmd_diff();
+}