diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index dc85392a5ac7..35af0dc8ccb4 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -80,9 +80,10 @@ OPTIONS
 --dump-raw-trace::
         Dump raw trace in ASCII.
 
--g [type,min,order]::
+-g [type,min[,limit],order]::
 --call-graph::
-        Display call chains using type, min percent threshold and order.
+        Display call chains using type, min percent threshold, optional print
+	limit and order.
 	type can be either:
 	- flat: single column, linear exposure of call chains.
 	- graph: use a graph tree, displaying absolute overhead rates.
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 766fa0a91a32..f8fd14fb62ec 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -700,6 +700,7 @@ const struct option record_options[] = {
 	OPT_BOOLEAN('d', "data", &record.opts.sample_address,
 		    "Sample addresses"),
 	OPT_BOOLEAN('T', "timestamp", &record.opts.sample_time, "Sample timestamps"),
+	OPT_BOOLEAN('P', "period", &record.opts.period, "Sample period"),
 	OPT_BOOLEAN('n', "no-samples", &record.opts.no_samples,
 		    "don't sample"),
 	OPT_BOOLEAN('N', "no-buildid-cache", &record.no_buildid_cache,
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index ece7c5d3f504..b2654c9fb5c6 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -407,7 +407,7 @@ parse_callchain_opt(const struct option *opt, const char *arg, int unset)
 		goto setup;
 
 	if (tok2[0] != 'c') {
-		callchain_param.print_limit = strtod(tok2, &endptr);
+		callchain_param.print_limit = strtoul(tok2, &endptr, 0);
 		tok2 = strtok(NULL, ",");
 		if (!tok2)
 			goto setup;
@@ -485,8 +485,8 @@ int cmd_report(int argc, const char **argv, const char *prefix __used)
 		   "regex filter to identify parent, see: '--sort parent'"),
 	OPT_BOOLEAN('x', "exclude-other", &symbol_conf.exclude_other,
 		    "Only display entries with parent-match"),
-	OPT_CALLBACK_DEFAULT('g', "call-graph", &report, "output_type,min_percent, call_order",
-		     "Display callchains using output_type (graph, flat, fractal, or none) , min percent threshold and callchain order. "
+	OPT_CALLBACK_DEFAULT('g', "call-graph", &report, "output_type,min_percent[,print_limit],call_order",
+		     "Display callchains using output_type (graph, flat, fractal, or none) , min percent threshold, optional print limit and callchain order. "
 		     "Default: fractal,0.5,callee", &parse_callchain_opt, callchain_default_opt),
 	OPT_BOOLEAN('G', "inverted", &report.inverted_callchain,
 		    "alias for inverted call graph"),
diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index 6173f780dce0..2b9a7f497a20 100644
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -603,7 +603,7 @@ out_free_threads:
 
 #define TEST_ASSERT_VAL(text, cond) \
 do { \
-	if (!cond) { \
+	if (!(cond)) { \
 		pr_debug("FAILED %s:%d %s\n", __FILE__, __LINE__, text); \
 		return -1; \
 	} \
@@ -759,6 +759,103 @@ static int test__checkevent_breakpoint_w(struct perf_evlist *evlist)
 	return 0;
 }
 
+static int test__checkevent_tracepoint_modifier(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = list_entry(evlist->entries.next,
+					      struct perf_evsel, node);
+
+	TEST_ASSERT_VAL("wrong exclude_user", evsel->attr.exclude_user);
+	TEST_ASSERT_VAL("wrong exclude_kernel", !evsel->attr.exclude_kernel);
+	TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
+	TEST_ASSERT_VAL("wrong precise_ip", !evsel->attr.precise_ip);
+
+	return test__checkevent_tracepoint(evlist);
+}
+
+static int
+test__checkevent_tracepoint_multi_modifier(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel;
+
+	TEST_ASSERT_VAL("wrong number of entries", evlist->nr_entries > 1);
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		TEST_ASSERT_VAL("wrong exclude_user",
+				!evsel->attr.exclude_user);
+		TEST_ASSERT_VAL("wrong exclude_kernel",
+				evsel->attr.exclude_kernel);
+		TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
+		TEST_ASSERT_VAL("wrong precise_ip", !evsel->attr.precise_ip);
+	}
+
+	return test__checkevent_tracepoint_multi(evlist);
+}
+
+static int test__checkevent_raw_modifier(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = list_entry(evlist->entries.next,
+					      struct perf_evsel, node);
+
+	TEST_ASSERT_VAL("wrong exclude_user", evsel->attr.exclude_user);
+	TEST_ASSERT_VAL("wrong exclude_kernel", !evsel->attr.exclude_kernel);
+	TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
+	TEST_ASSERT_VAL("wrong precise_ip", evsel->attr.precise_ip);
+
+	return test__checkevent_raw(evlist);
+}
+
+static int test__checkevent_numeric_modifier(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = list_entry(evlist->entries.next,
+					      struct perf_evsel, node);
+
+	TEST_ASSERT_VAL("wrong exclude_user", evsel->attr.exclude_user);
+	TEST_ASSERT_VAL("wrong exclude_kernel", evsel->attr.exclude_kernel);
+	TEST_ASSERT_VAL("wrong exclude_hv", !evsel->attr.exclude_hv);
+	TEST_ASSERT_VAL("wrong precise_ip", evsel->attr.precise_ip);
+
+	return test__checkevent_numeric(evlist);
+}
+
+static int test__checkevent_symbolic_name_modifier(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = list_entry(evlist->entries.next,
+					      struct perf_evsel, node);
+
+	TEST_ASSERT_VAL("wrong exclude_user", evsel->attr.exclude_user);
+	TEST_ASSERT_VAL("wrong exclude_kernel", evsel->attr.exclude_kernel);
+	TEST_ASSERT_VAL("wrong exclude_hv", !evsel->attr.exclude_hv);
+	TEST_ASSERT_VAL("wrong precise_ip", !evsel->attr.precise_ip);
+
+	return test__checkevent_symbolic_name(evlist);
+}
+
+static int test__checkevent_symbolic_alias_modifier(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = list_entry(evlist->entries.next,
+					      struct perf_evsel, node);
+
+	TEST_ASSERT_VAL("wrong exclude_user", !evsel->attr.exclude_user);
+	TEST_ASSERT_VAL("wrong exclude_kernel", evsel->attr.exclude_kernel);
+	TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
+	TEST_ASSERT_VAL("wrong precise_ip", !evsel->attr.precise_ip);
+
+	return test__checkevent_symbolic_alias(evlist);
+}
+
+static int test__checkevent_genhw_modifier(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel = list_entry(evlist->entries.next,
+					      struct perf_evsel, node);
+
+	TEST_ASSERT_VAL("wrong exclude_user", evsel->attr.exclude_user);
+	TEST_ASSERT_VAL("wrong exclude_kernel", !evsel->attr.exclude_kernel);
+	TEST_ASSERT_VAL("wrong exclude_hv", evsel->attr.exclude_hv);
+	TEST_ASSERT_VAL("wrong precise_ip", evsel->attr.precise_ip);
+
+	return test__checkevent_genhw(evlist);
+}
+
 static struct test__event_st {
 	const char *name;
 	__u32 type;
@@ -808,6 +905,34 @@ static struct test__event_st {
 		.name  = "mem:0:w",
 		.check = test__checkevent_breakpoint_w,
 	},
+	{
+		.name  = "syscalls:sys_enter_open:k",
+		.check = test__checkevent_tracepoint_modifier,
+	},
+	{
+		.name  = "syscalls:*:u",
+		.check = test__checkevent_tracepoint_multi_modifier,
+	},
+	{
+		.name  = "r1:kp",
+		.check = test__checkevent_raw_modifier,
+	},
+	{
+		.name  = "1:1:hp",
+		.check = test__checkevent_numeric_modifier,
+	},
+	{
+		.name  = "instructions:h",
+		.check = test__checkevent_symbolic_name_modifier,
+	},
+	{
+		.name  = "faults:u",
+		.check = test__checkevent_symbolic_alias_modifier,
+	},
+	{
+		.name  = "L1-dcache-load-miss:kp",
+		.check = test__checkevent_genhw_modifier,
+	},
 };
 
 #define TEST__EVENTS_CNT (sizeof(test__events) / sizeof(struct test__event_st))
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index ea804f5a8cc2..64f8bee31ced 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -200,6 +200,7 @@ struct perf_record_opts {
 	bool	     sample_time;
 	bool	     sample_id_all_avail;
 	bool	     system_wide;
+	bool	     period;
 	unsigned int freq;
 	unsigned int mmap_pages;
 	unsigned int user_freq;
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 80d9598db31a..0deac6a14b65 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -1,5 +1,8 @@
 /*
- * GIT - The information manager from hell
+ * config.c
+ *
+ * Helper functions for parsing config items.
+ * Originally copied from GIT source.
  *
  * Copyright (C) Linus Torvalds, 2005
  * Copyright (C) Johannes Schindelin, 2005
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 97c479bcb0dc..b7c7f39a8f6d 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -814,13 +814,14 @@ int perf_event__preprocess_sample(const union perf_event *event,
 	al->cpu = sample->cpu;
 
 	if (al->map) {
+		struct dso *dso = al->map->dso;
+
 		if (symbol_conf.dso_list &&
-		    (!al->map || !al->map->dso ||
-		     !(strlist__has_entry(symbol_conf.dso_list,
-					  al->map->dso->short_name) ||
-		       (al->map->dso->short_name != al->map->dso->long_name &&
-			strlist__has_entry(symbol_conf.dso_list,
-					   al->map->dso->long_name)))))
+		    (!dso || !(strlist__has_entry(symbol_conf.dso_list,
+						  dso->short_name) ||
+			       (dso->short_name != dso->long_name &&
+				strlist__has_entry(symbol_conf.dso_list,
+						   dso->long_name)))))
 			goto out_filtered;
 
 		al->sym = map__find_symbol(al->map, al->addr, filter);
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 8b19e7a1e881..963d63dde457 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -447,8 +447,10 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist,
 	evlist->mmap[idx].mask = mask;
 	evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, prot,
 				      MAP_SHARED, fd, 0);
-	if (evlist->mmap[idx].base == MAP_FAILED)
+	if (evlist->mmap[idx].base == MAP_FAILED) {
+		evlist->mmap[idx].base = NULL;
 		return -1;
+	}
 
 	perf_evlist__add_pollfd(evlist, fd);
 	return 0;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 4a8c8b02e9cc..667f3b78bb2c 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -108,6 +108,9 @@ void perf_evsel__config(struct perf_evsel *evsel, struct perf_record_opts *opts)
 	if (opts->system_wide)
 		attr->sample_type	|= PERF_SAMPLE_CPU;
 
+	if (opts->period)
+		attr->sample_type	|= PERF_SAMPLE_PERIOD;
+
 	if (opts->sample_id_all_avail &&
 	    (opts->sample_time || opts->system_wide ||
 	     !opts->no_inherit || opts->cpu_list))
@@ -457,7 +460,7 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
 		u32 val32[2];
 	} u;
 
-
+	memset(data, 0, sizeof(*data));
 	data->cpu = data->pid = data->tid = -1;
 	data->stream_id = data->id = data->time = -1ULL;
 
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 632b50c7bc26..215d50f2042e 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1757,7 +1757,7 @@ static int map_groups__set_modules_path_dir(struct map_groups *mg,
 		struct stat st;
 
 		/*sshfs might return bad dent->d_type, so we have to stat*/
-		sprintf(path, "%s/%s", dir_name, dent->d_name);
+		snprintf(path, sizeof(path), "%s/%s", dir_name, dent->d_name);
 		if (stat(path, &st))
 			continue;
 
@@ -1766,8 +1766,6 @@ static int map_groups__set_modules_path_dir(struct map_groups *mg,
 			    !strcmp(dent->d_name, ".."))
 				continue;
 
-			snprintf(path, sizeof(path), "%s/%s",
-				 dir_name, dent->d_name);
 			ret = map_groups__set_modules_path_dir(mg, path);
 			if (ret < 0)
 				goto out;
@@ -1788,9 +1786,6 @@ static int map_groups__set_modules_path_dir(struct map_groups *mg,
 			if (map == NULL)
 				continue;
 
-			snprintf(path, sizeof(path), "%s/%s",
-				 dir_name, dent->d_name);
-
 			long_name = strdup(path);
 			if (long_name == NULL) {
 				ret = -1;
@@ -2609,10 +2604,10 @@ int symbol__init(void)
 	symbol_conf.initialized = true;
 	return 0;
 
-out_free_dso_list:
-	strlist__delete(symbol_conf.dso_list);
 out_free_comm_list:
 	strlist__delete(symbol_conf.comm_list);
+out_free_dso_list:
+	strlist__delete(symbol_conf.dso_list);
 	return -1;
 }
 
diff --git a/tools/perf/util/usage.c b/tools/perf/util/usage.c
index e16bf9a707e8..d76d1c0ff98f 100644
--- a/tools/perf/util/usage.c
+++ b/tools/perf/util/usage.c
@@ -1,5 +1,8 @@
 /*
- * GIT - The information manager from hell
+ * usage.c
+ *
+ * Various reporting routines.
+ * Originally copied from GIT source.
  *
  * Copyright (C) Linus Torvalds, 2005
  */
diff --git a/tools/perf/util/values.c b/tools/perf/util/values.c
index bdd33470b235..697c8b4e59cc 100644
--- a/tools/perf/util/values.c
+++ b/tools/perf/util/values.c
@@ -32,6 +32,7 @@ void perf_read_values_destroy(struct perf_read_values *values)
 
 	for (i = 0; i < values->threads; i++)
 		free(values->value[i]);
+	free(values->value);
 	free(values->pid);
 	free(values->tid);
 	free(values->counterrawid);