perf lock: Introduce new tool "perf lock", for analyzing lock statistics

Adding new subcommand "perf lock" to perf.

I have a lot of remaining ToDos, but for now perf lock can
already provide minimal functionality for analyzing lock
statistics.
Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1264851813-8413-12-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/Makefile

@@ -456,6 +456,7 @@ BUILTIN_OBJS += builtin-top.o
 BUILTIN_OBJS += builtin-trace.o
 BUILTIN_OBJS += builtin-probe.o
 BUILTIN_OBJS += builtin-kmem.o
+BUILTIN_OBJS += builtin-lock.o
 
 PERFLIBS = $(LIB_FILE)
 

tools/perf/builtin-lock.c

+#include "builtin.h"
+#include "perf.h"
+
+#include "util/util.h"
+#include "util/cache.h"
+#include "util/symbol.h"
+#include "util/thread.h"
+#include "util/header.h"
+
+#include "util/parse-options.h"
+#include "util/trace-event.h"
+
+#include "util/debug.h"
+#include "util/session.h"
+
+#include <sys/types.h>
+#include <sys/prctl.h>
+#include <semaphore.h>
+#include <pthread.h>
+#include <math.h>
+#include <limits.h>
+
+#include <linux/list.h>
+#include <linux/hash.h>
+
+/* based on kernel/lockdep.c */
+#define LOCKHASH_BITS		12
+#define LOCKHASH_SIZE		(1UL << LOCKHASH_BITS)
+
+static struct list_head lockhash_table[LOCKHASH_SIZE];
+
+#define __lockhashfn(key)	hash_long((unsigned long)key, LOCKHASH_BITS)
+#define lockhashentry(key)	(lockhash_table + __lockhashfn((key)))
+
+#define LOCK_STATE_UNLOCKED 0	       /* initial state */
+#define LOCK_STATE_LOCKED 1
+
+struct lock_stat {
+	struct list_head hash_entry;
+	struct rb_node rb;	/* used for sorting */
+
+	/* FIXME: raw_field_value() returns unsigned long long,
+	 * so address of lockdep_map should be dealed as 64bit.
+	 * Is there more better solution? */
+	void *addr;	       /* address of lockdep_map, used as ID */
+	char *name;	       /* for strcpy(), we cannot use const */
+	char *file;
+	unsigned int line;
+
+	int state;
+	u64 prev_event_time;	/* timestamp of previous event */
+
+	unsigned int nr_acquired;
+	unsigned int nr_acquire;
+	unsigned int nr_contended;
+	unsigned int nr_release;
+
+	/* these times are in nano sec. */
+	u64 wait_time_total;
+	u64 wait_time_min;
+	u64 wait_time_max;
+};
+
+/* build simple key function one is bigger than two */
+#define SINGLE_KEY(member)					\
+	static int lock_stat_key_ ## member(struct lock_stat *one,	\
+					 struct lock_stat *two)		\
+	{								\
+		return one->member > two->member;			\
+	}
+
+SINGLE_KEY(nr_acquired)
+SINGLE_KEY(nr_contended)
+SINGLE_KEY(wait_time_total)
+SINGLE_KEY(wait_time_min)
+SINGLE_KEY(wait_time_max)
+
+struct lock_key {
+	/*
+	 * name: the value for specify by user
+	 * this should be simpler than raw name of member
+	 * e.g. nr_acquired -> acquired, wait_time_total -> wait_total
+	 */
+	const char *name;
+	int (*key)(struct lock_stat*, struct lock_stat*);
+};
+
+static const char *sort_key = "acquired";
+static int (*compare)(struct lock_stat *, struct lock_stat *);
+
+#define DEF_KEY_LOCK(name, fn_suffix)	\
+	{ #name, lock_stat_key_ ## fn_suffix }
+struct lock_key keys[] = {
+	DEF_KEY_LOCK(acquired, nr_acquired),
+	DEF_KEY_LOCK(contended, nr_contended),
+	DEF_KEY_LOCK(wait_total, wait_time_total),
+	DEF_KEY_LOCK(wait_min, wait_time_min),
+	DEF_KEY_LOCK(wait_max, wait_time_max),
+
+	/* extra comparisons much complicated should be here */
+
+	{ NULL, NULL }
+};
+
+static void select_key(void)
+{
+	int i;
+
+	for (i = 0; keys[i].name; i++) {
+		if (!strcmp(keys[i].name, sort_key)) {
+			compare = keys[i].key;
+			return;
+		}
+	}
+
+	die("Unknown compare key:%s\n", sort_key);
+}
+
+static struct rb_root result;	/* place to store sorted data */
+
+static void insert_to_result(struct lock_stat *st,
+			     int (*bigger)(struct lock_stat *,
+					   struct lock_stat *))
+{
+	struct rb_node **rb = &result.rb_node;
+	struct rb_node *parent = NULL;
+	struct lock_stat *p;
+
+	while (*rb) {
+		p = container_of(*rb, struct lock_stat, rb);
+		parent = *rb;
+
+		if (bigger(st, p))
+			rb = &(*rb)->rb_left;
+		else
+			rb = &(*rb)->rb_right;
+	}
+
+	rb_link_node(&st->rb, parent, rb);
+	rb_insert_color(&st->rb, &result);
+}
+
+/* returns left most element of result, and erase it */
+static struct lock_stat *pop_from_result(void)
+{
+	struct rb_node *node = result.rb_node;
+
+	if (!node)
+		return NULL;
+
+	while (node->rb_left)
+		node = node->rb_left;
+
+	rb_erase(node, &result);
+	return container_of(node, struct lock_stat, rb);
+}
+
+static struct lock_stat *lock_stat_findnew(void *addr, const char *name,
+					   const char *file, unsigned int line)
+{
+	struct list_head *entry = lockhashentry(addr);
+	struct lock_stat *ret, *new;
+
+	list_for_each_entry(ret, entry, hash_entry) {
+		if (ret->addr == addr)
+			return ret;
+	}
+
+	new = zalloc(sizeof(struct lock_stat));
+	if (!new)
+		goto alloc_failed;
+
+	new->addr = addr;
+	new->name = zalloc(sizeof(char) * strlen(name) + 1);
+	if (!new->name)
+		goto alloc_failed;
+	strcpy(new->name, name);
+	new->file = zalloc(sizeof(char) * strlen(file) + 1);
+	if (!new->file)
+		goto alloc_failed;
+	strcpy(new->file, file);
+	new->line = line;
+
+	/* LOCK_STATE_UNLOCKED == 0 isn't guaranteed forever */
+	new->state = LOCK_STATE_UNLOCKED;
+	new->wait_time_min = ULLONG_MAX;
+
+	list_add(&new->hash_entry, entry);
+	return new;
+
+alloc_failed:
+	die("memory allocation failed\n");
+}
+
+static char			const *input_name = "perf.data";
+
+static int			profile_cpu = -1;
+
+struct raw_event_sample {
+	u32 size;
+	char data[0];
+};
+
+struct trace_acquire_event {
+	void *addr;
+	const char *name;
+	const char *file;
+	unsigned int line;
+};
+
+struct trace_acquired_event {
+	void *addr;
+	const char *name;
+	const char *file;
+	unsigned int line;
+};
+
+struct trace_contended_event {
+	void *addr;
+	const char *name;
+	const char *file;
+	unsigned int line;
+};
+
+struct trace_release_event {
+	void *addr;
+	const char *name;
+	const char *file;
+	unsigned int line;
+};
+
+struct trace_lock_handler {
+	void (*acquire_event)(struct trace_acquire_event *,
+			      struct event *,
+			      int cpu,
+			      u64 timestamp,
+			      struct thread *thread);
+
+	void (*acquired_event)(struct trace_acquired_event *,
+			       struct event *,
+			       int cpu,
+			       u64 timestamp,
+			       struct thread *thread);
+
+	void (*contended_event)(struct trace_contended_event *,
+				struct event *,
+				int cpu,
+				u64 timestamp,
+				struct thread *thread);
+
+	void (*release_event)(struct trace_release_event *,
+			      struct event *,
+			      int cpu,
+			      u64 timestamp,
+			      struct thread *thread);
+};
+
+static void prof_lock_acquire_event(struct trace_acquire_event *acquire_event,
+			struct event *__event __used,
+			int cpu __used,
+			u64 timestamp,
+			struct thread *thread __used)
+{
+	struct lock_stat *st;
+
+	st = lock_stat_findnew(acquire_event->addr, acquire_event->name,
+			       acquire_event->file, acquire_event->line);
+
+	switch (st->state) {
+	case LOCK_STATE_UNLOCKED:
+		break;
+	case LOCK_STATE_LOCKED:
+		break;
+	default:
+		BUG_ON(1);
+		break;
+	}
+
+	st->prev_event_time = timestamp;
+}
+
+static void prof_lock_acquired_event(struct trace_acquired_event *acquired_event,
+			 struct event *__event __used,
+			 int cpu __used,
+			 u64 timestamp,
+			 struct thread *thread __used)
+{
+	struct lock_stat *st;
+
+	st = lock_stat_findnew(acquired_event->addr, acquired_event->name,
+			       acquired_event->file, acquired_event->line);
+
+	switch (st->state) {
+	case LOCK_STATE_UNLOCKED:
+		st->state = LOCK_STATE_LOCKED;
+		st->nr_acquired++;
+		break;
+	case LOCK_STATE_LOCKED:
+		break;
+	default:
+		BUG_ON(1);
+		break;
+	}
+
+	st->prev_event_time = timestamp;
+}
+
+static void prof_lock_contended_event(struct trace_contended_event *contended_event,
+			  struct event *__event __used,
+			  int cpu __used,
+			  u64 timestamp,
+			  struct thread *thread __used)
+{
+	struct lock_stat *st;
+
+	st = lock_stat_findnew(contended_event->addr, contended_event->name,
+			       contended_event->file, contended_event->line);
+
+	switch (st->state) {
+	case LOCK_STATE_UNLOCKED:
+		break;
+	case LOCK_STATE_LOCKED:
+		st->nr_contended++;
+		break;
+	default:
+		BUG_ON(1);
+		break;
+	}
+
+	st->prev_event_time = timestamp;
+}
+
+static void prof_lock_release_event(struct trace_release_event *release_event,
+			struct event *__event __used,
+			int cpu __used,
+			u64 timestamp,
+			struct thread *thread __used)
+{
+	struct lock_stat *st;
+	u64 hold_time;
+
+	st = lock_stat_findnew(release_event->addr, release_event->name,
+			       release_event->file, release_event->line);
+
+	switch (st->state) {
+	case LOCK_STATE_UNLOCKED:
+		break;
+	case LOCK_STATE_LOCKED:
+		st->state = LOCK_STATE_UNLOCKED;
+		hold_time = timestamp - st->prev_event_time;
+
+		if (timestamp < st->prev_event_time) {
+			/* terribly, this can happen... */
+			goto end;
+		}
+
+		if (st->wait_time_min > hold_time)
+			st->wait_time_min = hold_time;
+		if (st->wait_time_max < hold_time)
+			st->wait_time_max = hold_time;
+		st->wait_time_total += hold_time;
+
+		st->nr_release++;
+		break;
+	default:
+		BUG_ON(1);
+		break;
+	}
+
+end:
+	st->prev_event_time = timestamp;
+}
+
+/* lock oriented handlers */
+/* TODO: handlers for CPU oriented, thread oriented */
+static struct trace_lock_handler prof_lock_ops  = {
+	.acquire_event		= prof_lock_acquire_event,
+	.acquired_event		= prof_lock_acquired_event,
+	.contended_event	= prof_lock_contended_event,
+	.release_event		= prof_lock_release_event,
+};
+
+static struct trace_lock_handler *trace_handler;
+
+static void
+process_lock_acquire_event(void *data,
+			   struct event *event __used,
+			   int cpu __used,
+			   u64 timestamp __used,
+			   struct thread *thread __used)
+{
+	struct trace_acquire_event acquire_event;
+	u64 tmp;		/* this is required for casting... */
+
+	tmp = raw_field_value(event, "lockdep_addr", data);
+	memcpy(&acquire_event.addr, &tmp, sizeof(void *));
+	acquire_event.name = (char *)raw_field_ptr(event, "name", data);
+	acquire_event.file = (char *)raw_field_ptr(event, "file", data);
+	acquire_event.line =
+		(unsigned int)raw_field_value(event, "line", data);
+
+	if (trace_handler->acquire_event) {
+		trace_handler->acquire_event(&acquire_event,
+					     event, cpu, timestamp, thread);
+	}
+}
+
+static void
+process_lock_acquired_event(void *data,
+			    struct event *event __used,
+			    int cpu __used,
+			    u64 timestamp __used,
+			    struct thread *thread __used)
+{
+	struct trace_acquired_event acquired_event;
+	u64 tmp;		/* this is required for casting... */
+
+	tmp = raw_field_value(event, "lockdep_addr", data);
+	memcpy(&acquired_event.addr, &tmp, sizeof(void *));
+	acquired_event.name = (char *)raw_field_ptr(event, "name", data);
+	acquired_event.file = (char *)raw_field_ptr(event, "file", data);
+	acquired_event.line =
+		(unsigned int)raw_field_value(event, "line", data);
+
+	if (trace_handler->acquire_event) {
+		trace_handler->acquired_event(&acquired_event,
+					     event, cpu, timestamp, thread);
+	}
+}
+
+static void
+process_lock_contended_event(void *data,
+			     struct event *event __used,
+			     int cpu __used,
+			     u64 timestamp __used,
+			     struct thread *thread __used)
+{
+	struct trace_contended_event contended_event;
+	u64 tmp;		/* this is required for casting... */
+
+	tmp = raw_field_value(event, "lockdep_addr", data);
+	memcpy(&contended_event.addr, &tmp, sizeof(void *));
+	contended_event.name = (char *)raw_field_ptr(event, "name", data);
+	contended_event.file = (char *)raw_field_ptr(event, "file", data);
+	contended_event.line =
+		(unsigned int)raw_field_value(event, "line", data);
+
+	if (trace_handler->acquire_event) {
+		trace_handler->contended_event(&contended_event,
+					     event, cpu, timestamp, thread);
+	}
+}
+
+static void
+process_lock_release_event(void *data,
+			   struct event *event __used,
+			   int cpu __used,
+			   u64 timestamp __used,
+			   struct thread *thread __used)
+{
+	struct trace_release_event release_event;
+	u64 tmp;		/* this is required for casting... */
+
+	tmp = raw_field_value(event, "lockdep_addr", data);
+	memcpy(&release_event.addr, &tmp, sizeof(void *));
+	release_event.name = (char *)raw_field_ptr(event, "name", data);
+	release_event.file = (char *)raw_field_ptr(event, "file", data);
+	release_event.line =
+		(unsigned int)raw_field_value(event, "line", data);
+
+	if (trace_handler->acquire_event) {
+		trace_handler->release_event(&release_event,
+					     event, cpu, timestamp, thread);
+	}
+}
+
+static void
+process_raw_event(void *data, int cpu,
+		  u64 timestamp, struct thread *thread)
+{
+	struct event *event;
+	int type;
+
+	type = trace_parse_common_type(data);
+	event = trace_find_event(type);
+
+	if (!strcmp(event->name, "lock_acquire"))
+		process_lock_acquire_event(data, event, cpu, timestamp, thread);
+	if (!strcmp(event->name, "lock_acquired"))
+		process_lock_acquired_event(data, event, cpu, timestamp, thread);
+	if (!strcmp(event->name, "lock_contended"))
+		process_lock_contended_event(data, event, cpu, timestamp, thread);
+	if (!strcmp(event->name, "lock_release"))
+		process_lock_release_event(data, event, cpu, timestamp, thread);
+}
+
+static int process_sample_event(event_t *event, struct perf_session *session)
+{
+	struct thread *thread;
+	struct sample_data data;
+
+	bzero(&data, sizeof(struct sample_data));
+	event__parse_sample(event, session->sample_type, &data);
+	thread = perf_session__findnew(session, data.pid);
+
+	/*
+	 * FIXME: this causes warn on 32bit environment
+	 * because of (void *)data.ip (type of data.ip is u64)
+	 */
+/* 	dump_printf("(IP, %d): %d/%d: %p period: %llu\n", */
+/* 		    event->header.misc, */
+/* 		    data.pid, data.tid, (void *)data.ip, data.period); */
+
+	if (thread == NULL) {
+		pr_debug("problem processing %d event, skipping it.\n",
+			 event->header.type);
+		return -1;
+	}
+
+	dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
+
+	if (profile_cpu != -1 && profile_cpu != (int) data.cpu)
+		return 0;
+
+	process_raw_event(data.raw_data, data.cpu, data.time, thread);
+
+	return 0;
+}
+
+/* TODO: various way to print, coloring, nano or milli sec */
+static void print_result(void)
+{
+	struct lock_stat *st;
+	char cut_name[20];
+
+	printf("%18s ", "ID");
+	printf("%20s ", "Name");
+	printf("%10s ", "acquired");
+	printf("%10s ", "contended");
+
+	printf("%15s ", "total wait (ns)");
+	printf("%15s ", "max wait (ns)");
+	printf("%15s ", "min wait (ns)");
+
+	printf("\n\n");
+
+	while ((st = pop_from_result())) {
+		bzero(cut_name, 20);
+
+		printf("%p ", st->addr);
+
+		if (strlen(st->name) < 16) {
+			/* output raw name */
+			printf("%20s ", st->name);
+		} else {
+			strncpy(cut_name, st->name, 16);
+			cut_name[16] = '.';
+			cut_name[17] = '.';
+			cut_name[18] = '.';
+			cut_name[19] = '\0';
+			/* cut off name for saving output style */
+			printf("%20s ", cut_name);
+		}
+
+		printf("%10u ", st->nr_acquired);
+		printf("%10u ", st->nr_contended);
+
+		printf("%15llu ", st->wait_time_total);
+		printf("%15llu ", st->wait_time_max);
+		printf("%15llu ", st->wait_time_min == ULLONG_MAX ?
+		       0 : st->wait_time_min);
+		printf("\n");
+	}
+}
+
+static void dump_map(void)
+{
+	unsigned int i;
+	struct lock_stat *st;
+
+	for (i = 0; i < LOCKHASH_SIZE; i++) {
+		list_for_each_entry(st, &lockhash_table[i], hash_entry) {
+			printf("%p: %s (src: %s, line: %u)\n",
+			       st->addr, st->name, st->file, st->line);
+		}
+	}
+}
+
+static struct perf_event_ops eops = {
+	.sample	= process_sample_event,
+	.comm	= event__process_comm,
+};
+
+static struct perf_session *session;
+
+static int read_events(void)
+{
+	session = perf_session__new(input_name, O_RDONLY, 0);
+	if (!session)
+		die("Initializing perf session failed\n");
+
+	return perf_session__process_events(session, &eops);
+}
+
+static void sort_result(void)
+{
+	unsigned int i;
+	struct lock_stat *st;
+
+	for (i = 0; i < LOCKHASH_SIZE; i++) {
+		list_for_each_entry(st, &lockhash_table[i], hash_entry) {
+			insert_to_result(st, compare);
+		}
+	}
+}
+
+static void __cmd_prof(void)
+{
+	setup_pager();
+	select_key();
+	read_events();
+	sort_result();
+	print_result();
+}
+
+static const char * const prof_usage[] = {
+	"perf sched prof [<options>]",
+	NULL
+};
+
+static const struct option prof_options[] = {
+	OPT_STRING('k', "key", &sort_key, "acquired",
+		    "key for sorting"),
+	/* TODO: type */
+	OPT_END()
+};
+
+static const char * const lock_usage[] = {
+	"perf lock [<options>] {record|trace|prof}",
+	NULL
+};
+
+static const struct option lock_options[] = {
+	OPT_STRING('i', "input", &input_name, "file",
+		    "input file name"),
+	OPT_BOOLEAN('v', "verbose", &verbose,
+		    "be more verbose (show symbol address, etc)"),
+	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
+		    "dump raw trace in ASCII"),
+	OPT_END()
+};
+
+static const char *record_args[] = {
+	"record",
+	"-a",
+	"-R",
+	"-M",
+	"-f",
+	"-m", "1024",
+	"-c", "1",
+	"-e", "lock:lock_acquire:r",
+	"-e", "lock:lock_acquired:r",
+	"-e", "lock:lock_contended:r",
+	"-e", "lock:lock_release:r",
+};
+
+static int __cmd_record(int argc, const char **argv)
+{
+	unsigned int rec_argc, i, j;
+	const char **rec_argv;
+
+	rec_argc = ARRAY_SIZE(record_args) + argc - 1;
+	rec_argv = calloc(rec_argc + 1, sizeof(char *));
+
+	for (i = 0; i < ARRAY_SIZE(record_args); i++)
+		rec_argv[i] = strdup(record_args[i]);
+
+	for (j = 1; j < (unsigned int)argc; j++, i++)
+		rec_argv[i] = argv[j];
+
+	BUG_ON(i != rec_argc);
+
+	return cmd_record(i, rec_argv, NULL);
+}
+
+int cmd_lock(int argc, const char **argv, const char *prefix __used)
+{
+	unsigned int i;
+
+	symbol__init();
+	for (i = 0; i < LOCKHASH_SIZE; i++)
+		INIT_LIST_HEAD(lockhash_table + i);
+
+	argc = parse_options(argc, argv, lock_options, lock_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+	if (!argc)
+		usage_with_options(lock_usage, lock_options);
+
+	if (!strncmp(argv[0], "rec", 3)) {
+		return __cmd_record(argc, argv);
+	} else if (!strncmp(argv[0], "prof", 4)) {
+		trace_handler = &prof_lock_ops;
+		if (argc) {
+			argc = parse_options(argc, argv,
+					     prof_options, prof_usage, 0);
+			if (argc)
+				usage_with_options(prof_usage, prof_options);
+		}
+		__cmd_prof();
+	} else if (!strcmp(argv[0], "trace")) {
+		/* Aliased to 'perf trace' */
+		return cmd_trace(argc, argv, prefix);
+	} else if (!strcmp(argv[0], "map")) {
+		/* recycling prof_lock_ops */
+		trace_handler = &prof_lock_ops;
+		setup_pager();
+		read_events();
+		dump_map();
+	} else {
+		usage_with_options(lock_usage, lock_options);
+	}
+
+	return 0;
+}

tools/perf/builtin.h

@@ -31,5 +31,6 @@ extern int cmd_trace(int argc, const char **argv, const char *prefix);
 extern int cmd_version(int argc, const char **argv, const char *prefix);
 extern int cmd_probe(int argc, const char **argv, const char *prefix);
 extern int cmd_kmem(int argc, const char **argv, const char *prefix);
+extern int cmd_lock(int argc, const char **argv, const char *prefix);
 
 #endif

tools/perf/perf.c

@@ -303,6 +303,7 @@ static void handle_internal_command(int argc, const char **argv)
 		{ "sched",	cmd_sched,	0 },
 		{ "probe",	cmd_probe,	0 },
 		{ "kmem",	cmd_kmem,	0 },
+		{ "lock",	cmd_lock,	0 },
 	};
 	unsigned int i;
 	static const char ext[] = STRIP_EXTENSION;