kernel_optimize_test/tools/perf/builtin-lock.c
Frederic Weisbecker b67577dfb4 perf lock: Drop the buffers multiplexing dependency
We need to deal with time ordered events to build a correct
state machine of lock events. This is why we multiplex the lock
events buffers. But the ordering is done from the kernel, on
the tracing fast path, leading to high contention between cpus.

Without multiplexing, the events appears in a weak order.
If we have four events, each split per cpu, perf record will
read the events buffers in the following order:

[ CPU0 ev0, CPU0 ev1, CPU0 ev3, CPU0 ev4, CPU1 ev0, CPU1 ev0....]

To handle a post processing reordering, we could just read and sort
the whole in memory, but it just doesn't scale with high amounts
of events: lock events can fill huge amounts in few times.

Basically we need to sort in memory and find a "grace period"
point when we know that a given slice of previously sorted events
can be committed for post-processing, so that we can unload the
memory usage step by step and keep a scalable sorting list.

There is no strong rules about how to define such "grace period".
What does this patch is:

We define a FLUSH_PERIOD value that defines a grace period in
seconds.
We want to have a slice of events covering 2 * FLUSH_PERIOD in our
sorted list.
If FLUSH_PERIOD is big enough, it ensures every events that occured
in the first half of the timeslice have all been buffered and there
are none remaining and there won't be further to put inside this
first timeslice. Then once we reach the 2 * FLUSH_PERIOD
timeslice, we flush the first half to be gentle with the memory
(the second half can still get new events in the middle, so wait
another period to flush it)

FLUSH_PERIOD is defined to 5 seconds. Say the first event started on
time t0. We can safely assume that at the time we are processing
events of t0 + 10 seconds, ther won't be anymore events to read
from perf.data that occured between t0 and t0 + 5 seconds. Hence
we can safely flush the first half.

To point out funky bugs, we have a guardian that checks a new event
timestamp is not below the last event's timestamp flushed and that
displays a warning in this case.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
2010-02-27 17:06:19 +01:00

823 lines
19 KiB
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 */
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 *);
static struct rb_root result; /* place to store sorted data */
#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 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)
{
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);
/* 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;
};
struct trace_acquired_event {
void *addr;
const char *name;
};
struct trace_contended_event {
void *addr;
const char *name;
};
struct trace_release_event {
void *addr;
const char *name;
};
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
report_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);
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
report_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);
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
report_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);
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
report_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);
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 report_lock_ops = {
.acquire_event = report_lock_acquire_event,
.acquired_event = report_lock_acquired_event,
.contended_event = report_lock_contended_event,
.release_event = report_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);
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);
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);
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);
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);
}
struct raw_event_queue {
u64 timestamp;
int cpu;
void *data;
struct thread *thread;
struct list_head list;
};
static LIST_HEAD(raw_event_head);
#define FLUSH_PERIOD (5 * NSEC_PER_SEC)
static u64 flush_limit = ULLONG_MAX;
static u64 last_flush = 0;
struct raw_event_queue *last_inserted;
static void flush_raw_event_queue(u64 limit)
{
struct raw_event_queue *tmp, *iter;
list_for_each_entry_safe(iter, tmp, &raw_event_head, list) {
if (iter->timestamp > limit)
return;
if (iter == last_inserted)
last_inserted = NULL;
process_raw_event(iter->data, iter->cpu, iter->timestamp,
iter->thread);
last_flush = iter->timestamp;
list_del(&iter->list);
free(iter->data);
free(iter);
}
}
static void __queue_raw_event_end(struct raw_event_queue *new)
{
struct raw_event_queue *iter;
list_for_each_entry_reverse(iter, &raw_event_head, list) {
if (iter->timestamp < new->timestamp) {
list_add(&new->list, &iter->list);
return;
}
}
list_add(&new->list, &raw_event_head);
}
static void __queue_raw_event_before(struct raw_event_queue *new,
struct raw_event_queue *iter)
{
list_for_each_entry_continue_reverse(iter, &raw_event_head, list) {
if (iter->timestamp < new->timestamp) {
list_add(&new->list, &iter->list);
return;
}
}
list_add(&new->list, &raw_event_head);
}
static void __queue_raw_event_after(struct raw_event_queue *new,
struct raw_event_queue *iter)
{
list_for_each_entry_continue(iter, &raw_event_head, list) {
if (iter->timestamp > new->timestamp) {
list_add_tail(&new->list, &iter->list);
return;
}
}
list_add_tail(&new->list, &raw_event_head);
}
/* The queue is ordered by time */
static void __queue_raw_event(struct raw_event_queue *new)
{
if (!last_inserted) {
__queue_raw_event_end(new);
return;
}
/*
* Most of the time the current event has a timestamp
* very close to the last event inserted, unless we just switched
* to another event buffer. Having a sorting based on a list and
* on the last inserted event that is close to the current one is
* probably more efficient than an rbtree based sorting.
*/
if (last_inserted->timestamp >= new->timestamp)
__queue_raw_event_before(new, last_inserted);
else
__queue_raw_event_after(new, last_inserted);
}
static void queue_raw_event(void *data, int raw_size, int cpu,
u64 timestamp, struct thread *thread)
{
struct raw_event_queue *new;
if (flush_limit == ULLONG_MAX)
flush_limit = timestamp + FLUSH_PERIOD;
if (timestamp < last_flush) {
printf("Warning: Timestamp below last timeslice flush\n");
return;
}
new = malloc(sizeof(*new));
if (!new)
die("Not enough memory\n");
new->timestamp = timestamp;
new->cpu = cpu;
new->thread = thread;
new->data = malloc(raw_size);
if (!new->data)
die("Not enough memory\n");
memcpy(new->data, data, raw_size);
__queue_raw_event(new);
last_inserted = new;
/*
* We want to have a slice of events covering 2 * FLUSH_PERIOD
* If FLUSH_PERIOD is big enough, it ensures every events that occured
* in the first half of the timeslice have all been buffered and there
* are none remaining (we need that because of the weakly ordered
* event recording we have). Then once we reach the 2 * FLUSH_PERIOD
* timeslice, we flush the first half to be gentle with the memory
* (the second half can still get new events in the middle, so wait
* another period to flush it)
*/
if (new->timestamp > flush_limit &&
new->timestamp - flush_limit > FLUSH_PERIOD) {
flush_limit += FLUSH_PERIOD;
flush_raw_event_queue(flush_limit);
}
}
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);
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;
queue_raw_event(data.raw_data, data.raw_size, 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\n", st->addr, st->name);
}
}
}
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_report(void)
{
setup_pager();
select_key();
read_events();
flush_raw_event_queue(ULLONG_MAX);
sort_result();
print_result();
}
static const char * const report_usage[] = {
"perf lock report [<options>]",
NULL
};
static const struct option report_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|report}",
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",
"-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], "report", 6)) {
trace_handler = &report_lock_ops;
if (argc) {
argc = parse_options(argc, argv,
report_options, report_usage, 0);
if (argc)
usage_with_options(report_usage, report_options);
}
__cmd_report();
} else if (!strcmp(argv[0], "trace")) {
/* Aliased to 'perf trace' */
return cmd_trace(argc, argv, prefix);
} else if (!strcmp(argv[0], "map")) {
/* recycling report_lock_ops */
trace_handler = &report_lock_ops;
setup_pager();
read_events();
dump_map();
} else {
usage_with_options(lock_usage, lock_options);
}
return 0;
}