Revision cd4d4fc4137502f88ee871fc015a934dc28535e3 authored by Linus Torvalds on 07 September 2010, 21:08:17 UTC, committed by Linus Torvalds on 07 September 2010, 21:08:17 UTC
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: use zalloc_cpumask_var() for gcwq->mayday_mask workqueue: fix GCWQ_DISASSOCIATED initialization workqueue: Add a workqueue chapter to the tracepoint docbook workqueue: fix cwq->nr_active underflow workqueue: improve destroy_workqueue() debuggability workqueue: mark lock acquisition on worker_maybe_bind_and_lock() workqueue: annotate lock context change workqueue: free rescuer on destroy_workqueue
builtin-record.c
/*
* builtin-record.c
*
* Builtin record command: Record the profile of a workload
* (or a CPU, or a PID) into the perf.data output file - for
* later analysis via perf report.
*/
#define _FILE_OFFSET_BITS 64
#include "builtin.h"
#include "perf.h"
#include "util/build-id.h"
#include "util/util.h"
#include "util/parse-options.h"
#include "util/parse-events.h"
#include "util/header.h"
#include "util/event.h"
#include "util/debug.h"
#include "util/session.h"
#include "util/symbol.h"
#include "util/cpumap.h"
#include <unistd.h>
#include <sched.h>
#include <sys/mman.h>
enum write_mode_t {
WRITE_FORCE,
WRITE_APPEND
};
static int *fd[MAX_NR_CPUS][MAX_COUNTERS];
static u64 user_interval = ULLONG_MAX;
static u64 default_interval = 0;
static int nr_cpus = 0;
static unsigned int page_size;
static unsigned int mmap_pages = 128;
static unsigned int user_freq = UINT_MAX;
static int freq = 1000;
static int output;
static int pipe_output = 0;
static const char *output_name = "perf.data";
static int group = 0;
static int realtime_prio = 0;
static bool raw_samples = false;
static bool system_wide = false;
static pid_t target_pid = -1;
static pid_t target_tid = -1;
static pid_t *all_tids = NULL;
static int thread_num = 0;
static pid_t child_pid = -1;
static bool no_inherit = false;
static enum write_mode_t write_mode = WRITE_FORCE;
static bool call_graph = false;
static bool inherit_stat = false;
static bool no_samples = false;
static bool sample_address = false;
static bool no_buildid = false;
static long samples = 0;
static u64 bytes_written = 0;
static struct pollfd *event_array;
static int nr_poll = 0;
static int nr_cpu = 0;
static int file_new = 1;
static off_t post_processing_offset;
static struct perf_session *session;
static const char *cpu_list;
struct mmap_data {
int counter;
void *base;
unsigned int mask;
unsigned int prev;
};
static struct mmap_data mmap_array[MAX_NR_CPUS];
static unsigned long mmap_read_head(struct mmap_data *md)
{
struct perf_event_mmap_page *pc = md->base;
long head;
head = pc->data_head;
rmb();
return head;
}
static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
{
struct perf_event_mmap_page *pc = md->base;
/*
* ensure all reads are done before we write the tail out.
*/
/* mb(); */
pc->data_tail = tail;
}
static void advance_output(size_t size)
{
bytes_written += size;
}
static void write_output(void *buf, size_t size)
{
while (size) {
int ret = write(output, buf, size);
if (ret < 0)
die("failed to write");
size -= ret;
buf += ret;
bytes_written += ret;
}
}
static int process_synthesized_event(event_t *event,
struct perf_session *self __used)
{
write_output(event, event->header.size);
return 0;
}
static void mmap_read(struct mmap_data *md)
{
unsigned int head = mmap_read_head(md);
unsigned int old = md->prev;
unsigned char *data = md->base + page_size;
unsigned long size;
void *buf;
int diff;
/*
* If we're further behind than half the buffer, there's a chance
* the writer will bite our tail and mess up the samples under us.
*
* If we somehow ended up ahead of the head, we got messed up.
*
* In either case, truncate and restart at head.
*/
diff = head - old;
if (diff < 0) {
fprintf(stderr, "WARNING: failed to keep up with mmap data\n");
/*
* head points to a known good entry, start there.
*/
old = head;
}
if (old != head)
samples++;
size = head - old;
if ((old & md->mask) + size != (head & md->mask)) {
buf = &data[old & md->mask];
size = md->mask + 1 - (old & md->mask);
old += size;
write_output(buf, size);
}
buf = &data[old & md->mask];
size = head - old;
old += size;
write_output(buf, size);
md->prev = old;
mmap_write_tail(md, old);
}
static volatile int done = 0;
static volatile int signr = -1;
static void sig_handler(int sig)
{
done = 1;
signr = sig;
}
static void sig_atexit(void)
{
if (child_pid > 0)
kill(child_pid, SIGTERM);
if (signr == -1)
return;
signal(signr, SIG_DFL);
kill(getpid(), signr);
}
static int group_fd;
static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
{
struct perf_header_attr *h_attr;
if (nr < session->header.attrs) {
h_attr = session->header.attr[nr];
} else {
h_attr = perf_header_attr__new(a);
if (h_attr != NULL)
if (perf_header__add_attr(&session->header, h_attr) < 0) {
perf_header_attr__delete(h_attr);
h_attr = NULL;
}
}
return h_attr;
}
static void create_counter(int counter, int cpu)
{
char *filter = filters[counter];
struct perf_event_attr *attr = attrs + counter;
struct perf_header_attr *h_attr;
int track = !counter; /* only the first counter needs these */
int thread_index;
int ret;
struct {
u64 count;
u64 time_enabled;
u64 time_running;
u64 id;
} read_data;
attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
PERF_FORMAT_TOTAL_TIME_RUNNING |
PERF_FORMAT_ID;
attr->sample_type |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
if (nr_counters > 1)
attr->sample_type |= PERF_SAMPLE_ID;
/*
* We default some events to a 1 default interval. But keep
* it a weak assumption overridable by the user.
*/
if (!attr->sample_period || (user_freq != UINT_MAX &&
user_interval != ULLONG_MAX)) {
if (freq) {
attr->sample_type |= PERF_SAMPLE_PERIOD;
attr->freq = 1;
attr->sample_freq = freq;
} else {
attr->sample_period = default_interval;
}
}
if (no_samples)
attr->sample_freq = 0;
if (inherit_stat)
attr->inherit_stat = 1;
if (sample_address) {
attr->sample_type |= PERF_SAMPLE_ADDR;
attr->mmap_data = track;
}
if (call_graph)
attr->sample_type |= PERF_SAMPLE_CALLCHAIN;
if (system_wide)
attr->sample_type |= PERF_SAMPLE_CPU;
if (raw_samples) {
attr->sample_type |= PERF_SAMPLE_TIME;
attr->sample_type |= PERF_SAMPLE_RAW;
attr->sample_type |= PERF_SAMPLE_CPU;
}
attr->mmap = track;
attr->comm = track;
attr->inherit = !no_inherit;
if (target_pid == -1 && target_tid == -1 && !system_wide) {
attr->disabled = 1;
attr->enable_on_exec = 1;
}
for (thread_index = 0; thread_index < thread_num; thread_index++) {
try_again:
fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr,
all_tids[thread_index], cpu, group_fd, 0);
if (fd[nr_cpu][counter][thread_index] < 0) {
int err = errno;
if (err == EPERM || err == EACCES)
die("Permission error - are you root?\n"
"\t Consider tweaking"
" /proc/sys/kernel/perf_event_paranoid.\n");
else if (err == ENODEV && cpu_list) {
die("No such device - did you specify"
" an out-of-range profile CPU?\n");
}
/*
* If it's cycles then fall back to hrtimer
* based cpu-clock-tick sw counter, which
* is always available even if no PMU support:
*/
if (attr->type == PERF_TYPE_HARDWARE
&& attr->config == PERF_COUNT_HW_CPU_CYCLES) {
if (verbose)
warning(" ... trying to fall back to cpu-clock-ticks\n");
attr->type = PERF_TYPE_SOFTWARE;
attr->config = PERF_COUNT_SW_CPU_CLOCK;
goto try_again;
}
printf("\n");
error("perfcounter syscall returned with %d (%s)\n",
fd[nr_cpu][counter][thread_index], strerror(err));
#if defined(__i386__) || defined(__x86_64__)
if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
die("No hardware sampling interrupt available."
" No APIC? If so then you can boot the kernel"
" with the \"lapic\" boot parameter to"
" force-enable it.\n");
#endif
die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
exit(-1);
}
h_attr = get_header_attr(attr, counter);
if (h_attr == NULL)
die("nomem\n");
if (!file_new) {
if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
fprintf(stderr, "incompatible append\n");
exit(-1);
}
}
if (read(fd[nr_cpu][counter][thread_index], &read_data, sizeof(read_data)) == -1) {
perror("Unable to read perf file descriptor\n");
exit(-1);
}
if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
pr_warning("Not enough memory to add id\n");
exit(-1);
}
assert(fd[nr_cpu][counter][thread_index] >= 0);
fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK);
/*
* First counter acts as the group leader:
*/
if (group && group_fd == -1)
group_fd = fd[nr_cpu][counter][thread_index];
if (counter || thread_index) {
ret = ioctl(fd[nr_cpu][counter][thread_index],
PERF_EVENT_IOC_SET_OUTPUT,
fd[nr_cpu][0][0]);
if (ret) {
error("failed to set output: %d (%s)\n", errno,
strerror(errno));
exit(-1);
}
} else {
mmap_array[nr_cpu].counter = counter;
mmap_array[nr_cpu].prev = 0;
mmap_array[nr_cpu].mask = mmap_pages*page_size - 1;
mmap_array[nr_cpu].base = mmap(NULL, (mmap_pages+1)*page_size,
PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter][thread_index], 0);
if (mmap_array[nr_cpu].base == MAP_FAILED) {
error("failed to mmap with %d (%s)\n", errno, strerror(errno));
exit(-1);
}
event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index];
event_array[nr_poll].events = POLLIN;
nr_poll++;
}
if (filter != NULL) {
ret = ioctl(fd[nr_cpu][counter][thread_index],
PERF_EVENT_IOC_SET_FILTER, filter);
if (ret) {
error("failed to set filter with %d (%s)\n", errno,
strerror(errno));
exit(-1);
}
}
}
}
static void open_counters(int cpu)
{
int counter;
group_fd = -1;
for (counter = 0; counter < nr_counters; counter++)
create_counter(counter, cpu);
nr_cpu++;
}
static int process_buildids(void)
{
u64 size = lseek(output, 0, SEEK_CUR);
if (size == 0)
return 0;
session->fd = output;
return __perf_session__process_events(session, post_processing_offset,
size - post_processing_offset,
size, &build_id__mark_dso_hit_ops);
}
static void atexit_header(void)
{
if (!pipe_output) {
session->header.data_size += bytes_written;
process_buildids();
perf_header__write(&session->header, output, true);
perf_session__delete(session);
symbol__exit();
}
}
static void event__synthesize_guest_os(struct machine *machine, void *data)
{
int err;
struct perf_session *psession = data;
if (machine__is_host(machine))
return;
/*
*As for guest kernel when processing subcommand record&report,
*we arrange module mmap prior to guest kernel mmap and trigger
*a preload dso because default guest module symbols are loaded
*from guest kallsyms instead of /lib/modules/XXX/XXX. This
*method is used to avoid symbol missing when the first addr is
*in module instead of in guest kernel.
*/
err = event__synthesize_modules(process_synthesized_event,
psession, machine);
if (err < 0)
pr_err("Couldn't record guest kernel [%d]'s reference"
" relocation symbol.\n", machine->pid);
/*
* We use _stext for guest kernel because guest kernel's /proc/kallsyms
* have no _text sometimes.
*/
err = event__synthesize_kernel_mmap(process_synthesized_event,
psession, machine, "_text");
if (err < 0)
err = event__synthesize_kernel_mmap(process_synthesized_event,
psession, machine, "_stext");
if (err < 0)
pr_err("Couldn't record guest kernel [%d]'s reference"
" relocation symbol.\n", machine->pid);
}
static struct perf_event_header finished_round_event = {
.size = sizeof(struct perf_event_header),
.type = PERF_RECORD_FINISHED_ROUND,
};
static void mmap_read_all(void)
{
int i;
for (i = 0; i < nr_cpu; i++) {
if (mmap_array[i].base)
mmap_read(&mmap_array[i]);
}
if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
write_output(&finished_round_event, sizeof(finished_round_event));
}
static int __cmd_record(int argc, const char **argv)
{
int i, counter;
struct stat st;
int flags;
int err;
unsigned long waking = 0;
int child_ready_pipe[2], go_pipe[2];
const bool forks = argc > 0;
char buf;
struct machine *machine;
page_size = sysconf(_SC_PAGE_SIZE);
atexit(sig_atexit);
signal(SIGCHLD, sig_handler);
signal(SIGINT, sig_handler);
if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
perror("failed to create pipes");
exit(-1);
}
if (!strcmp(output_name, "-"))
pipe_output = 1;
else if (!stat(output_name, &st) && st.st_size) {
if (write_mode == WRITE_FORCE) {
char oldname[PATH_MAX];
snprintf(oldname, sizeof(oldname), "%s.old",
output_name);
unlink(oldname);
rename(output_name, oldname);
}
} else if (write_mode == WRITE_APPEND) {
write_mode = WRITE_FORCE;
}
flags = O_CREAT|O_RDWR;
if (write_mode == WRITE_APPEND)
file_new = 0;
else
flags |= O_TRUNC;
if (pipe_output)
output = STDOUT_FILENO;
else
output = open(output_name, flags, S_IRUSR | S_IWUSR);
if (output < 0) {
perror("failed to create output file");
exit(-1);
}
session = perf_session__new(output_name, O_WRONLY,
write_mode == WRITE_FORCE, false);
if (session == NULL) {
pr_err("Not enough memory for reading perf file header\n");
return -1;
}
if (!file_new) {
err = perf_header__read(session, output);
if (err < 0)
goto out_delete_session;
}
if (have_tracepoints(attrs, nr_counters))
perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
/*
* perf_session__delete(session) will be called at atexit_header()
*/
atexit(atexit_header);
if (forks) {
child_pid = fork();
if (child_pid < 0) {
perror("failed to fork");
exit(-1);
}
if (!child_pid) {
if (pipe_output)
dup2(2, 1);
close(child_ready_pipe[0]);
close(go_pipe[1]);
fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
/*
* Do a dummy execvp to get the PLT entry resolved,
* so we avoid the resolver overhead on the real
* execvp call.
*/
execvp("", (char **)argv);
/*
* Tell the parent we're ready to go
*/
close(child_ready_pipe[1]);
/*
* Wait until the parent tells us to go.
*/
if (read(go_pipe[0], &buf, 1) == -1)
perror("unable to read pipe");
execvp(argv[0], (char **)argv);
perror(argv[0]);
exit(-1);
}
if (!system_wide && target_tid == -1 && target_pid == -1)
all_tids[0] = child_pid;
close(child_ready_pipe[1]);
close(go_pipe[0]);
/*
* wait for child to settle
*/
if (read(child_ready_pipe[0], &buf, 1) == -1) {
perror("unable to read pipe");
exit(-1);
}
close(child_ready_pipe[0]);
}
nr_cpus = read_cpu_map(cpu_list);
if (nr_cpus < 1) {
perror("failed to collect number of CPUs\n");
return -1;
}
if (!system_wide && no_inherit && !cpu_list) {
open_counters(-1);
} else {
for (i = 0; i < nr_cpus; i++)
open_counters(cpumap[i]);
}
if (pipe_output) {
err = perf_header__write_pipe(output);
if (err < 0)
return err;
} else if (file_new) {
err = perf_header__write(&session->header, output, false);
if (err < 0)
return err;
}
post_processing_offset = lseek(output, 0, SEEK_CUR);
if (pipe_output) {
err = event__synthesize_attrs(&session->header,
process_synthesized_event,
session);
if (err < 0) {
pr_err("Couldn't synthesize attrs.\n");
return err;
}
err = event__synthesize_event_types(process_synthesized_event,
session);
if (err < 0) {
pr_err("Couldn't synthesize event_types.\n");
return err;
}
if (have_tracepoints(attrs, nr_counters)) {
/*
* FIXME err <= 0 here actually means that
* there were no tracepoints so its not really
* an error, just that we don't need to
* synthesize anything. We really have to
* return this more properly and also
* propagate errors that now are calling die()
*/
err = event__synthesize_tracing_data(output, attrs,
nr_counters,
process_synthesized_event,
session);
if (err <= 0) {
pr_err("Couldn't record tracing data.\n");
return err;
}
advance_output(err);
}
}
machine = perf_session__find_host_machine(session);
if (!machine) {
pr_err("Couldn't find native kernel information.\n");
return -1;
}
err = event__synthesize_kernel_mmap(process_synthesized_event,
session, machine, "_text");
if (err < 0)
err = event__synthesize_kernel_mmap(process_synthesized_event,
session, machine, "_stext");
if (err < 0) {
pr_err("Couldn't record kernel reference relocation symbol.\n");
return err;
}
err = event__synthesize_modules(process_synthesized_event,
session, machine);
if (err < 0) {
pr_err("Couldn't record kernel reference relocation symbol.\n");
return err;
}
if (perf_guest)
perf_session__process_machines(session, event__synthesize_guest_os);
if (!system_wide)
event__synthesize_thread(target_tid, process_synthesized_event,
session);
else
event__synthesize_threads(process_synthesized_event, session);
if (realtime_prio) {
struct sched_param param;
param.sched_priority = realtime_prio;
if (sched_setscheduler(0, SCHED_FIFO, ¶m)) {
pr_err("Could not set realtime priority.\n");
exit(-1);
}
}
/*
* Let the child rip
*/
if (forks)
close(go_pipe[1]);
for (;;) {
int hits = samples;
int thread;
mmap_read_all();
if (hits == samples) {
if (done)
break;
err = poll(event_array, nr_poll, -1);
waking++;
}
if (done) {
for (i = 0; i < nr_cpu; i++) {
for (counter = 0;
counter < nr_counters;
counter++) {
for (thread = 0;
thread < thread_num;
thread++)
ioctl(fd[i][counter][thread],
PERF_EVENT_IOC_DISABLE);
}
}
}
}
fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
/*
* Approximate RIP event size: 24 bytes.
*/
fprintf(stderr,
"[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
(double)bytes_written / 1024.0 / 1024.0,
output_name,
bytes_written / 24);
return 0;
out_delete_session:
perf_session__delete(session);
return err;
}
static const char * const record_usage[] = {
"perf record [<options>] [<command>]",
"perf record [<options>] -- <command> [<options>]",
NULL
};
static bool force, append_file;
static const struct option options[] = {
OPT_CALLBACK('e', "event", NULL, "event",
"event selector. use 'perf list' to list available events",
parse_events),
OPT_CALLBACK(0, "filter", NULL, "filter",
"event filter", parse_filter),
OPT_INTEGER('p', "pid", &target_pid,
"record events on existing process id"),
OPT_INTEGER('t', "tid", &target_tid,
"record events on existing thread id"),
OPT_INTEGER('r', "realtime", &realtime_prio,
"collect data with this RT SCHED_FIFO priority"),
OPT_BOOLEAN('R', "raw-samples", &raw_samples,
"collect raw sample records from all opened counters"),
OPT_BOOLEAN('a', "all-cpus", &system_wide,
"system-wide collection from all CPUs"),
OPT_BOOLEAN('A', "append", &append_file,
"append to the output file to do incremental profiling"),
OPT_STRING('C', "cpu", &cpu_list, "cpu",
"list of cpus to monitor"),
OPT_BOOLEAN('f', "force", &force,
"overwrite existing data file (deprecated)"),
OPT_U64('c', "count", &user_interval, "event period to sample"),
OPT_STRING('o', "output", &output_name, "file",
"output file name"),
OPT_BOOLEAN('i', "no-inherit", &no_inherit,
"child tasks do not inherit counters"),
OPT_UINTEGER('F', "freq", &user_freq, "profile at this frequency"),
OPT_UINTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"),
OPT_BOOLEAN('g', "call-graph", &call_graph,
"do call-graph (stack chain/backtrace) recording"),
OPT_INCR('v', "verbose", &verbose,
"be more verbose (show counter open errors, etc)"),
OPT_BOOLEAN('s', "stat", &inherit_stat,
"per thread counts"),
OPT_BOOLEAN('d', "data", &sample_address,
"Sample addresses"),
OPT_BOOLEAN('n', "no-samples", &no_samples,
"don't sample"),
OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid,
"do not update the buildid cache"),
OPT_END()
};
int cmd_record(int argc, const char **argv, const char *prefix __used)
{
int i, j, err = -ENOMEM;
argc = parse_options(argc, argv, options, record_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
if (!argc && target_pid == -1 && target_tid == -1 &&
!system_wide && !cpu_list)
usage_with_options(record_usage, options);
if (force && append_file) {
fprintf(stderr, "Can't overwrite and append at the same time."
" You need to choose between -f and -A");
usage_with_options(record_usage, options);
} else if (append_file) {
write_mode = WRITE_APPEND;
} else {
write_mode = WRITE_FORCE;
}
symbol__init();
if (no_buildid)
disable_buildid_cache();
if (!nr_counters) {
nr_counters = 1;
attrs[0].type = PERF_TYPE_HARDWARE;
attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
}
if (target_pid != -1) {
target_tid = target_pid;
thread_num = find_all_tid(target_pid, &all_tids);
if (thread_num <= 0) {
fprintf(stderr, "Can't find all threads of pid %d\n",
target_pid);
usage_with_options(record_usage, options);
}
} else {
all_tids=malloc(sizeof(pid_t));
if (!all_tids)
goto out_symbol_exit;
all_tids[0] = target_tid;
thread_num = 1;
}
for (i = 0; i < MAX_NR_CPUS; i++) {
for (j = 0; j < MAX_COUNTERS; j++) {
fd[i][j] = malloc(sizeof(int)*thread_num);
if (!fd[i][j])
goto out_free_fd;
}
}
event_array = malloc(
sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
if (!event_array)
goto out_free_fd;
if (user_interval != ULLONG_MAX)
default_interval = user_interval;
if (user_freq != UINT_MAX)
freq = user_freq;
/*
* User specified count overrides default frequency.
*/
if (default_interval)
freq = 0;
else if (freq) {
default_interval = freq;
} else {
fprintf(stderr, "frequency and count are zero, aborting\n");
err = -EINVAL;
goto out_free_event_array;
}
err = __cmd_record(argc, argv);
out_free_event_array:
free(event_array);
out_free_fd:
for (i = 0; i < MAX_NR_CPUS; i++) {
for (j = 0; j < MAX_COUNTERS; j++)
free(fd[i][j]);
}
free(all_tids);
all_tids = NULL;
out_symbol_exit:
symbol__exit();
return err;
}
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...