2021-05-04 07:06:19

by Bayduraev, Alexey V

[permalink] [raw]
Subject: [PATCH v5 03/20] perf record: introduce thread local variable

Introduce thread local variable and use it for threaded trace streaming.
Use thread affinity mask instead or record affinity mask in affinity
modes.
Introduce and use evlist__ctlfd_update() function to propagate external
control commands to global evlist object.

Acked-by: Andi Kleen <[email protected]>
Signed-off-by: Alexey Bayduraev <[email protected]>
---
tools/perf/builtin-record.c | 133 ++++++++++++++++++++++++------------
tools/perf/util/evlist.c | 16 +++++
tools/perf/util/evlist.h | 1 +
3 files changed, 106 insertions(+), 44 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index a73c28051b79..2a3dac894aa3 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -110,6 +110,8 @@ struct thread_data {
unsigned long waking;
};

+static __thread struct thread_data *thread;
+
struct record {
struct perf_tool tool;
struct record_opts opts;
@@ -132,7 +134,6 @@ struct record {
bool timestamp_boundary;
struct switch_output switch_output;
unsigned long long samples;
- struct mmap_cpu_mask affinity_mask;
unsigned long output_max_size; /* = 0: unlimited */
struct thread_mask *thread_masks;
struct thread_data *thread_data;
@@ -567,7 +568,7 @@ static int record__pushfn(struct mmap *map, void *to, void *bf, size_t size)
bf = map->data;
}

- rec->samples++;
+ thread->samples++;
return record__write(rec, map, bf, size);
}

@@ -1254,16 +1255,24 @@ static struct perf_event_header finished_round_event = {

static void record__adjust_affinity(struct record *rec, struct mmap *map)
{
+ int ret = 0;
+
if (rec->opts.affinity != PERF_AFFINITY_SYS &&
- !bitmap_equal(rec->affinity_mask.bits, map->affinity_mask.bits,
- rec->affinity_mask.nbits)) {
- bitmap_zero(rec->affinity_mask.bits, rec->affinity_mask.nbits);
- bitmap_or(rec->affinity_mask.bits, rec->affinity_mask.bits,
- map->affinity_mask.bits, rec->affinity_mask.nbits);
- sched_setaffinity(0, MMAP_CPU_MASK_BYTES(&rec->affinity_mask),
- (cpu_set_t *)rec->affinity_mask.bits);
- if (verbose == 2)
- mmap_cpu_mask__scnprintf(&rec->affinity_mask, "thread");
+ !bitmap_equal(thread->mask->affinity.bits, map->affinity_mask.bits,
+ thread->mask->affinity.nbits)) {
+ bitmap_zero(thread->mask->affinity.bits, thread->mask->affinity.nbits);
+ bitmap_or(thread->mask->affinity.bits, thread->mask->affinity.bits,
+ map->affinity_mask.bits, thread->mask->affinity.nbits);
+ ret = sched_setaffinity(0, MMAP_CPU_MASK_BYTES(&thread->mask->affinity),
+ (cpu_set_t *)thread->mask->affinity.bits);
+ if (ret)
+ pr_err("threads[%d]: sched_setaffinity() call failed: %s\n",
+ thread->tid, strerror(errno));
+ if (verbose == 2) {
+ pr_debug("threads[%d]: addr=", thread->tid);
+ mmap_cpu_mask__scnprintf(&thread->mask->affinity, "thread");
+ pr_debug("threads[%d]: on cpu=%d\n", thread->tid, sched_getcpu());
+ }
}
}

@@ -1304,14 +1313,17 @@ static int record__mmap_read_evlist(struct record *rec, struct evlist *evlist,
u64 bytes_written = rec->bytes_written;
int i;
int rc = 0;
- struct mmap *maps;
+ int nr_mmaps;
+ struct mmap **maps;
int trace_fd = rec->data.file.fd;
off_t off = 0;

if (!evlist)
return 0;

- maps = overwrite ? evlist->overwrite_mmap : evlist->mmap;
+ nr_mmaps = thread->nr_mmaps;
+ maps = overwrite ? thread->overwrite_maps : thread->maps;
+
if (!maps)
return 0;

@@ -1321,9 +1333,9 @@ static int record__mmap_read_evlist(struct record *rec, struct evlist *evlist,
if (record__aio_enabled(rec))
off = record__aio_get_pos(trace_fd);

- for (i = 0; i < evlist->core.nr_mmaps; i++) {
+ for (i = 0; i < nr_mmaps; i++) {
u64 flush = 0;
- struct mmap *map = &maps[i];
+ struct mmap *map = maps[i];

if (map->core.base) {
record__adjust_affinity(rec, map);
@@ -1386,6 +1398,15 @@ static int record__mmap_read_all(struct record *rec, bool synch)
return record__mmap_read_evlist(rec, rec->evlist, true, synch);
}

+static void record__thread_munmap_filtered(struct fdarray *fda, int fd,
+ void *arg __maybe_unused)
+{
+ struct perf_mmap *map = fda->priv[fd].ptr;
+
+ if (map)
+ perf_mmap__put(map);
+}
+
static void record__init_features(struct record *rec)
{
struct perf_session *session = rec->session;
@@ -1830,6 +1851,33 @@ static void record__uniquify_name(struct record *rec)
}
}

+static int record__start_threads(struct record *rec)
+{
+ struct thread_data *thread_data = rec->thread_data;
+
+ thread = &thread_data[0];
+
+ pr_debug("threads[%d]: started on cpu=%d\n", thread->tid, sched_getcpu());
+
+ return 0;
+}
+
+static int record__stop_threads(struct record *rec, unsigned long *waking)
+{
+ int t;
+ struct thread_data *thread_data = rec->thread_data;
+
+ for (t = 0; t < rec->nr_threads; t++) {
+ rec->samples += thread_data[t].samples;
+ *waking += thread_data[t].waking;
+ pr_debug("threads[%d]: samples=%lld, wakes=%ld, trasferred=%ld, compressed=%ld\n",
+ thread_data[t].tid, thread_data[t].samples, thread_data[t].waking,
+ rec->session->bytes_transferred, rec->session->bytes_compressed);
+ }
+
+ return 0;
+}
+
static int __cmd_record(struct record *rec, int argc, const char **argv)
{
int err;
@@ -1938,7 +1986,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)

if (record__open(rec) != 0) {
err = -1;
- goto out_child;
+ goto out_free_threads;
}
session->header.env.comp_mmap_len = session->evlist->core.mmap_len;

@@ -1946,7 +1994,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
err = record__kcore_copy(&session->machines.host, data);
if (err) {
pr_err("ERROR: Failed to copy kcore\n");
- goto out_child;
+ goto out_free_threads;
}
}

@@ -1957,7 +2005,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
bpf__strerror_apply_obj_config(err, errbuf, sizeof(errbuf));
pr_err("ERROR: Apply config to BPF failed: %s\n",
errbuf);
- goto out_child;
+ goto out_free_threads;
}

/*
@@ -1975,11 +2023,11 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
if (data->is_pipe) {
err = perf_header__write_pipe(fd);
if (err < 0)
- goto out_child;
+ goto out_free_threads;
} else {
err = perf_session__write_header(session, rec->evlist, fd, false);
if (err < 0)
- goto out_child;
+ goto out_free_threads;
}

err = -1;
@@ -1987,16 +2035,16 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
&& !perf_header__has_feat(&session->header, HEADER_BUILD_ID)) {
pr_err("Couldn't generate buildids. "
"Use --no-buildid to profile anyway.\n");
- goto out_child;
+ goto out_free_threads;
}

err = record__setup_sb_evlist(rec);
if (err)
- goto out_child;
+ goto out_free_threads;

err = record__synthesize(rec, false);
if (err < 0)
- goto out_child;
+ goto out_free_threads;

if (rec->realtime_prio) {
struct sched_param param;
@@ -2005,10 +2053,13 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
if (sched_setscheduler(0, SCHED_FIFO, &param)) {
pr_err("Could not set realtime priority.\n");
err = -1;
- goto out_child;
+ goto out_free_threads;
}
}

+ if (record__start_threads(rec))
+ goto out_free_threads;
+
/*
* When perf is starting the traced process, all the events
* (apart from group members) have enable_on_exec=1 set,
@@ -2079,7 +2130,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
trigger_ready(&switch_output_trigger);
perf_hooks__invoke_record_start();
for (;;) {
- unsigned long long hits = rec->samples;
+ unsigned long long hits = thread->samples;

/*
* rec->evlist->bkw_mmap_state is possible to be
@@ -2148,20 +2199,24 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
alarm(rec->switch_output.time);
}

- if (hits == rec->samples) {
+ if (hits == thread->samples) {
if (done || draining)
break;
- err = evlist__poll(rec->evlist, -1);
+ err = fdarray__poll(&thread->pollfd, -1);
/*
* Propagate error, only if there's any. Ignore positive
* number of returned events and interrupt error.
*/
if (err > 0 || (err < 0 && errno == EINTR))
err = 0;
- waking++;
+ thread->waking++;

- if (evlist__filter_pollfd(rec->evlist, POLLERR | POLLHUP) == 0)
+ if (fdarray__filter(&thread->pollfd, POLLERR | POLLHUP,
+ record__thread_munmap_filtered, NULL) == 0)
draining = true;
+
+ evlist__ctlfd_update(rec->evlist,
+ &thread->pollfd.entries[thread->ctlfd_pos]);
}

if (evlist__ctlfd_process(rec->evlist, &cmd) > 0) {
@@ -2214,18 +2269,20 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
goto out_child;
}

- if (!quiet)
- fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
-
if (target__none(&rec->opts.target))
record__synthesize_workload(rec, true);

out_child:
+ record__stop_threads(rec, &waking);
+out_free_threads:
record__free_thread_data(rec);
evlist__finalize_ctlfd(rec->evlist);
record__mmap_read_all(rec, true);
record__aio_mmap_read_sync(rec);

+ if (!quiet)
+ fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
+
if (rec->session->bytes_transferred && rec->session->bytes_compressed) {
ratio = (float)rec->session->bytes_transferred/(float)rec->session->bytes_compressed;
session->header.env.comp_ratio = ratio + 0.5;
@@ -3058,17 +3115,6 @@ int cmd_record(int argc, const char **argv)

symbol__init(NULL);

- if (rec->opts.affinity != PERF_AFFINITY_SYS) {
- rec->affinity_mask.nbits = cpu__max_cpu();
- rec->affinity_mask.bits = bitmap_alloc(rec->affinity_mask.nbits);
- if (!rec->affinity_mask.bits) {
- pr_err("Failed to allocate thread mask for %zd cpus\n", rec->affinity_mask.nbits);
- err = -ENOMEM;
- goto out_opts;
- }
- pr_debug2("thread mask[%zd]: empty\n", rec->affinity_mask.nbits);
- }
-
err = record__auxtrace_init(rec);
if (err)
goto out;
@@ -3206,7 +3252,6 @@ int cmd_record(int argc, const char **argv)

err = __cmd_record(&record, argc, argv);
out:
- bitmap_free(rec->affinity_mask.bits);
evlist__delete(rec->evlist);
symbol__exit();
auxtrace_record__free(rec->itr);
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 6e5c41528c7d..ac343a42408d 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -2135,6 +2135,22 @@ int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd)
return err;
}

+int evlist__ctlfd_update(struct evlist *evlist, struct pollfd *update)
+{
+ int ctlfd_pos = evlist->ctl_fd.pos;
+ struct pollfd *entries = evlist->core.pollfd.entries;
+
+ if (!evlist__ctlfd_initialized(evlist))
+ return 0;
+
+ if (entries[ctlfd_pos].fd != update->fd ||
+ entries[ctlfd_pos].events != update->events)
+ return -1;
+
+ entries[ctlfd_pos].revents = update->revents;
+ return 0;
+}
+
struct evsel *evlist__find_evsel(struct evlist *evlist, int idx)
{
struct evsel *evsel;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index a8b97b50cceb..f3d96e79f667 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -358,6 +358,7 @@ void evlist__close_control(int ctl_fd, int ctl_fd_ack, bool *ctl_fd_close);
int evlist__initialize_ctlfd(struct evlist *evlist, int ctl_fd, int ctl_fd_ack);
int evlist__finalize_ctlfd(struct evlist *evlist);
bool evlist__ctlfd_initialized(struct evlist *evlist);
+int evlist__ctlfd_update(struct evlist *evlist, struct pollfd *update);
int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd);
int evlist__ctlfd_ack(struct evlist *evlist);

--
2.19.0