Re: [PATCH v12 05/16] perf record: Introduce thread local variable

Jiri Olsa
2021-12-05T15:14:46Z

On Tue, Nov 23, 2021 at 05:08:01PM +0300, Alexey Bayduraev wrote:

SNIP

>
> + 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,
> @@ -2122,7 +2175,7 @@ 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
> @@ -2176,8 +2229,8 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
>
> if (!quiet)
> fprintf(stderr, "[ perf record: dump data: Woken up %ld times ]\n",
> - waking);
> - waking = 0;
> + record__waking(rec));
> + thread->waking = 0;
> fd = record__switch_output(rec, false);
> if (fd < 0) {
> pr_err("Failed to switch to new file\n");
> @@ -2191,20 +2244,24 @@ 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]);

hm, why is this needed? we only switch to record_thread data, right?
there should not be any processing change

jirka

> }
>
> if (evlist__ctlfd_process(rec->evlist, &cmd) > 0) {
> @@ -2258,15 +2315,18 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
> }
>
> if (!quiet)
> - fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
> + fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n",
> + record__waking(rec));
>
> if (target__none(&rec->opts.target))
> record__synthesize_workload(rec, true);
>
> out_child:
> - evlist__finalize_ctlfd(rec->evlist);
> + record__stop_threads(rec);
> record__mmap_read_all(rec, true);
> +out_free_threads:
> record__free_thread_data(rec);
> + evlist__finalize_ctlfd(rec->evlist);
> record__aio_mmap_read_sync(rec);
>
> if (rec->session->bytes_transferred && rec->session->bytes_compressed) {
> @@ -3158,17 +3218,6 @@ 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_zalloc(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;
> @@ -3313,7 +3362,6 @@ 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);
> --
> 2.19.0
>