[PATCH v2 10/15] perf record: manage thread specific data array

Alexey Budankov
2020-10-21T16:04:34Z

Provide allocation, initialization, finalization and releasing of
thread specific objects at thread specific data array. Allocate
thread specific object for every data buffer making one-to-one
relation between data buffer and a thread processing the buffer.
Deliver event fd related signals to thread's pollfd object.
Deliver thread control commands to ctlfd_pos fd of thread 1+.
Deliver tool external control commands via ctlfd_pos fd of thread 0.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
tools/perf/builtin-record.c | 101 ++++++++++++++++++++++++++++++++++--
1 file changed, 98 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 8e512096a060..89cb8e913fb3 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -884,6 +884,94 @@ static int record__kcore_copy(struct machine *machine, struct perf_data *data)
return kcore_copy(from_dir, kcore_dir);
}

+static int record__alloc_thread_data(struct record *rec, struct mmap *mmaps, int nr_mmaps,
+ struct fdarray *evlist_pollfd, int ctlfd_pos)
+{
+ int i, j, k, nr_thread_data;
+ struct thread_data *thread_data;
+
+ rec->nr_thread_data = nr_thread_data = nr_mmaps;
+ rec->thread_data = thread_data = zalloc(rec->nr_thread_data * sizeof(*(rec->thread_data)));
+ if (!thread_data) {
+ pr_err("Failed to allocate thread data\n");
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < nr_thread_data; i++) {
+ short revents;
+ int pos, fd;
+
+ thread_data[i].tid = -1;
+
+ if (pipe(thread_data[i].comm.msg) ||
+ pipe(thread_data[i].comm.ack)) {
+ pr_err("Failed to create thread comm pipes, errno %d\n", errno);
+ return -ENOMEM;
+ }
+
+ thread_data[i].maps = &mmaps[i];
+ thread_data[i].nr_mmaps = 1;
+
+ thread_data[i].rec = rec;
+
+ fdarray__init(&(thread_data[i].pollfd), 64);
+
+ for (j = 0; j < thread_data[i].nr_mmaps; j++) {
+ struct mmap *map = &(thread_data[i].maps[j]);
+
+ for (k = 0; k < evlist_pollfd->nr; k++) {
+ if (evlist_pollfd->priv[k].ptr != map)
+ continue;
+
+ fd = evlist_pollfd->entries[k].fd;
+ revents = evlist_pollfd->entries[k].events;
+ pos = fdarray__add(&(thread_data[i].pollfd),
+ fd, revents | POLLERR | POLLHUP,
+ fdarray_flag__default);
+ if (pos >= 0)
+ thread_data[i].pollfd.priv[pos].ptr = map;
+ else
+ return -ENOMEM;
+ }
+ }
+
+ if (i) {
+ fd = thread_data[i].comm.msg[0];
+ revents = POLLIN | POLLERR | POLLHUP;
+ } else {
+ if (ctlfd_pos == -1)
+ continue;
+ fd = evlist_pollfd->entries[ctlfd_pos].fd;
+ revents = evlist_pollfd->entries[ctlfd_pos].events;
+ }
+ thread_data[i].ctlfd_pos =
+ fdarray__add(&(thread_data[i].pollfd),
+ fd, revents, fdarray_flag__nonfilterable);
+ if (thread_data[i].ctlfd_pos < 0)
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int record__free_thread_data(struct record *rec)
+{
+ int i;
+
+ if (rec->thread_data) {
+ for (i = 0; i < rec->nr_thread_data; i++) {
+ close(rec->thread_data[i].comm.msg[0]);
+ close(rec->thread_data[i].comm.msg[1]);
+ close(rec->thread_data[i].comm.ack[0]);
+ close(rec->thread_data[i].comm.ack[1]);
+ fdarray__exit(&(rec->thread_data[i].pollfd));
+ }
+ zfree(&rec->thread_data);
+ }
+
+ return 0;
+}
+
static int record__mmap_evlist(struct record *rec,
struct evlist *evlist)
{
@@ -918,6 +1006,9 @@ static int record__mmap_evlist(struct record *rec,
}
}

+ if (evlist__initialize_ctlfd(evlist, opts->ctl_fd, opts->ctl_fd_ack))
+ return -1;
+
if (record__threads_enabled(rec)) {
int i, ret, nr = evlist->core.nr_mmaps;
struct mmap *mmaps = rec->opts.overwrite ?
@@ -929,6 +1020,12 @@ static int record__mmap_evlist(struct record *rec,

for (i = 0; i < nr; i++)
mmaps[i].file = &rec->data.dir.files[i];
+
+ ret = record__alloc_thread_data(rec, mmaps, nr,
+ &evlist->core.pollfd,
+ evlist->ctl_fd.pos);
+ if (ret)
+ return ret;
}

return 0;
@@ -1910,9 +2007,6 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
perf_evlist__start_workload(rec->evlist);
}

- if (evlist__initialize_ctlfd(rec->evlist, opts->ctl_fd, opts->ctl_fd_ack))
- goto out_child;
-
if (opts->initial_delay) {
pr_info(EVLIST_DISABLED_MSG);
if (opts->initial_delay > 0) {
@@ -2063,6 +2157,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
record__synthesize_workload(rec, true);

out_child:
+ record__free_thread_data(rec);
evlist__finalize_ctlfd(rec->evlist);
record__mmap_read_all(rec, true);
record__aio_mmap_read_sync(rec);
--
2.24.1