[PATCH 03/21] perf db-export: Pass main_thread to db_export__thread()

Adrian Hunter
2019-07-10T09:00:46Z

Calls to db_export__thread() already have main_thread so there is no
reason to get it again, instead pass it as a parameter. Note that one
difference in this approach is that the main thread is not created if it
does not exist. It is better if it is not created because:
- If main_thread is being traced it will have been created already.
- If it is not being traced, there will be no other information about
it, and it will never get deleted because there will be no EXIT event.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/util/db-export.c | 29 ++++++++---------------------
tools/perf/util/db-export.h | 3 ++-
2 files changed, 10 insertions(+), 22 deletions(-)

diff --git a/tools/perf/util/db-export.c b/tools/perf/util/db-export.c
index bb696559cd9a..7ad596bef4a9 100644
--- a/tools/perf/util/db-export.c
+++ b/tools/perf/util/db-export.c
@@ -58,9 +58,9 @@ int db_export__machine(struct db_export *dbe, struct machine *machine)
}

int db_export__thread(struct db_export *dbe, struct thread *thread,
- struct machine *machine, struct comm *comm)
+ struct machine *machine, struct comm *comm,
+ struct thread *main_thread)
{
- struct thread *main_thread;
u64 main_thread_db_id = 0;
int err;

@@ -69,28 +69,19 @@ int db_export__thread(struct db_export *dbe, struct thread *thread,

thread->db_id = ++dbe->thread_last_db_id;

- if (thread->pid_ != -1) {
- if (thread->pid_ == thread->tid) {
- main_thread = thread;
- } else {
- main_thread = machine__findnew_thread(machine,
- thread->pid_,
- thread->pid_);
- if (!main_thread)
- return -ENOMEM;
+ if (main_thread) {
+ if (main_thread != thread) {
err = db_export__thread(dbe, main_thread, machine,
- comm);
+ comm, main_thread);
if (err)
- goto out_put;
+ return err;
if (comm) {
err = db_export__comm_thread(dbe, comm, thread);
if (err)
- goto out_put;
+ return err;
}
}
main_thread_db_id = main_thread->db_id;
- if (main_thread != thread)
- thread__put(main_thread);
}

if (dbe->export_thread)
@@ -98,10 +89,6 @@ int db_export__thread(struct db_export *dbe, struct thread *thread,
machine);

return 0;
-
-out_put:
- thread__put(main_thread);
- return err;
}

/*
@@ -323,7 +310,7 @@ int db_export__sample(struct db_export *dbe, union perf_event *event,
if (main_thread)
comm = machine__thread_exec_comm(al->machine, main_thread);

- err = db_export__thread(dbe, thread, al->machine, comm);
+ err = db_export__thread(dbe, thread, al->machine, comm, main_thread);
if (err)
goto out_put;

diff --git a/tools/perf/util/db-export.h b/tools/perf/util/db-export.h
index 148a657b1887..6e267321594c 100644
--- a/tools/perf/util/db-export.h
+++ b/tools/perf/util/db-export.h
@@ -75,7 +75,8 @@ void db_export__exit(struct db_export *dbe);
int db_export__evsel(struct db_export *dbe, struct perf_evsel *evsel);
int db_export__machine(struct db_export *dbe, struct machine *machine);
int db_export__thread(struct db_export *dbe, struct thread *thread,
- struct machine *machine, struct comm *comm);
+ struct machine *machine, struct comm *comm,
+ struct thread *main_thread);
int db_export__exec_comm(struct db_export *dbe, struct comm *comm,
struct thread *main_thread);
int db_export__comm_thread(struct db_export *dbe, struct comm *comm,
--
2.17.1