perf db-export: Pass main_thread to db_export__thread()

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>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190710085810.1650-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/db-export.c b/tools/perf/util/db-export.c
index 8fab57f..1450123 100644 (file)
--- a/tools/perf/util/db-export.c
+++ b/tools/perf/util/db-export.c
@@ -59,9 +59,9 @@ 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;
 
@@ -70,28 +70,19 @@ 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)
@@ -99,10 +90,6 @@ int db_export__thread(struct db_export *dbe, struct thread *thread,
                                          machine);
 
        return 0;
-
-out_put:
-       thread__put(main_thread);
-       return err;
 }
 
 /*
@@ -324,7 +311,7 @@ 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 148a657..6e26732 100644 (file)
--- 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,