[PATCH 4.9 076/240] tracing: Treat recording comm for idle task as a success

Greg Kroah-Hartman
2021-05-20T11:13:52Z

From: Joel Fernandes <joelaf@google.com>

commit eaf260ac04d9b4cf9f458d5c97555bfff2da526e upstream.

Currently we stop recording comm for non-idle tasks when switching from/to idle
task since we treat that as a record failure. Fix that by treat recording of
comm for idle task as a success.

Link: http://lkml.kernel.org/r/20170706230023.17942-1-joelaf@google.com

Cc: kernel-team@android.com
Cc: Ingo Molnar <mingo@redhat.com>
Reported-by: Michael Sartain <mikesart@gmail.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/trace.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1811,7 +1811,11 @@ static int trace_save_cmdline(struct tas
{
unsigned pid, idx;

- if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
+ /* treat recording of idle task as a success */
+ if (!tsk->pid)
+ return 1;
+
+ if (unlikely(tsk->pid > PID_MAX_DEFAULT))
return 0;

/*