From: Joel Fernandes <joelaf@xxxxxxxxxx> 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@xxxxxxxxxx Cc: kernel-team@xxxxxxxxxxx Cc: Ingo Molnar <mingo@xxxxxxxxxx> Reported-by: Michael Sartain <mikesart@xxxxxxxxx> Signed-off-by: Joel Fernandes <joelaf@xxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/trace.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1564,7 +1564,11 @@ 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; /*
