This is a note to let you know that I've just added the patch titled tracing: Treat recording comm for idle task as a success to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tracing-treat-recording-comm-for-idle-task-as-a-success.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From eaf260ac04d9b4cf9f458d5c97555bfff2da526e Mon Sep 17 00:00:00 2001 From: Joel Fernandes <joelaf@xxxxxxxxxx> Date: Thu, 6 Jul 2017 16:00:21 -0700 Subject: tracing: Treat recording comm for idle task as a success 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 @@ -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; /* Patches currently in stable-queue which might be from joelaf@xxxxxxxxxx are queue-4.9/tracing-treat-recording-comm-for-idle-task-as-a-success.patch