On Thu, Jul 19, 2018 at 10:37:23PM +0900, Tetsuo Handa wrote: > This patch can be applied before proposing abovementioned changes. > Since there are many kernel threads whose backtrace is boring due to idly > waiting for an event inside the main loop, this patch introduces a kernel > config option (which allows SysRq-t to use one-liner backtrace for threads > idly waiting for an event) and simple helpers (which allow current thread > to declare that current thread is about to start/end idly waiting).
> diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c > index f776807..6b8c8bd 100644 > --- a/drivers/base/devtmpfs.c > +++ b/drivers/base/devtmpfs.c > @@ -406,7 +406,9 @@ static int devtmpfsd(void *p) > } > __set_current_state(TASK_INTERRUPTIBLE); > spin_unlock(&req_lock); > + start_idle_sleeping(); > schedule(); > + end_idle_sleeping(); > } > return 0; > out: So I _really_ hate the idea of sprinking that all around the kernel like this.