Re: [PATCH] siox: don't create a thread without starting it

From: Schenk, Gavin
Date: Fri Jun 29 2018 - 02:27:35 EST


On Thu, 2018-06-28 at 09:57 +0200, Uwe Kleine-KÃnig wrote:
> When a siox master device is registered a kthread is created that is
> only started when triggered by userspace. So this thread might be in
> TASK_UNINTERRUPTIBLE state for long and trigger a warning
>
> [ 241.130465] INFO: task siox-0:626 blocked for more than 120 seconds.
>
> with the respective debug settings enabled. It might be right to put an
> unstarted thread to TASK_IDLE (in kernel/kthread.c:kthread()) instead,
> but independant of this discussion it is cleaner for
> siox_master_register() to start the thread immediately. The effect is
> that it enters its own waiting state and then stays in state TASK_IDLE
> which doesn't trigger the above warning.
>
> As siox_poll_thread() uses some variables of the device the
> initialisation of these is moved before thread creation.
>
> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>
> ---
Acked-by: Gavin Schenk <g.schenk@xxxxxxxxxxxx

I tested that this warning is gone with this patch.

Regards
Gavin Schenk