Re: [PATCH] timers: fix synchronization rules in comments of del_timer_sync

[Thomas Gleixner]

On Fri, Jul 01 2022 at 16:55, Duoming Zhou wrote:
> - * Synchronization rules: Callers must prevent restarting of the timer,
> - * otherwise this function is meaningless. It must not be called from
> - * interrupt contexts unless the timer is an irqsafe one. The caller must
> - * not hold locks which would prevent completion of the timer's
> - * handler. The timer's handler must not call add_timer_on(). Upon exit the
> - * timer is not queued and the handler is not running on any CPU.
> + * Synchronization rules: Callers must prevent restarting of the timer in
> + * other places except for the timer's handler, otherwise this function is
> + * meaningless. It must not be called from interrupt contexts unless the
> + * timer is an irqsafe one. The caller must not hold locks which would
> + * prevent completion of the timer's handler. The timer's handler must
> + * not call add_timer_on().

If we are making this correct: What's so special about add_timer_on()?

Thanks,

        tglx