Re: [PATCH printk v3 11/19] printk: nbcon: Rely on kthreads for normal operation
From: Petr Mladek
Date: Thu Aug 01 2024 - 05:37:03 EST
On Wed 2024-07-31 17:31:02, John Ogness wrote:
> On 2024-07-31, Petr Mladek <pmladek@xxxxxxxx> wrote:
> >> @@ -4102,8 +4139,10 @@ static bool __pr_flush(struct console *con, int timeout_ms, bool reset_on_progre
> >> * that they make forward progress, so only increment
> >> * @diff for usable consoles.
> >> */
> >> - if (!console_is_usable(c, flags, true))
> >> + if (!console_is_usable(c, flags, true) &&
> >> + !console_is_usable(c, flags, false)) {
> >
> > This looks weird. nbcon console can't make progress when
> > "write_atomic" is not implemented and the kthreads are not
> > running.
> >
> > I should be:
> >
> > if (!((console_is_usable(c, flags, true)) ||
> > (console_is_usable(c, flags, false) && printk_kthreads_running))) {
>
> I would prefer to have the printk_kthreads_running check within
> console_is_usable() for the !use_atomic case.
Makes sense.
> > That said. Do we really want to support nbcon consoles without
> > @write_atomic() callback?
>
> We must. Graphic consoles will not be able to implement
> write_atomic(). Network and USB consoles probably will not be able to
> implement it either.
I see.
Best Regards,
Petr