Re: [PATCH printk v6 00/30] wire up write_atomic() printing

From: Petr Mladek
Date: Tue May 28 2024 - 09:36:10 EST


On Tue 2024-05-28 12:10:22, Petr Mladek wrote:
> On Mon 2024-05-27 08:43:19, John Ogness wrote:
> > Hi,
> >
> > This is v6 of a series to wire up the nbcon consoles so that
> > they actually perform printing using their write_atomic()
> > callback. v5 is here [0]. For information about the motivation
> > of the atomic consoles, please read the cover letter of v1 [1].
> >
> > The main focus of this series:
> >
> > - For nbcon consoles, always call write_atomic() directly from
> > printk() caller context for the panic CPU.
> >
> > - For nbcon consoles, call write_atomic() when unlocking the
> > console lock.
> >
> > - Only perform the console lock/unlock dance if legacy or boot
> > consoles are registered.
> >
> > - For legacy consoles, if nbcon consoles are registered, do not
> > attempt to print from printk() caller context for the panic
> > CPU until nbcon consoles have had a chance to print the most
> > significant messages.
> >
> > - Mark emergency sections. In these sections printk() calls
> > will only store the messages. Upon exiting the emergency
> > section, nbcon consoles are flushed directly. If legacy
> > consoles cannot be flushed safely, an irq_work is triggered
> > to do the legacy console flushing.
> >
> > This series does _not_ include threaded printing or nbcon
> > drivers. Those features will be added in separate follow-up
> > series.
> >
> > Note: With this series, a system with _only_ nbcon consoles
> > registered will not perform console printing unless the
> > console lock or nbcon port lock are used or on panic.
> > This is on purpose. When nbcon kthreads are introduced,
> > they will fill the gaps.
>
> The series seems to be ready for linux-next from my POV.
>
> I am going to push it there so that we get as much testing
> as possible before the next merge window.

JFYI, the patchset has been committed into printk/linux.git,
branch rework/write-atomic.

Best Regards,
Petr