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charset=us-ascii Content-Disposition: inline In-Reply-To: <20240804005138.3722656-30-john.ogness@linutronix.de> Hi Linus, On Sun 2024-08-04 02:57:32, John Ogness wrote: > If legacy and nbcon consoles are registered and the nbcon > consoles are allowed to flush (i.e. no boot consoles > registered), the legacy consoles will no longer perform > direct printing on the panic CPU until after the backtrace > has been stored. This will give the safe nbcon consoles a > chance to print the panic messages before allowing the > unsafe legacy consoles to print. > > If no nbcon consoles are registered or they are not allowed > to flush, there is no change in behavior (i.e. legacy > consoles will always attempt to print from the printk() > caller context). I want to be sure that this is acceptable to you. This behavior has already been in the rejected pull request for 6.11, see https://lore.kernel.org/r/Zp-_7R49fIHgIhaq@pathway.suse.cz You did not complain about this particular change. But it is yet another buffering in critical situation which you do not like in general. It is a bit different from the buffering during Oops. In this case, the new nbcon consoles will still be flushed immediately. And the legacy consoles will be blocked only when there is a nbcon console. The buffering here should increase the chance to see the messages on the more safe (nbcon) consoles. The legacy consoles are less safe primary because of the bust_spinlocks(1) called earlier. I personally do not have strong opinion. The change makes sense. It looks like it should make more good than harm. But it is not a clear win. Best Regards, Petr