Re: [PATCH printk v2 00/12] implement threaded console printing

John Ogness
2022-04-06T02:32:55Z

On 2022-04-05, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> From the list of patches and the only one I am Cc'ed to I can't find
> the answer to my question,

It seems lore is having trouble picking up the series. Until then, I've
pushed the series to github.com so you can see the code.

> i.e. does it take care about console_unregister() cases at run time?
> (We have some drivers to call ->exit() for console in that case,
> perhaps it should do something before calling it.)

Yes. In console_unregister(), the printing thread is shutdown before the
actual console unregistration takes place. The thread is shutdown here:

https://github.com/Linutronix/linux/blob/b27eb6c3d168d608b3a9d04578e030a3d79d889a/kernel/printk/printk.c#L3393

The console's exit() callback is below that:

https://github.com/Linutronix/linux/blob/b27eb6c3d168d608b3a9d04578e030a3d79d889a/kernel/printk/printk.c#L3429

> Would be nice to see some pointers where I can find the answer and
> maybe even describing in the cover-letter/commit
> message/documentation.

I suppose for the console thread patch [0] I could add a paragraph to
the commit message mentioning kernel thread shutdown for console
unregistration.

[0] https://github.com/Linutronix/linux/commit/e26ae677da2e339dd268c1f871b81e61e782393f

John