Re: [RFC][PATCHv2 2/4] printk: move printk_safe macros to printk header

Petr Mladek
2018-10-22T14:30:35Z

On Wed 2018-10-17 16:00:44, Peter Zijlstra wrote:
> On Wed, Oct 17, 2018 at 12:50:15PM +0200, Petr Mladek wrote:
> > Also note that by deferred printk I mean deferring the console
> > handling! IMHO, there are _no more problems_ with storing
> > the messages into the buffer if we accept that the current
> > very limited use of printk_safe per-cpu buffers is easier
> > than any complicated generic lockless buffer.
>
> They hide messages. The whole two radically different printk paths is
> also quite horrible.

I agree that having everything in one buffer with unified
and safe access from any context would be a great win.

> And lockless buffers aren't all _that_ complicated, esp. not when
> performance isn't the top priority.
>
> And earlycon is mostly usable, esp. the serial ones. Those, when
> configured, should synchronously print along. The current design
> also makes that difficult.
>
> A wee little like so; typed in a hurry, never been near a compiler.

Thanks a lot for the code. I still need to find time to better
understand it. Anyway, it looks worth considering.

Best Regards,
Petr