Re: [PATCH printk 10/18] kgbd: Pretend that console list walk is safe

[Petr Mladek]

On Fri 2022-09-30 15:50:56, John Ogness wrote:
> On 2022-09-30, Petr Mladek <pmladek@xxxxxxxx> wrote:
> > Anyway, what about using the later added SRCU walk here?
> > After all, this is exactly what RCU is for, isn't it?
> 
> So I think a lot of the problems with this series is that SRCU is
> introduced too late. We are debating things in patch 6 that are
> irrelevant by patch 12.

> I will rework the series so that the changes come in the following
> order:
> 
> 1. provide an atomic console_is_enabled()
>
> 2. convert the list to SRCU
> 
> 3. move all iterators from console_lock()/console_trylock() to SRCU
> 
> Step 3 may result in console_lock()/console_trylock() calls disappearing
> or relocating to where they are needed for non-list-synchronization
> purposes.

I agree that introding SRCU as early as possible would
help. The current patchset converts the same code several times...

Best Regards,
Petr