Re: printk_ratelimited() && proc/sys/kernel/printk_ratelimit*

From: Linus Torvalds
Date: Wed Mar 20 2019 - 13:30:34 EST

On Wed, Mar 20, 2019 at 10:03 AM Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> At the same time, printk_ratelimited() uses a static ratelimit_state, so user-
> space can't override the default DEFAULT_RATELIMIT_.* numbers.
> Isn't it strange? Shouldn't printk_ratelimited() use printk_ratelimit_state ?

No it shouldn't.

Each printk_ratelimited() is independent, and that's very much on purpose.

One screaming printk shouldn't mean that every *other* printk would be shut up.

That said, it's likely true that nobody should really use
printk_ratelimited() anyway. But if two different users do, they
definitely shouldn't then affect each other.