Re: WARNING in try_charge

On Mon, Aug 06, 2018 at 04:21:24PM +0200, Michal Hocko wrote:

On Mon 06-08-18 13:57:38, Dmitry Vyukov wrote:

quoted

On Mon, Aug 6, 2018 at 1:02 PM, Michal Hocko [off-list ref] wrote:

quoted

If you have a strong reason to believe that this is an abuse of WARN I
am all happy to change that. But I haven't heard any yet, to be honest.

WARN must not be used for anything that is not kernel bugs. If this is
not kernel bug, WARN must not be used here.

This is rather strong wording without any backing arguments. I strongly
doubt 90% of existing WARN* match this expectation. WARN* has
traditionally been a way to tell that something suspicious is going on.
Those situation are mostly likely not fatal but it is good to know they
are happening.

I have to agree with Dmitry here. WARN should indicate a real kernel
issue, not user input that knowingly triggers undesirable behavior in
the kernel. It's our assert() for states we don't think are possible.

I would wager that MOST developers and users understand it that way.