Re: [PATCH] locking/lockdep: Add CONFIG_LOCKDEP_AGGRESSIVE

[Byungchul Park <byungchul.park@lge.com>]

On 12/13/2017 2:00 AM, Linus Torvalds wrote:
> On Mon, Dec 11, 2017 at 9:20 PM, Byungchul Park <byungchul.park@lge.com> wrote:
>>
>> The *problem* is false positives, since locks and waiters in
>> kernel are not classified properly
> 
> So the problem is that those false positives apparently end up being a
> big deal for the filesystem people.
> 
> I personally don't think the code itself has to be removed, but I do
> think that it should never have been added on as part of the generic
> lock proving, and should always have been a separate config option.

I admit it.

> I also feel that you dismiss "false positives" much too easily. A

I don't dismiss the ones easily...

Anyway, I mostly agree with your whole opinion.

Thanks for replying.

> false positive is a big problem - because it makes people ignore the
> real cases (or just disable the functionality entirely).
> 
> It's why I am very quick to disable compiler warnings that have false
> positives, for example. Just a couple of "harmless" false positive
> warnings will poison the real warnings for people because they'll get
> used to seeing warnings while building, and no longer actually look at
> them.
> 
>                   Linus
> 

-- 
Thanks,
Byungchul