Re: [PATCH] mm: warn only once if page table misaccounting is detected

From: Heiko Carstens
Date: Tue Nov 27 2018 - 09:36:49 EST


On Tue, Nov 27, 2018 at 02:19:16PM +0100, Michal Hocko wrote:
> On Tue 27-11-18 09:36:03, Heiko Carstens wrote:
> > Use pr_alert_once() instead of pr_alert() if page table misaccounting
> > has been detected.
> >
> > If this happens once it is very likely that there will be numerous
> > other occurrence as well, which would flood dmesg and the console with
> > hardly any added information. Therefore print the warning only once.
>
> Have you actually experience a flood of these messages? Is one per mm
> message really that much?

Yes, I did. Since in this case all compat processes caused the message
to appear, I saw thousands of these messages.

> If yes why rss counters do not exhibit the same problem?

No rss counter messages appeared. Or do you suggest that the other
pr_alert() within check_mm() should also be changed?