On Tue 27-11-18 15:36:38, Heiko Carstens wrote: > 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.
This means something went colossally wrong and seeing an avalanche of messages might be actually helpful because you can at least see the pattern. I wonder whether the underlying issue would be obvious from a single instance. Maybe we want ratelimit instead? > > 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? Whatever we go with (and I do not have a strong opinion here) we should be consistent I believe. -- Michal Hocko SUSE Labs