On Fri, 1 Feb 2019, Vlastimil Babka wrote: > > Well, but rss update will not tell you that the page has been faulted in > > which is the most interesting part. > > Sure, but the patch doesn't add back that capability neither. It allows > to recognize page being reclaimed, and I argue you can infer that from > rss change as well. That change is mentioned in the last paragraph in > changelog, and I thought "add a hard to evaluate side channel" in your > reply referred to that. It doesn't add back the "original" side channel > to detect somebody else accessed a page. On Fri, 1 Feb 2019, Vlastimil Babka wrote: > > Is this really worth it? Do we know about any specific usecase that > > would benefit from this change? TBH I would rather wait for the report > > than add a hard to evaluate side channel. > > Well it's not that complicated IMHO. Linus said it's worth trying, so > let's see how he likes the result. The side channel exists anyway as > long as process can e.g. check if its rss shrinked, and I doubt we are > going to remove that possibility. Linus, do you have any opinion here? I have a hunch that mm maintainers are keeping this on a backburner because there might still open question(s) in the air. Thanks, -- Jiri Kosina SUSE Labs
