Hi John, On Fri, Jul 27, 2012 at 8:57 PM, John Stultz <john.stultz@xxxxxxxxxx> wrote: > So after not getting too much positive feedback on my last > attempt at trying to use a non-shrinker method for managing > & purging volatile ranges, I decided I'd go ahead and try > to implement something along Minchan's ERECLAIM LRU list > idea. Agree that there hasn't been much feedback from MM folks yet - sorry about that :/ I think one issue might be that most people don't have a good background on how the feature is intended to be used, and it is very difficult to comment meaningfully without that. As for myself, I have been wondering: - Why the feature needs to be on a per-range basis, rather than per-file. Is this simply to make it easier to transition the android use case from whatever they are doing right now, or is it that the object boundaries within a file can't be known in advance, and thus one wouldn't know how to split objects accross different files ? Or could it be that some of the objects would be small (less than a page) so space use would be inefficient if they were placed in different files ? Or just that there would be too many files for efficient management ? - What are the desired semantics for the volatile objects. Can the objects be accessed while they are marked as volatile, or do they have to get unmarked first ? Is it really the case that we always want to reclaim from volatile objects first, before any other kind of caches we might have ? This sounds like a very strong hint, and I think I would be more comfortable with something more subtle if that's possible. Also, if we have several volatile objects to reclaim from, is it desirable to reclaim from the one that's been marked volatile the longest or does it make no difference ? When an object is marked volatile, would it be sufficient to ensure it gets placed on the inactive list (maybe with the referenced bit cleared) and let the normal reclaim algorithm get to it, or is that an insufficiently strong hint somehow ? Basically, having some background information of how android would be using the feature would help us better understand the design decision here, I think. -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>