On Tue 24-11-15 16:07:40, Vladimir Davydov wrote: > On Tue, Nov 24, 2015 at 12:55:00PM +0100, Michal Hocko wrote: > > zone_reclaimable_pages considers all anonymous pages on LRUs reclaimable > > if there is at least one entry on the swap storage left. This can be > > really misleading when the swap is short on space and skew reclaim > > decisions based on zone_reclaimable_pages. Fix this by clamping the > > number to the minimum of the available swap space and anon LRU pages. > > Suppose there's 100M of swap and 1G of anon pages. This patch makes > zone_reclaimable_pages return 100M instead of 1G in this case. If you > rotate 600M of oldest anon pages, which is quite possible, > zone_reclaimable will start returning false, which is wrong, because > there are still 400M pages that were not even scanned, besides those > 600M of rotated pages could have become reclaimable after their ref bits > got cleared.
Uhm, OK, I guess you are right. Making zone_reclaimable less conservative can lead to hard to expect results. Scratch this patch please. > I think it is the name of zone_reclaimable_pages which is misleading. It > should be called something like "zone_scannable_pages" judging by how it > is used in zone_reclaimable. Thanks! -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
