On Thu, Feb 20, 2020 at 02:11:45PM +0900, js1304@xxxxxxxxx wrote: > From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> > > Current implementation of LRU management for anonymous page has some > problems. Most important one is that it doesn't protect the workingset, > that is, pages on the active LRU list. Although, this problem will be > fixed in the following patchset, the preparation is required and > this patch does it. > > What following patchset does is to restore workingset protection. In this > case, newly created or swap-in pages are started their lifetime on the > inactive list. If inactive list is too small, there is not enough chance > to be referenced and the page cannot become the workingset. > > In order to provide enough chance to the newly anonymous pages, this patch > makes active/inactive LRU ratio as 1:1. Patch 8/9 is a revert of this patch. I assume you did this for the series to be bisectable and partially revertable, but I'm not sure keeping only the first and second patch would be safe: they reduce workingset protection quite dramatically on their own (on a 10G system from 90% of RAM to 50% e.g.) and likely cause regressions. So while patch 2 is probably a lot better with patch 1 than without, it seems a bit unnecessary since we cannot keep patch 2 on its own. We need the rest of the series to make these changes. On the other hand, the patch is small and obviously correct. So no strong feelings either way. > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Reviewed-by: Johannes Weiner <hannes@xxxxxxxxxxx>
