On 2023/11/21 21:00, Michal Hocko wrote: > On Tue 21-11-23 17:06:24, Liu Shixin wrote: > > However, in swapcache_only mode, the scan count still increased when scan > non-swapcache pages because there are large number of non-swapcache pages > and rare swapcache pages in swapcache_only mode, and if the non-swapcache > is skipped and do not count, the scan of pages in isolate_lru_folios() can > eventually lead to hung task, just as Sachin reported [2]. > I find this paragraph really confusing! I guess what you meant to say is > that a real swapcache_only is problematic because it can end up not > making any progress, correct? This paragraph is going to explain why checking swapcache_only after scan += nr_pages; > > AFAIU you have addressed that problem by making swapcache_only anon LRU > specific, right? That would be certainly more robust as you can still > reclaim from file LRUs. I cannot say I like that because swapcache_only > is a bit confusing and I do not think we want to grow more special > purpose reclaim types. Would it be possible/reasonable to instead put > swapcache pages on the file LRU instead? It looks like a good idea, but I'm not sure if it's possible. I can try it, is there anything to pay attention to? Thanks,
