On Tue 29-10-19 17:30:57, zhong jiang wrote: > On 2019/10/29 16:11, Michal Hocko wrote: > > [Cc Minchan] [...] > > Removing a long existing BUG_ON begs for a much better explanation. > > shrink_page_list is not a trivial piece of code but I _suspect_ that > > removing it should be ok for mapped pages at least (try_to_unmap) but I > > am not so sure how unmapped unevictable pages are handled from top of my > > head. > As to the unmapped unevictable pages. shrink_page_list has taken that into account. > > shinkr_page_list > page_evictable --> will filter the unevictable pages to putback its lru. Ohh, it is right there at the top. Missed it. The check has been added by Nick along with the BUG_ON. So it is sounds more like a "this shouldn't happen" bugon. I wouldn't mind to remove it with that justification. -- Michal Hocko SUSE Labs
