On 2019/10/29 17:40, Michal Hocko wrote: > 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. As you has said, Minchan fix the same kind of bug by checking PageUnevictable (I did not notice before) Wait for Minchan to see whether he has better reason. thanks, Sincerely, zhong jiang
