On Mon, Feb 10, 2020 at 05:10:21PM -0800, Matthew Wilcox wrote: > On Mon, Feb 10, 2020 at 04:19:58PM -0800, Minchan Kim wrote: > > filemap_fault > > find a page form page(PG_uptodate|PG_readahead|PG_writeback) > > Uh ... That shouldn't be possible. Please see shrink_page_list. Vmscan uses PG_reclaim to accelerate page reclaim when the writeback is done so the page will have both flags at the same time and the PG reclaim could be regarded as PG_readahead in fault conext. > > /* > * Same bit is used for PG_readahead and PG_reclaim. > */ > if (PageWriteback(page)) > return; > > ClearPageReadahead(page); >
