On (08/03/18 14:23), Sergey Senozhatsky wrote: > > Hmm, any chance a WB device can be async on its own? We add a page > to a new bio and submit it to another async device driver. Then we > return back to the upper layer (swap), which can free a page before > the device picks up a request. Can this happen? Nevermind these questions. Sorry for the noise. -ss