On Wed, Dec 09, 2020 at 12:01:27PM +0000, Pavel Begunkov wrote: > On 09/12/2020 08:40, Christoph Hellwig wrote: > >> + /* > >> + * In practice groups of pages tend to be accessed/reclaimed/refaulted > >> + * together. To not go over bvec for those who didn't set BIO_WORKINGSET > >> + * approximate it by looking at the first page and inducing it to the > >> + * whole bio > >> + */ > >> + if (unlikely(PageWorkingset(iter->bvec->bv_page))) > >> + bio_set_flag(bio, BIO_WORKINGSET); > > > > IIRC the feedback was that we do not need to deal with BIO_WORKINGSET > > at all for direct I/O. > > I was waiting for the conversation to unfold, i.e. for Johannes to > answer. BTW, would the same (skipping BIO_WORKINGSET) stand true for > iomap? iomap direct I/O: yes.