On Wed, Dec 20, 2023 at 10:14 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > On Wed, Dec 20, 2023 at 06:29:48PM +0800, zhaoyang.huang wrote: > > From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx> > > > > Inactive mapped folio will be promoted to active only when it is > > scanned in shrink_inactive_list, while the vfs folio will do this > > immidiatly when it is accessed. These will introduce two affections: > > > > 1. NR_ACTIVE_FILE is not accurate as expected. > > 2. Low reclaiming efficiency caused by dummy nactive folio which should > > be kept as earlier as shrink_active_list. > > > > I would like to suggest mark the folio be accessed in minor fault to > > solve this situation. > > This isn't going to be as effective as you imagine. Almost all file > faults are handled through filemap_map_pages(). So I must ask, what > testing have you done with this patch? > > And while you're gathering data, what effect would this patch have on your > workloads? Thanks for heads-up, I am out of date for readahead mechanism. My goal is to have mapped file pages behave like other pages which could be promoted immediately when they are accessed. I will update the patch and provide benchmark data in new patch set. > > diff --git a/mm/filemap.c b/mm/filemap.c > index 2e6b1daac6cd..8cecf82dcc5a 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -3418,6 +3418,7 @@ static struct folio *next_uptodate_folio(struct xa_state *xas, > max_idx = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE); > if (xas->xa_index >= max_idx) > goto unlock; > + folio_mark_accessed(folio); > return folio; > unlock: > folio_unlock(folio); >
