Re: [RFC 2/7] mm: change PAGEREF_RECLAIM_CLEAN with PAGE_REFRECLAIM

[Minchan Kim <minchan@kernel.org>]

On Mon, May 20, 2019 at 12:50:13PM -0400, Johannes Weiner wrote:
> On Mon, May 20, 2019 at 12:52:49PM +0900, Minchan Kim wrote:
> > The local variable references in shrink_page_list is PAGEREF_RECLAIM_CLEAN
> > as default. It is for preventing to reclaim dirty pages when CMA try to
> > migrate pages. Strictly speaking, we don't need it because CMA didn't allow
> > to write out by .may_writepage = 0 in reclaim_clean_pages_from_list.
> >
> > Moreover, it has a problem to prevent anonymous pages's swap out even
> > though force_reclaim = true in shrink_page_list on upcoming patch.
> > So this patch makes references's default value to PAGEREF_RECLAIM and
> > rename force_reclaim with skip_reference_check to make it more clear.
> > 
> > This is a preparatory work for next patch.
> > 
> > Signed-off-by: Minchan Kim <minchan@kernel.org>
> 
> Looks good to me, just one nit below.
> 
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>

Thanks, Johannes.

> 
> > ---
> >  mm/vmscan.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/mm/vmscan.c b/mm/vmscan.c
> > index d9c3e873eca6..a28e5d17b495 100644
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -1102,7 +1102,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
> >  				      struct scan_control *sc,
> >  				      enum ttu_flags ttu_flags,
> >  				      struct reclaim_stat *stat,
> > -				      bool force_reclaim)
> > +				      bool skip_reference_check)
> 
> "ignore_references" would be better IMO

Sure.