On Fri 18-09-20 04:27:13, Yu Zhao wrote:
> On Fri, Sep 18, 2020 at 09:37:00AM +0200, Michal Hocko wrote:
[...]
> And I have asked this before: why does 'the compound page situation'
> even matter here? Perhaps if you could give a concrete example related
> to the code change and help me understand your concern?
Forgot to answer this part. The compound page concern is a misreading of
the patch on my end. I have missed you are using page_off_lru in this
(move_pages_to_lru) path and that you rely on release_pages to do the
clean up on you. I still find it rather awkward that page_off_lru has
such side effects but I am not deeply familiar with the reasoning
behind so I will rather shut up now.
[...]
> > > @@ -1860,14 +1859,11 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
> > > lruvec = mem_cgroup_page_lruvec(page, pgdat);
> > >
> > > SetPageLRU(page);
> > > - lru = page_lru(page);
> > > -
> > > add_page_to_lru_list(page, lruvec, lru);
> > >
> > > if (put_page_testzero(page)) {
> > > __ClearPageLRU(page);
> > > - __ClearPageActive(page);
> > > - del_page_from_lru_list(page, lruvec, lru);
> > > + del_page_from_lru_list(page, lruvec, page_off_lru(page));
> > >
> > > if (unlikely(PageCompound(page))) {
> > > spin_unlock_irq(&pgdat->lru_lock);
> > > --
> > > 2.28.0.681.g6f77f65b4e-goog
> >
> > --
> > Michal Hocko
> > SUSE Labs
--
Michal Hocko
SUSE Labs
