On Sat, May 20, 2023 at 5:58 AM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, 19 May 2023 16:41:41 +0800 Zhaoyang Huang <huangzhaoyang@xxxxxxxxx> wrote:
>
> > any comments?
>
> Have any of the regular CMA developers commented on a version of this?
None comments until now. IMO, it is mainly affect reclaiming process.
>
>
> I have a couple of little complaints:
>
> > diff --git a/mm/vmscan.c b/mm/vmscan.c
> > index bd6637f..19fb445 100644
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -2225,10 +2225,16 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
> > unsigned long nr_skipped[MAX_NR_ZONES] = { 0, };
> > unsigned long skipped = 0;
> > unsigned long scan, total_scan, nr_pages;
> > + bool cma_cap = true;
> > + struct page *page;
> > LIST_HEAD(folios_skipped);
> >
> > total_scan = 0;
> > scan = 0;
> > + if ((IS_ENABLED(CONFIG_CMA)) && !current_is_kswapd()
> > + && (gfp_migratetype(sc->gfp_mask) != MIGRATE_MOVABLE))
> > + cma_cap = false;
> > +
>
> A code comment above this alteration would be good. Tell the reader
> why we're doing this.
ok, will update
>
>
> > while (scan < nr_to_scan && !list_empty(src)) {
> > struct list_head *move_to = src;
> > struct folio *folio;
> > @@ -2239,12 +2245,17 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
> > nr_pages = folio_nr_pages(folio);
> > total_scan += nr_pages;
> >
> > - if (folio_zonenum(folio) > sc->reclaim_idx) {
> > + page = &folio->page;
> > +
> > + if ((folio_zonenum(folio) > sc->reclaim_idx)
> > +#ifdef CONFIG_CMA
> > + || (get_pageblock_migratetype(page) == MIGRATE_CMA && !cma_cap)
> > +#endif
> > + ) {
> > nr_skipped[folio_zonenum(folio)] += nr_pages;
> > move_to = &folios_skipped;
> > goto move;
> > }
>
> That's pretty ugly. Can we use IS_ENABLED(CONFIG_CMA) here to avoid
> the ifdef?
ok
>
