On Mon, Feb 26, 2018 at 01:53:10PM -0800, David Rientjes wrote:
> On Mon, 26 Feb 2018, Aaron Lu wrote:
>
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index 3154859cccd6..35576da0a6c9 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -1116,13 +1116,11 @@ static void free_pcppages_bulk(struct zone *zone,
> > int count,
> > int migratetype = 0;
> > int batch_free = 0;
> > bool isolated_pageblocks;
> > + struct page *page, *tmp;
> > + LIST_HEAD(head);
> >
> > pcp->count -= count;
> > - spin_lock(&zone->lock);
> > - isolated_pageblocks = has_isolate_pageblock(zone);
> > -
> > while (count) {
> > - struct page *page;
> > struct list_head *list;
> >
> > /*
> > @@ -1144,26 +1142,31 @@ static void free_pcppages_bulk(struct zone *zone,
> > int count,
> > batch_free = count;
> >
> > do {
> > - int mt; /* migratetype of the to-be-freed page */
> > -
> > page = list_last_entry(list, struct page, lru);
> > /* must delete as __free_one_page list manipulates */
>
> Looks good in general, but I'm not sure how I reconcile this comment with
> the new implementation that later links page->lru again.
Thanks for pointing this out.
I think the comment is useless now since there is a list_add_tail right
below so it's obvious we need to take the page off its original list.
I'll remove the comment in an update.
>
> > list_del(&page->lru);
> >
> > - mt = get_pcppage_migratetype(page);
> > - /* MIGRATE_ISOLATE page should not go to pcplists */
> > - VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
> > - /* Pageblock could have been isolated meanwhile */
> > - if (unlikely(isolated_pageblocks))
> > - mt = get_pageblock_migratetype(page);
> > -
> > if (bulkfree_pcp_prepare(page))
> > continue;
> >
> > - __free_one_page(page, page_to_pfn(page), zone, 0, mt);
> > - trace_mm_page_pcpu_drain(page, 0, mt);
> > + list_add_tail(&page->lru, &head);
> > } while (--count && --batch_free && !list_empty(list));
> > }
