On Sun, Mar 13, 2022 at 2:27 PM Eric Dumazet <[email protected]> wrote:
>
> On Sun, Mar 13, 2022 at 2:18 PM Matthew Wilcox <[email protected]> wrote:
> >
> > On Sun, Mar 13, 2022 at 02:10:12PM -0700, Eric Dumazet wrote:
> > > @@ -3065,6 +3062,12 @@ static int rmqueue_bulk(struct zone *zone,
> > > unsigned int order,
> > > */
> > > __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
> > > spin_unlock(&zone->lock);
> > > + list_for_each_entry_safe(page, tmp, list, lru) {
> > > + if (unlikely(check_pcp_refill(page))) {
> > > + list_del(&page->lru);
> > > + allocated--;
> > > + }
> > > + }
> >
> > ... you'd need to adjust __mod_zone_page_state() too, right?
>
> Probably !
> This was only to show the basic idea, as I said, not even compiled or tested :)
I can test the following:
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1804287c1b792b8aa0e964b17eb002b6b1115258..30a1abf40ea7e9104bfd24a42d9e0c8ebb152fc4
100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3024,7 +3024,9 @@ static int rmqueue_bulk(struct zone *zone,
unsigned int order,
unsigned long count, struct list_head *list,
int migratetype, unsigned int alloc_flags)
{
+ struct page *page, *tmp;
int i, allocated = 0;
+ int free_cma_pages = 0;
/*
* local_lock_irq held so equivalent to spin_lock_irqsave for
@@ -3032,14 +3034,10 @@ static int rmqueue_bulk(struct zone *zone,
unsigned int order,
*/
spin_lock(&zone->lock);
for (i = 0; i < count; ++i) {
- struct page *page = __rmqueue(zone, order, migratetype,
- alloc_flags);
+ page = __rmqueue(zone, order, migratetype, alloc_flags);
if (unlikely(page == NULL))
break;
- if (unlikely(check_pcp_refill(page)))
- continue;
-
/*
* Split buddy pages returned by expand() are received here in
* physical page order. The page is added to the tail of
@@ -3052,9 +3050,6 @@ static int rmqueue_bulk(struct zone *zone,
unsigned int order,
*/
list_add_tail(&page->lru, list);
allocated++;
- if (is_migrate_cma(get_pcppage_migratetype(page)))
- __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
- -(1 << order));
}
/*
@@ -3065,6 +3060,16 @@ static int rmqueue_bulk(struct zone *zone,
unsigned int order,
*/
__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
spin_unlock(&zone->lock);
+ list_for_each_entry_safe(page, tmp, list, lru) {
+ if (unlikely(check_pcp_refill(page))) {
+ list_del(&page->lru);
+ allocated--;
+ } else if (is_migrate_cma(get_pcppage_migratetype(page))) {
+ free_cma_pages++;
+ }
+ }
+ if (free_cma_pages)
+ __mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
-(free_cma_pages << order));
return allocated;
}