Messages in this thread | | | Subject | Re: [RFC PATCH] mm/page_alloc: fix counting of free pages after take off from buddy | From | David Hildenbrand <> | Date | Wed, 28 Apr 2021 16:54:59 +0200 |
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On 21.04.21 04:04, Ding Hui wrote: > Recently we found there is a lot MemFree left in /proc/meminfo after > do a lot of pages soft offline. > > I think it's incorrect since NR_FREE_PAGES should not contain HWPoison pages. > After take_page_off_buddy, the page is no longer belong to buddy > allocator, and will not be used any more, but we maybe missed accounting > NR_FREE_PAGES in this situation. > > Signed-off-by: Ding Hui <dinghui@sangfor.com.cn> > --- > mm/page_alloc.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index cfc72873961d..8d65b62784d8 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -8947,6 +8947,7 @@ bool take_page_off_buddy(struct page *page) > del_page_from_free_list(page_head, zone, page_order); > break_down_buddy_pages(zone, page_head, page, 0, > page_order, migratetype); > + __mod_zone_page_state(zone, NR_FREE_PAGES, -1); > ret = true; > break; > } >
Should this use __mod_zone_freepage_state() instead?
-- Thanks,
David / dhildenb
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