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@xxxxxxxxxxxxxx> --- 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
