Messages in this thread | | | Date | Thu, 23 Aug 2012 11:50:22 +0200 | From | Michal Hocko <> | Subject | Re: Fixup the page of buddy_higher address's calculation |
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On Thu 23-08-12 16:40:13, Li Haifeng wrote: > From d7cd78f9d71a5c9ddeed02724558096f0bb4508a Mon Sep 17 00:00:00 2001 > From: Haifeng Li <omycle@gmail.com> > Date: Thu, 23 Aug 2012 16:27:19 +0800 > Subject: [PATCH] Fixup the page of buddy_higher address's calculation
Some general questions: Any word about the change? Is it really that obvious? Why do you think the current state is incorrect? How did you find out?
And more specific below:
> Signed-off-by: Haifeng Li <omycle@gmail.com> > --- > mm/page_alloc.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index ddbc17d..5588f68 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -579,7 +579,7 @@ static inline void __free_one_page(struct page *page, > combined_idx = buddy_idx & page_idx; > higher_page = page + (combined_idx - page_idx); > buddy_idx = __find_buddy_index(combined_idx, order + 1); > - higher_buddy = page + (buddy_idx - combined_idx); > + higher_buddy = page + (buddy_idx - page_idx);
We are finding buddy index for combined_idx so why should we use page_idx here?
> if (page_is_buddy(higher_page, higher_buddy, order + 1)) { > list_add_tail(&page->lru, > &zone->free_area[order].free_list[migratetype]); > -- > 1.7.5.4
-- Michal Hocko SUSE Labs
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