Messages in this thread Patch in this message | | | From | Andy Whitcroft <> | Subject | [PATCH 1/1] hugetlb: pull gigantic page initialisation out of the default path | Date | Wed, 8 Oct 2008 10:34:59 +0100 |
| |
As we can determine exactly when a gigantic page is in use we can optimise the common regular page cases by pulling out gigantic page initialisation into its own function. As gigantic pages are never released to buddy we do not need a destructor. This effectivly reverts the previous change to the main buddy allocator. It also adds a paranoid check to ensure we never release gigantic pages from hugetlbfs to the main buddy.
Signed-off-by: Andy Whitcroft <apw@shadowen.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> --- mm/hugetlb.c | 4 +++- mm/internal.h | 1 + mm/page_alloc.c | 26 +++++++++++++++++++------- 3 files changed, 23 insertions(+), 8 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index bb5cf81..716b151 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -460,6 +460,8 @@ static void update_and_free_page(struct hstate *h, struct page *page) { int i; + BUG_ON(h->order >= MAX_ORDER); + h->nr_huge_pages--; h->nr_huge_pages_node[page_to_nid(page)]--; for (i = 0; i < pages_per_huge_page(h); i++) { @@ -984,7 +986,7 @@ static void __init gather_bootmem_prealloc(void) struct hstate *h = m->hstate; __ClearPageReserved(page); WARN_ON(page_count(page) != 1); - prep_compound_page(page, h->order); + prep_compound_gigantic_page(page, h->order); prep_new_huge_page(h, page, page_to_nid(page)); } } diff --git a/mm/internal.h b/mm/internal.h index 08b8dea..92729ea 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -17,6 +17,7 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, unsigned long floor, unsigned long ceiling); extern void prep_compound_page(struct page *page, unsigned long order); +extern void prep_compound_gigantic_page(struct page *page, unsigned long order); static inline void set_page_count(struct page *page, int v) { diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 27b8681..dbeb3f8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -268,14 +268,28 @@ void prep_compound_page(struct page *page, unsigned long order) { int i; int nr_pages = 1 << order; + + set_compound_page_dtor(page, free_compound_page); + set_compound_order(page, order); + __SetPageHead(page); + for (i = 1; i < nr_pages; i++) { + struct page *p = page + i; + + __SetPageTail(p); + p->first_page = page; + } +} + +void prep_compound_gigantic_page(struct page *page, unsigned long order) +{ + int i; + int nr_pages = 1 << order; struct page *p = page + 1; set_compound_page_dtor(page, free_compound_page); set_compound_order(page, order); __SetPageHead(page); - for (i = 1; i < nr_pages; i++, p++) { - if (unlikely((i & (MAX_ORDER_NR_PAGES - 1)) == 0)) - p = pfn_to_page(page_to_pfn(page) + i); + for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { __SetPageTail(p); p->first_page = page; } @@ -285,7 +299,6 @@ static void destroy_compound_page(struct page *page, unsigned long order) { int i; int nr_pages = 1 << order; - struct page *p = page + 1; if (unlikely(compound_order(page) != order)) bad_page(page); @@ -293,9 +306,8 @@ static void destroy_compound_page(struct page *page, unsigned long order) if (unlikely(!PageHead(page))) bad_page(page); __ClearPageHead(page); - for (i = 1; i < nr_pages; i++, p++) { - if (unlikely((i & (MAX_ORDER_NR_PAGES - 1)) == 0)) - p = pfn_to_page(page_to_pfn(page) + i); + for (i = 1; i < nr_pages; i++) { + struct page *p = page + i; if (unlikely(!PageTail(p) | (p->first_page != page))) -- 1.6.0.1.451.gc8d31
| |