From: Rik van Riel Date: Tue, 10 Aug 2010 00:19:48 +0000 (-0700) Subject: rmap: add exclusive page to private anon_vma on swapin X-Git-Tag: v2.6.36-rc1~403 X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=commitdiff_plain;h=ad8c2ee801ad7a52d919b478d9b2c7b39a72d295 rmap: add exclusive page to private anon_vma on swapin On swapin it is fairly common for a page to be owned exclusively by one process. In that case we want to add the page to the anon_vma of that process's VMA, instead of to the root anon_vma. This will reduce the amount of rmap searching that the swapout code needs to do. Signed-off-by: Rik van Riel Cc: Andrea Arcangeli Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/rmap.h b/include/linux/rmap.h index dc9b3c0bf5d4..d6661de56f30 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -162,6 +162,8 @@ static inline void anon_vma_merge(struct vm_area_struct *vma, */ void page_move_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); +void do_page_add_anon_rmap(struct page *, struct vm_area_struct *, + unsigned long, int); void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long); void page_add_file_rmap(struct page *); void page_remove_rmap(struct page *); diff --git a/mm/memory.c b/mm/memory.c index 6b0c37dcfd16..6bc039486e9f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2628,6 +2628,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, swp_entry_t entry; pte_t pte; struct mem_cgroup *ptr = NULL; + int exclusive = 0; int ret = 0; if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) @@ -2722,10 +2723,11 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) { pte = maybe_mkwrite(pte_mkdirty(pte), vma); flags &= ~FAULT_FLAG_WRITE; + exclusive = 1; } flush_icache_page(vma, page); set_pte_at(mm, address, page_table, pte); - page_add_anon_rmap(page, vma, address); + do_page_add_anon_rmap(page, vma, address, exclusive); /* It's better to call commit-charge after rmap is established */ mem_cgroup_commit_charge_swapin(page, ptr); diff --git a/mm/rmap.c b/mm/rmap.c index 4d152a6d3a89..a7d0f5482634 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -829,6 +829,17 @@ static void __page_check_anon_rmap(struct page *page, */ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address) +{ + do_page_add_anon_rmap(page, vma, address, 0); +} + +/* + * Special version of the above for do_swap_page, which often runs + * into pages that are exclusively owned by the current process. + * Everybody else should continue to use page_add_anon_rmap above. + */ +void do_page_add_anon_rmap(struct page *page, + struct vm_area_struct *vma, unsigned long address, int exclusive) { int first = atomic_inc_and_test(&page->_mapcount); if (first) @@ -839,7 +850,7 @@ void page_add_anon_rmap(struct page *page, VM_BUG_ON(!PageLocked(page)); VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end); if (first) - __page_set_anon_rmap(page, vma, address, 0); + __page_set_anon_rmap(page, vma, address, exclusive); else __page_check_anon_rmap(page, vma, address); }