From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752860Ab0F3Phi (ORCPT ); Wed, 30 Jun 2010 11:37:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9766 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751582Ab0F3Phh (ORCPT ); Wed, 30 Jun 2010 11:37:37 -0400 Date: Wed, 30 Jun 2010 11:37:10 -0400 From: Rik van Riel To: akpm@linux-foundation.org Cc: aarcange@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kosaki.motohiro@jp.fujitsu.com Subject: [PATCH -mm] rmap: add exclusive page to private anon_vma on swapin Message-ID: <20100630113710.3b376e6a@annuminas.surriel.com> Organization: Red Hat, Inc. Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 369bdb4..31b2fd7 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 119b7cc..c0d984c 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2620,6 +2620,7 @@ 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)) @@ -2714,10 +2715,11 @@ 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 73d497e..a129679 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -831,6 +831,17 @@ 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) __inc_zone_page_state(page, NR_ANON_PAGES); @@ -840,7 +851,7 @@ 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); }