From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id BE7D96B03E6 for ; Fri, 18 Nov 2016 04:19:32 -0500 (EST) Received: by mail-wm0-f70.google.com with SMTP id w13so9684050wmw.0 for ; Fri, 18 Nov 2016 01:19:32 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id lr1si6717062wjb.36.2016.11.18.01.17.30 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 18 Nov 2016 01:17:30 -0800 (PST) From: Jan Kara Subject: [PATCH 13/20] mm: Use vmf->page during WP faults Date: Fri, 18 Nov 2016 10:17:17 +0100 Message-Id: <1479460644-25076-14-git-send-email-jack@suse.cz> In-Reply-To: <1479460644-25076-1-git-send-email-jack@suse.cz> References: <1479460644-25076-1-git-send-email-jack@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: "Kirill A. Shutemov" , Ross Zwisler , Andrew Morton , linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, Jan Kara So far we set vmf->page during WP faults only when we needed to pass it to the ->page_mkwrite handler. Set it in all the cases now and use that instead of passing page pointer explicitly around. Acked-by: Kirill A. Shutemov Reviewed-by: Ross Zwisler Signed-off-by: Jan Kara --- mm/memory.c | 58 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 29 insertions(+), 29 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 6d4e1b1cea51..8d08015ed44d 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2106,11 +2106,12 @@ static void fault_dirty_shared_page(struct vm_area_struct *vma, * case, all we need to do here is to mark the page as writable and update * any related book-keeping. */ -static inline int wp_page_reuse(struct vm_fault *vmf, struct page *page, +static inline int wp_page_reuse(struct vm_fault *vmf, int page_mkwrite, int dirty_shared) __releases(vmf->ptl) { struct vm_area_struct *vma = vmf->vma; + struct page *page = vmf->page; pte_t entry; /* * Clear the pages cpupid information as the existing @@ -2154,10 +2155,11 @@ static inline int wp_page_reuse(struct vm_fault *vmf, struct page *page, * held to the old page, as well as updating the rmap. * - In any case, unlock the PTL and drop the reference we took to the old page. */ -static int wp_page_copy(struct vm_fault *vmf, struct page *old_page) +static int wp_page_copy(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct mm_struct *mm = vma->vm_mm; + struct page *old_page = vmf->page; struct page *new_page = NULL; pte_t entry; int page_copied = 0; @@ -2309,26 +2311,25 @@ static int wp_pfn_shared(struct vm_fault *vmf) return 0; } } - return wp_page_reuse(vmf, NULL, 0, 0); + return wp_page_reuse(vmf, 0, 0); } -static int wp_page_shared(struct vm_fault *vmf, struct page *old_page) +static int wp_page_shared(struct vm_fault *vmf) __releases(vmf->ptl) { struct vm_area_struct *vma = vmf->vma; int page_mkwrite = 0; - get_page(old_page); + get_page(vmf->page); if (vma->vm_ops && vma->vm_ops->page_mkwrite) { int tmp; pte_unmap_unlock(vmf->pte, vmf->ptl); - vmf->page = old_page; tmp = do_page_mkwrite(vmf); if (unlikely(!tmp || (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { - put_page(old_page); + put_page(vmf->page); return tmp; } /* @@ -2340,15 +2341,15 @@ static int wp_page_shared(struct vm_fault *vmf, struct page *old_page) vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); if (!pte_same(*vmf->pte, vmf->orig_pte)) { - unlock_page(old_page); + unlock_page(vmf->page); pte_unmap_unlock(vmf->pte, vmf->ptl); - put_page(old_page); + put_page(vmf->page); return 0; } page_mkwrite = 1; } - return wp_page_reuse(vmf, old_page, page_mkwrite, 1); + return wp_page_reuse(vmf, page_mkwrite, 1); } /* @@ -2373,10 +2374,9 @@ static int do_wp_page(struct vm_fault *vmf) __releases(vmf->ptl) { struct vm_area_struct *vma = vmf->vma; - struct page *old_page; - old_page = vm_normal_page(vma, vmf->address, vmf->orig_pte); - if (!old_page) { + vmf->page = vm_normal_page(vma, vmf->address, vmf->orig_pte); + if (!vmf->page) { /* * VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a * VM_PFNMAP VMA. @@ -2389,30 +2389,30 @@ static int do_wp_page(struct vm_fault *vmf) return wp_pfn_shared(vmf); pte_unmap_unlock(vmf->pte, vmf->ptl); - return wp_page_copy(vmf, old_page); + return wp_page_copy(vmf); } /* * Take out anonymous pages first, anonymous shared vmas are * not dirty accountable. */ - if (PageAnon(old_page) && !PageKsm(old_page)) { + if (PageAnon(vmf->page) && !PageKsm(vmf->page)) { int total_mapcount; - if (!trylock_page(old_page)) { - get_page(old_page); + if (!trylock_page(vmf->page)) { + get_page(vmf->page); pte_unmap_unlock(vmf->pte, vmf->ptl); - lock_page(old_page); + lock_page(vmf->page); vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); if (!pte_same(*vmf->pte, vmf->orig_pte)) { - unlock_page(old_page); + unlock_page(vmf->page); pte_unmap_unlock(vmf->pte, vmf->ptl); - put_page(old_page); + put_page(vmf->page); return 0; } - put_page(old_page); + put_page(vmf->page); } - if (reuse_swap_page(old_page, &total_mapcount)) { + if (reuse_swap_page(vmf->page, &total_mapcount)) { if (total_mapcount == 1) { /* * The page is all ours. Move it to @@ -2421,24 +2421,24 @@ static int do_wp_page(struct vm_fault *vmf) * Protected against the rmap code by * the page lock. */ - page_move_anon_rmap(old_page, vma); + page_move_anon_rmap(vmf->page, vma); } - unlock_page(old_page); - return wp_page_reuse(vmf, old_page, 0, 0); + unlock_page(vmf->page); + return wp_page_reuse(vmf, 0, 0); } - unlock_page(old_page); + unlock_page(vmf->page); } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED))) { - return wp_page_shared(vmf, old_page); + return wp_page_shared(vmf); } /* * Ok, we need to copy. Oh, well.. */ - get_page(old_page); + get_page(vmf->page); pte_unmap_unlock(vmf->pte, vmf->ptl); - return wp_page_copy(vmf, old_page); + return wp_page_copy(vmf); } static void unmap_mapping_range_vma(struct vm_area_struct *vma, -- 2.6.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . 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