From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754143AbaHFRxV (ORCPT ); Wed, 6 Aug 2014 13:53:21 -0400 Received: from mail-yh0-f74.google.com ([209.85.213.74]:41460 "EHLO mail-yh0-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754047AbaHFRxS (ORCPT ); Wed, 6 Aug 2014 13:53:18 -0400 Date: Wed, 6 Aug 2014 13:30:40 -0400 From: Peter Feiner To: Naoya Horiguchi Cc: Andrew Morton , Dave Hansen , Hugh Dickins , "Kirill A. Shutemov" , Jerome Marchand , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi Subject: Re: [PATCH -mm v6 06/13] pagemap: use walk->vma instead of calling find_vma() Message-ID: <20140806173040.GA28526@google.com> References: <1406920849-25908-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1406920849-25908-7-git-send-email-n-horiguchi@ah.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1406920849-25908-7-git-send-email-n-horiguchi@ah.jp.nec.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 01, 2014 at 03:20:42PM -0400, Naoya Horiguchi wrote: > Page table walker has the information of the current vma in mm_walk, so > we don't have to call find_vma() in each pagemap_hugetlb_range() call. You could also get rid of a bunch of code in pagemap_pte_range: --- fs/proc/task_mmu.c | 33 ++++++--------------------------- 1 file changed, 6 insertions(+), 27 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 9b30bdd..e9af130 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1035,16 +1035,14 @@ static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemap static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { - struct vm_area_struct *vma; + struct vm_area_struct *vma = walk->vma struct pagemapread *pm = walk->private; spinlock_t *ptl; pte_t *pte; int err = 0; - pagemap_entry_t pme = make_pme(PM_NOT_PRESENT(pm->v2)); + pagemap_entry_t pme; - /* find the first VMA at or above 'addr' */ - vma = find_vma(walk->mm, addr); - if (vma && pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { + if (pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { int pmd_flags2; if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(*pmd)) @@ -1069,28 +1067,9 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, if (pmd_trans_unstable(pmd)) return 0; for (; addr != end; addr += PAGE_SIZE) { - int flags2; - - /* check to see if we've left 'vma' behind - * and need a new, higher one */ - if (vma && (addr >= vma->vm_end)) { - vma = find_vma(walk->mm, addr); - if (vma && (vma->vm_flags & VM_SOFTDIRTY)) - flags2 = __PM_SOFT_DIRTY; - else - flags2 = 0; - pme = make_pme(PM_NOT_PRESENT(pm->v2) | PM_STATUS2(pm->v2, flags2)); - } - - /* check that 'vma' actually covers this address, - * and that it isn't a huge page vma */ - if (vma && (vma->vm_start <= addr) && - !is_vm_hugetlb_page(vma)) { - pte = pte_offset_map(pmd, addr); - pte_to_pagemap_entry(&pme, pm, vma, addr, *pte); - /* unmap before userspace copy */ - pte_unmap(pte); - } + pte = pte_offset_map(pmd, addr); + pte_to_pagemap_entry(&pme, pm, vma, addr, *pte); + pte_unmap(pte); err = add_to_pagemap(addr, &pme, pm); if (err) return err; -- 2.0.0.526.g5318336