From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qa0-f43.google.com (mail-qa0-f43.google.com [209.85.216.43]) by kanga.kvack.org (Postfix) with ESMTP id D9BD76B0035 for ; Wed, 6 Aug 2014 15:14:42 -0400 (EDT) Received: by mail-qa0-f43.google.com with SMTP id w8so2955133qac.16 for ; Wed, 06 Aug 2014 12:14:41 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id u63si3109384qgd.68.2014.08.06.12.14.40 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 06 Aug 2014 12:14:41 -0700 (PDT) Date: Wed, 6 Aug 2014 15:14:30 -0400 From: Naoya Horiguchi Subject: Re: [PATCH -mm v6 06/13] pagemap: use walk->vma instead of calling find_vma() Message-ID: <20140806191430.GA19526@nhori.bos.redhat.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> <20140806173040.GA28526@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140806173040.GA28526@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: Peter Feiner Cc: Andrew Morton , Dave Hansen , Hugh Dickins , "Kirill A. Shutemov" , Jerome Marchand , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi Hi Peter, On Wed, Aug 06, 2014 at 01:30:40PM -0400, Peter Feiner wrote: > 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: Thanks for the comment. > --- > 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)); > - } Right. Soft dirty check is done in pte_to_pagemap_entry(), and vma boundary check is done in mm/pagewalk.c, so we don't need this block any more. Thanks, Naoya Horiguchi > - > - /* 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 > > -- > 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/ . > Don't email: email@kvack.org > -- 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/ . Don't email: email@kvack.org