Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753368AbaBJVsa (ORCPT ); Mon, 10 Feb 2014 16:48:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41807 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752256AbaBJVpd (ORCPT ); Mon, 10 Feb 2014 16:45:33 -0500 From: Naoya Horiguchi To: linux-mm@kvack.org Cc: Andrew Morton , Matt Mackall , Cliff Wickman , KOSAKI Motohiro , Johannes Weiner , KAMEZAWA Hiroyuki , Michal Hocko , "Aneesh Kumar K.V" , Pavel Emelyanov , Rik van Riel , kirill.shutemov@linux.intel.com, linux-kernel@vger.kernel.org Subject: [PATCH 04/11] clear_refs: redefine callback functions for page table walker Date: Mon, 10 Feb 2014 16:44:29 -0500 Message-Id: <1392068676-30627-5-git-send-email-n-horiguchi@ah.jp.nec.com> In-Reply-To: <1392068676-30627-1-git-send-email-n-horiguchi@ah.jp.nec.com> References: <1392068676-30627-1-git-send-email-n-horiguchi@ah.jp.nec.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently clear_refs_pte_range() is connected to pmd_entry() to split thps if found. But now this work can be done in core page table walker code. So we have no reason to keep this callback on pmd_entry(). This patch moves pte handling code on pte_entry() callback. clear_refs_write() has some prechecks about if we really walk over a given vma. It's fine to let them done by test_walk() callback, so let's define it. Signed-off-by: Naoya Horiguchi --- fs/proc/task_mmu.c | 82 ++++++++++++++++++++++-------------------------------- 1 file changed, 33 insertions(+), 49 deletions(-) diff --git v3.14-rc2.orig/fs/proc/task_mmu.c v3.14-rc2/fs/proc/task_mmu.c index 62eedbe50733..8ecae2f55a97 100644 --- v3.14-rc2.orig/fs/proc/task_mmu.c +++ v3.14-rc2/fs/proc/task_mmu.c @@ -698,7 +698,6 @@ enum clear_refs_types { }; struct clear_refs_private { - struct vm_area_struct *vma; enum clear_refs_types type; }; @@ -730,41 +729,43 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma, #endif } -static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, +static int clear_refs_pte(pte_t *pte, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct clear_refs_private *cp = walk->private; - struct vm_area_struct *vma = cp->vma; - pte_t *pte, ptent; - spinlock_t *ptl; + struct vm_area_struct *vma = walk->vma; struct page *page; - split_huge_page_pmd(vma, addr, pmd); - if (pmd_trans_unstable(pmd)) + if (cp->type == CLEAR_REFS_SOFT_DIRTY) { + clear_soft_dirty(vma, addr, pte); return 0; + } + if (!pte_present(*pte)) + return 0; + page = vm_normal_page(vma, addr, *pte); + if (!page) + return 0; + /* Clear accessed and referenced bits. */ + ptep_test_and_clear_young(vma, addr, pte); + ClearPageReferenced(page); + return 0; +} - pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); - for (; addr != end; pte++, addr += PAGE_SIZE) { - ptent = *pte; - - if (cp->type == CLEAR_REFS_SOFT_DIRTY) { - clear_soft_dirty(vma, addr, pte); - continue; - } - - if (!pte_present(ptent)) - continue; - - page = vm_normal_page(vma, addr, ptent); - if (!page) - continue; +static int clear_refs_test_walk(unsigned long start, unsigned long end, + struct mm_walk *walk) +{ + struct clear_refs_private *cp = walk->private; + struct vm_area_struct *vma = walk->vma; - /* Clear accessed and referenced bits. */ - ptep_test_and_clear_young(vma, addr, pte); - ClearPageReferenced(page); - } - pte_unmap_unlock(pte - 1, ptl); - cond_resched(); + /* + * Writing 1 to /proc/pid/clear_refs affects all pages. + * Writing 2 to /proc/pid/clear_refs only affects anonymous pages. + * Writing 3 to /proc/pid/clear_refs only affects file mapped pages. + */ + if (cp->type == CLEAR_REFS_ANON && vma->vm_file) + walk->skip = 1; + if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file) + walk->skip = 1; return 0; } @@ -806,33 +807,16 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, .type = type, }; struct mm_walk clear_refs_walk = { - .pmd_entry = clear_refs_pte_range, + .pte_entry = clear_refs_pte, + .test_walk = clear_refs_test_walk, .mm = mm, .private = &cp, }; down_read(&mm->mmap_sem); if (type == CLEAR_REFS_SOFT_DIRTY) mmu_notifier_invalidate_range_start(mm, 0, -1); - for (vma = mm->mmap; vma; vma = vma->vm_next) { - cp.vma = vma; - if (is_vm_hugetlb_page(vma)) - continue; - /* - * Writing 1 to /proc/pid/clear_refs affects all pages. - * - * Writing 2 to /proc/pid/clear_refs only affects - * Anonymous pages. - * - * Writing 3 to /proc/pid/clear_refs only affects file - * mapped pages. - */ - if (type == CLEAR_REFS_ANON && vma->vm_file) - continue; - if (type == CLEAR_REFS_MAPPED && !vma->vm_file) - continue; - walk_page_range(vma->vm_start, vma->vm_end, - &clear_refs_walk); - } + for (vma = mm->mmap; vma; vma = vma->vm_next) + walk_page_vma(vma, &clear_refs_walk); if (type == CLEAR_REFS_SOFT_DIRTY) mmu_notifier_invalidate_range_end(mm, 0, -1); flush_tlb_mm(mm); -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/