Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966734AbaFTUMT (ORCPT ); Fri, 20 Jun 2014 16:12:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38283 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751731AbaFTUMK (ORCPT ); Fri, 20 Jun 2014 16:12:10 -0400 From: Naoya Horiguchi To: linux-mm@kvack.org Cc: Andrew Morton , Dave Hansen , Hugh Dickins , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, Naoya Horiguchi Subject: [PATCH v3 01/13] mm/pagewalk: remove pgd_entry() and pud_entry() Date: Fri, 20 Jun 2014 16:11:27 -0400 Message-Id: <1403295099-6407-2-git-send-email-n-horiguchi@ah.jp.nec.com> In-Reply-To: <1403295099-6407-1-git-send-email-n-horiguchi@ah.jp.nec.com> References: <1403295099-6407-1-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 no user of page table walker sets ->pgd_entry() or ->pud_entry(), so checking their existence in each loop is just wasting CPU cycle. So let's remove it to reduce overhead. Signed-off-by: Naoya Horiguchi --- include/linux/mm.h | 6 ------ mm/pagewalk.c | 9 ++------- 2 files changed, 2 insertions(+), 13 deletions(-) diff --git v3.16-rc1.orig/include/linux/mm.h v3.16-rc1/include/linux/mm.h index e03dd29145a0..c5cb6394e6cb 100644 --- v3.16-rc1.orig/include/linux/mm.h +++ v3.16-rc1/include/linux/mm.h @@ -1100,8 +1100,6 @@ void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma, /** * mm_walk - callbacks for walk_page_range - * @pgd_entry: if set, called for each non-empty PGD (top-level) entry - * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry * this handler is required to be able to handle * pmd_trans_huge() pmds. They may simply choose to @@ -1115,10 +1113,6 @@ void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma, * (see walk_page_range for more details) */ struct mm_walk { - int (*pgd_entry)(pgd_t *pgd, unsigned long addr, - unsigned long next, struct mm_walk *walk); - int (*pud_entry)(pud_t *pud, unsigned long addr, - unsigned long next, struct mm_walk *walk); int (*pmd_entry)(pmd_t *pmd, unsigned long addr, unsigned long next, struct mm_walk *walk); int (*pte_entry)(pte_t *pte, unsigned long addr, diff --git v3.16-rc1.orig/mm/pagewalk.c v3.16-rc1/mm/pagewalk.c index 2beeabf502c5..335690650b12 100644 --- v3.16-rc1.orig/mm/pagewalk.c +++ v3.16-rc1/mm/pagewalk.c @@ -86,9 +86,7 @@ static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end, break; continue; } - if (walk->pud_entry) - err = walk->pud_entry(pud, addr, next, walk); - if (!err && (walk->pmd_entry || walk->pte_entry)) + if (walk->pmd_entry || walk->pte_entry) err = walk_pmd_range(pud, addr, next, walk); if (err) break; @@ -234,10 +232,7 @@ int walk_page_range(unsigned long addr, unsigned long end, pgd++; continue; } - if (walk->pgd_entry) - err = walk->pgd_entry(pgd, addr, next, walk); - if (!err && - (walk->pud_entry || walk->pmd_entry || walk->pte_entry)) + if (walk->pmd_entry || walk->pte_entry) err = walk_pud_range(pgd, addr, next, walk); if (err) break; -- 1.9.3 -- 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/