Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755484Ab3GOKpO (ORCPT ); Mon, 15 Jul 2013 06:45:14 -0400 Received: from mga09.intel.com ([134.134.136.24]:49141 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755405Ab3GOKpI (ORCPT ); Mon, 15 Jul 2013 06:45:08 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,668,1367996400"; d="scan'208";a="345744647" From: "Kirill A. Shutemov" To: Andrea Arcangeli , Andrew Morton Cc: Al Viro , Hugh Dickins , Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , Hillf Danton , Dave Hansen , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH 8/8] thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page() Date: Mon, 15 Jul 2013 13:47:54 +0300 Message-Id: <1373885274-25249-9-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1373885274-25249-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1373885274-25249-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5674 Lines: 154 From: "Kirill A. Shutemov" do_huge_pmd_anonymous_page() has copy-pasted piece of handle_mm_fault() to handle fallback path. Let's consolidate code back by introducing VM_FAULT_FALLBACK return code. Signed-off-by: Kirill A. Shutemov Acked-by: Hillf Danton --- include/linux/huge_mm.h | 3 --- include/linux/mm.h | 3 ++- mm/huge_memory.c | 31 +++++-------------------------- mm/memory.c | 9 ++++++--- 4 files changed, 13 insertions(+), 33 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index b60de92..3935428 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -96,9 +96,6 @@ extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma, unsigned long addr, unsigned long end); -extern int handle_pte_fault(struct mm_struct *mm, - struct vm_area_struct *vma, unsigned long address, - pte_t *pte, pmd_t *pmd, unsigned int flags); extern int split_huge_page_to_list(struct page *page, struct list_head *list); static inline int split_huge_page(struct page *page) { diff --git a/include/linux/mm.h b/include/linux/mm.h index f022460..d5c82dc 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -884,11 +884,12 @@ static inline int page_mapped(struct page *page) #define VM_FAULT_NOPAGE 0x0100 /* ->fault installed the pte, not return page */ #define VM_FAULT_LOCKED 0x0200 /* ->fault locked the returned page */ #define VM_FAULT_RETRY 0x0400 /* ->fault blocked, must retry */ +#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */ #define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */ #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \ - VM_FAULT_HWPOISON_LARGE) + VM_FAULT_FALLBACK | VM_FAULT_HWPOISON_LARGE) /* Encode hstate index for a hwpoisoned large page */ #define VM_FAULT_SET_HINDEX(x) ((x) << 12) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 82f0697..c3b8c9c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -783,10 +783,9 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, { struct page *page; unsigned long haddr = address & HPAGE_PMD_MASK; - pte_t *pte; if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end) - goto out; + return VM_FAULT_FALLBACK; if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM; if (unlikely(khugepaged_enter(vma))) @@ -803,7 +802,7 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, if (unlikely(!zero_page)) { pte_free(mm, pgtable); count_vm_event(THP_FAULT_FALLBACK); - goto out; + return VM_FAULT_FALLBACK; } spin_lock(&mm->page_table_lock); set = set_huge_zero_page(pgtable, mm, vma, haddr, pmd, @@ -819,40 +818,20 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, vma, haddr, numa_node_id(), 0); if (unlikely(!page)) { count_vm_event(THP_FAULT_FALLBACK); - goto out; + return VM_FAULT_FALLBACK; } count_vm_event(THP_FAULT_ALLOC); if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) { put_page(page); - goto out; + return VM_FAULT_FALLBACK; } if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page))) { mem_cgroup_uncharge_page(page); put_page(page); - goto out; + return VM_FAULT_FALLBACK; } return 0; -out: - /* - * Use __pte_alloc instead of pte_alloc_map, because we can't - * run pte_offset_map on the pmd, if an huge pmd could - * materialize from under us from a different thread. - */ - if (unlikely(pmd_none(*pmd)) && - unlikely(__pte_alloc(mm, vma, pmd, address))) - return VM_FAULT_OOM; - /* if an huge pmd materialized from under us just retry later */ - if (unlikely(pmd_trans_huge(*pmd))) - return 0; - /* - * A regular pmd is established and it can't morph into a huge pmd - * from under us anymore at this point because we hold the mmap_sem - * read mode and khugepaged takes it in write mode. So now it's - * safe to run pte_offset_map(). - */ - pte = pte_offset_map(pmd, address); - return handle_pte_fault(mm, vma, address, pte, pmd, flags); } int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, diff --git a/mm/memory.c b/mm/memory.c index 1ce2e2a..f2ab2a8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3693,7 +3693,7 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, * but allow concurrent faults), and pte mapped but not yet locked. * We return with mmap_sem still held, but pte unmapped and unlocked. */ -int handle_pte_fault(struct mm_struct *mm, +static int handle_pte_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *pte, pmd_t *pmd, unsigned int flags) { @@ -3780,9 +3780,12 @@ retry: if (!pmd) return VM_FAULT_OOM; if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) { + int ret = VM_FAULT_FALLBACK; if (!vma->vm_ops) - return do_huge_pmd_anonymous_page(mm, vma, address, - pmd, flags); + ret = do_huge_pmd_anonymous_page(mm, vma, address, + pmd, flags); + if (!(ret & VM_FAULT_FALLBACK)) + return ret; } else { pmd_t orig_pmd = *pmd; int ret; -- 1.8.3.2 -- 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/