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thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page()

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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 <kirill.shutemov@linux.intel.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kirill A. Shutemov 2013-09-12 15:14:05 -07:00 committed by Linus Torvalds
parent 128ec037ba
commit c02925540c
4 changed files with 13 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/linux/huge_mm.h
View File

@ -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)
{

3
include/linux/mm.h
View File

@ -877,11 +877,12 @@ 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)

31
mm/huge_memory.c
View File

@ -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,

9
mm/memory.c
View File

@ -3695,7 +3695,7 @@ 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)
{
@ -3774,9 +3774,12 @@ 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;