lkml.org 
[lkml]   [2013]   [Oct]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 05/11] pagemap: redefine callback functions for page table walker
Date
pagemap_pte_range() connected to pmd_entry() does both of pmd loop and
pte loop. So this patch moves pte part into pagemap_pte() on pte_entry().

We remove VM_SOFTDIRTY check in pagemap_pte_range(), because in the new
page table walker we call __walk_page_range() for each vma separately,
so we never experience multiple vmas in single pgd/pud/pmd/pte loop.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
---
fs/proc/task_mmu.c | 71 +++++++++++++++++++++---------------------------------
1 file changed, 27 insertions(+), 44 deletions(-)

diff --git v3.12-rc4.orig/fs/proc/task_mmu.c v3.12-rc4/fs/proc/task_mmu.c
index 4abe883..21e5828 100644
--- v3.12-rc4.orig/fs/proc/task_mmu.c
+++ v3.12-rc4/fs/proc/task_mmu.c
@@ -961,18 +961,32 @@ static inline void thp_pmd_to_pagemap_entry(pagemap_entry_t *pme, struct pagemap
}
#endif

-static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+static int pagemap_pte(pte_t *pte, 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;
- pte_t *pte;
+ pagemap_entry_t pme = make_pme(PM_NOT_PRESENT(pm->v2));
+
+ if (vma && vma->vm_start <= addr && end <= vma->vm_end) {
+ pte_to_pagemap_entry(&pme, pm, vma, addr, *pte);
+ /* unmap before userspace copy */
+ pte_unmap(pte);
+ }
+ return add_to_pagemap(addr, &pme, pm);
+}
+
+static int pagemap_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
+ struct mm_walk *walk)
+{
int err = 0;
+ struct vm_area_struct *vma = walk->vma;
+ struct pagemapread *pm = walk->private;
pagemap_entry_t pme = make_pme(PM_NOT_PRESENT(pm->v2));

- /* find the first VMA at or above 'addr' */
- vma = find_vma(walk->mm, addr);
- if (vma && pmd_trans_huge_lock(pmd, vma) == 1) {
+ if (!vma)
+ return err;
+ if (pmd_trans_huge_lock(pmd, vma) == 1) {
int pmd_flags2;

if ((vma->vm_flags & VM_SOFTDIRTY) || pmd_soft_dirty(*pmd))
@@ -991,41 +1005,9 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
break;
}
spin_unlock(&walk->mm->page_table_lock);
- return err;
- }
-
- 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));
- }
-
- /* 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);
- }
- err = add_to_pagemap(addr, &pme, pm);
- if (err)
- return err;
+ /* don't call pagemap_pte() */
+ walk->skip = 1;
}
-
- cond_resched();
-
return err;
}

@@ -1048,12 +1030,11 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
struct mm_walk *walk)
{
struct pagemapread *pm = walk->private;
- struct vm_area_struct *vma;
+ struct vm_area_struct *vma = walk->vma;
int err = 0;
int flags2;
pagemap_entry_t pme;

- vma = find_vma(walk->mm, addr);
WARN_ON_ONCE(!vma);

if (vma && (vma->vm_flags & VM_SOFTDIRTY))
@@ -1061,6 +1042,7 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
else
flags2 = 0;

+ hmask = huge_page_mask(hstate_vma(vma));
for (; addr != end; addr += PAGE_SIZE) {
int offset = (addr & ~hmask) >> PAGE_SHIFT;
huge_pte_to_pagemap_entry(&pme, pm, *pte, offset, flags2);
@@ -1137,10 +1119,11 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
if (!mm || IS_ERR(mm))
goto out_free;

- pagemap_walk.pmd_entry = pagemap_pte_range;
+ pagemap_walk.pte_entry = pagemap_pte;
+ pagemap_walk.pmd_entry = pagemap_pmd;
pagemap_walk.pte_hole = pagemap_pte_hole;
#ifdef CONFIG_HUGETLB_PAGE
- pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
+ pagemap_walk.hugetlb_entry = pagemap_hugetlb;
#endif
pagemap_walk.mm = mm;
pagemap_walk.private = &pm;
--
1.8.3.1


\
 
 \ /
  Last update: 2013-10-14 20:21    [W:0.104 / U:2.760 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site