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yaml
---
r: 198232
b: refs/heads/master
c: f488401
h: refs/heads/master
v: v3
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Johannes Weiner authored and Linus Torvalds committed May 25, 2010
1 parent 0b70a64 commit d6ebb72
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Showing 2 changed files with 98 additions and 75 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 6a60f1b3588aef6ddceaa14192df475d430cce45
refs/heads/master: f488401076c5570130c018e573f450a9a6c43365
171 changes: 97 additions & 74 deletions trunk/mm/mincore.c
Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,42 @@
#include <asm/uaccess.h>
#include <asm/pgtable.h>

static void mincore_hugetlb_page_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long nr,
unsigned char *vec)
{
#ifdef CONFIG_HUGETLB_PAGE
struct hstate *h;
int i;

i = 0;
h = hstate_vma(vma);
while (1) {
unsigned char present;
pte_t *ptep;
/*
* Huge pages are always in RAM for now, but
* theoretically it needs to be checked.
*/
ptep = huge_pte_offset(current->mm,
addr & huge_page_mask(h));
present = ptep && !huge_pte_none(huge_ptep_get(ptep));
while (1) {
vec[i++] = present;
addr += PAGE_SIZE;
/* reach buffer limit */
if (i == nr)
return;
/* check hugepage border */
if (!(addr & ~huge_page_mask(h)))
break;
}
}
#else
BUG();
#endif
}

/*
* Later we can get more picky about what "in core" means precisely.
* For now, simply check to see if the page is in the page cache,
Expand Down Expand Up @@ -49,6 +85,64 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff)
return present;
}

static void mincore_unmapped_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long nr,
unsigned char *vec)
{
int i;

if (vma->vm_file) {
pgoff_t pgoff;

pgoff = linear_page_index(vma, addr);
for (i = 0; i < nr; i++, pgoff++)
vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
} else {
for (i = 0; i < nr; i++)
vec[i] = 0;
}
}

static void mincore_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long nr,
unsigned char *vec)
{
spinlock_t *ptl;
pte_t *ptep;
int i;

ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
for (i = 0; i < nr; i++, ptep++, addr += PAGE_SIZE) {
pte_t pte = *ptep;
pgoff_t pgoff;

if (pte_none(pte))
mincore_unmapped_range(vma, addr, 1, vec);
else if (pte_present(pte))
vec[i] = 1;
else if (pte_file(pte)) {
pgoff = pte_to_pgoff(pte);
vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
} else { /* pte is a swap entry */
swp_entry_t entry = pte_to_swp_entry(pte);

if (is_migration_entry(entry)) {
/* migration entries are always uptodate */
vec[i] = 1;
} else {
#ifdef CONFIG_SWAP
pgoff = entry.val;
vec[i] = mincore_page(&swapper_space, pgoff);
#else
WARN_ON(1);
vec[i] = 1;
#endif
}
}
}
pte_unmap_unlock(ptep - 1, ptl);
}

/*
* Do a chunk of "sys_mincore()". We've already checked
* all the arguments, we hold the mmap semaphore: we should
Expand All @@ -59,11 +153,7 @@ static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *v
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *ptep;
spinlock_t *ptl;
unsigned long nr;
int i;
pgoff_t pgoff;
struct vm_area_struct *vma;

vma = find_vma(current->mm, addr);
Expand All @@ -72,35 +162,10 @@ static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *v

nr = min(pages, (vma->vm_end - addr) >> PAGE_SHIFT);

#ifdef CONFIG_HUGETLB_PAGE
if (is_vm_hugetlb_page(vma)) {
struct hstate *h;

i = 0;
h = hstate_vma(vma);
while (1) {
unsigned char present;
/*
* Huge pages are always in RAM for now, but
* theoretically it needs to be checked.
*/
ptep = huge_pte_offset(current->mm,
addr & huge_page_mask(h));
present = ptep && !huge_pte_none(huge_ptep_get(ptep));
while (1) {
vec[i++] = present;
addr += PAGE_SIZE;
/* reach buffer limit */
if (i == nr)
return nr;
/* check hugepage border */
if (!(addr & ~huge_page_mask(h)))
break;
}
}
mincore_hugetlb_page_range(vma, addr, nr, vec);
return nr;
}
#endif

/*
* Calculate how many pages there are left in the last level of the
Expand All @@ -118,53 +183,11 @@ static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *v
if (pmd_none_or_clear_bad(pmd))
goto none_mapped;

ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
for (i = 0; i < nr; i++, ptep++, addr += PAGE_SIZE) {
pte_t pte = *ptep;

if (pte_none(pte)) {
if (vma->vm_file) {
pgoff = linear_page_index(vma, addr);
vec[i] = mincore_page(vma->vm_file->f_mapping,
pgoff);
} else
vec[i] = 0;
} else if (pte_present(pte))
vec[i] = 1;
else if (pte_file(pte)) {
pgoff = pte_to_pgoff(pte);
vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
} else { /* pte is a swap entry */
swp_entry_t entry = pte_to_swp_entry(pte);

if (is_migration_entry(entry)) {
/* migration entries are always uptodate */
vec[i] = 1;
} else {
#ifdef CONFIG_SWAP
pgoff = entry.val;
vec[i] = mincore_page(&swapper_space, pgoff);
#else
WARN_ON(1);
vec[i] = 1;
#endif
}
}
}
pte_unmap_unlock(ptep - 1, ptl);

mincore_pte_range(vma, pmd, addr, nr, vec);
return nr;

none_mapped:
if (vma->vm_file) {
pgoff = linear_page_index(vma, addr);
for (i = 0; i < nr; i++, pgoff++)
vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
} else {
for (i = 0; i < nr; i++)
vec[i] = 0;
}

mincore_unmapped_range(vma, addr, nr, vec);
return nr;
}

Expand Down

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