Skip to content

Commit

Permalink
[PATCH] Move page migration related functions near do_migrate_pages()
Browse files Browse the repository at this point in the history 
Group page migration functions in mempolicy.c

Add a forward declaration for migrate_page_add (like gather_stats()) and use
our new found mobility to group all page migration related function around
do_migrate_pages().

Signed-off-by: Christoph Lameter <[email protected]>
Cc: Andi Kleen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
  • Loading branch information
Christoph Lameter authored and Linus Torvalds committed Jan 9, 2006
1 parent 48fce34 commit 6ce3c4c
Showing 1 changed file with 138 additions and 132 deletions.
270 changes: 138 additions & 132 deletions mm/mempolicy.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -183,55 +183,9 @@ static struct mempolicy *mpol_new(int mode, nodemask_t *nodes)
return policy;
}

/* Check if we are the only process mapping the page in question */
static inline int single_mm_mapping(struct mm_struct *mm,
struct address_space *mapping)
{
struct vm_area_struct *vma;
struct prio_tree_iter iter;
int rc = 1;

spin_lock(&mapping->i_mmap_lock);
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX)
if (mm != vma->vm_mm) {
rc = 0;
goto out;
}
list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list)
if (mm != vma->vm_mm) {
rc = 0;
goto out;
}
out:
spin_unlock(&mapping->i_mmap_lock);
return rc;
}

/*
* Add a page to be migrated to the pagelist
*/
static void migrate_page_add(struct vm_area_struct *vma,
struct page *page, struct list_head *pagelist, unsigned long flags)
{
/*
* Avoid migrating a page that is shared by others and not writable.
*/
if ((flags & MPOL_MF_MOVE_ALL) || !page->mapping || PageAnon(page) ||
mapping_writably_mapped(page->mapping) ||
single_mm_mapping(vma->vm_mm, page->mapping)) {
int rc = isolate_lru_page(page);

if (rc == 1)
list_add(&page->lru, pagelist);
/*
* If the isolate attempt was not successful then we just
* encountered an unswappable page. Something must be wrong.
*/
WARN_ON(rc == 0);
}
}

static void gather_stats(struct page *, void *);
static void migrate_page_add(struct vm_area_struct *vma,
struct page *page, struct list_head *pagelist, unsigned long flags);

/* Scan through pages checking if pages follow certain conditions. */
static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
Expand Down Expand Up @@ -440,90 +394,6 @@ static int contextualize_policy(int mode, nodemask_t *nodes)
return mpol_check_policy(mode, nodes);
}

static int swap_pages(struct list_head *pagelist)
{
LIST_HEAD(moved);
LIST_HEAD(failed);
int n;

n = migrate_pages(pagelist, NULL, &moved, &failed);
putback_lru_pages(&failed);
putback_lru_pages(&moved);

return n;
}

long do_mbind(unsigned long start, unsigned long len,
unsigned long mode, nodemask_t *nmask, unsigned long flags)
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
struct mempolicy *new;
unsigned long end;
int err;
LIST_HEAD(pagelist);

if ((flags & ~(unsigned long)(MPOL_MF_STRICT |
MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
|| mode > MPOL_MAX)
return -EINVAL;
if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_RESOURCE))
return -EPERM;

if (start & ~PAGE_MASK)
return -EINVAL;

if (mode == MPOL_DEFAULT)
flags &= ~MPOL_MF_STRICT;

len = (len + PAGE_SIZE - 1) & PAGE_MASK;
end = start + len;

if (end < start)
return -EINVAL;
if (end == start)
return 0;

if (mpol_check_policy(mode, nmask))
return -EINVAL;

new = mpol_new(mode, nmask);
if (IS_ERR(new))
return PTR_ERR(new);

/*
* If we are using the default policy then operation
* on discontinuous address spaces is okay after all
*/
if (!new)
flags |= MPOL_MF_DISCONTIG_OK;

PDprintk("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len,
mode,nodes_addr(nodes)[0]);

down_write(&mm->mmap_sem);
vma = check_range(mm, start, end, nmask,
flags | MPOL_MF_INVERT, &pagelist);

err = PTR_ERR(vma);
if (!IS_ERR(vma)) {
int nr_failed = 0;

err = mbind_range(vma, start, end, new);
if (!list_empty(&pagelist))
nr_failed = swap_pages(&pagelist);

if (!err && nr_failed && (flags & MPOL_MF_STRICT))
err = -EIO;
}
if (!list_empty(&pagelist))
putback_lru_pages(&pagelist);

up_write(&mm->mmap_sem);
mpol_free(new);
return err;
}

/* Set the process memory policy */
long do_set_mempolicy(int mode, nodemask_t *nodes)
{
Expand Down Expand Up @@ -643,6 +513,71 @@ long do_get_mempolicy(int *policy, nodemask_t *nmask,
return err;
}

/*
* page migration
*/

/* Check if we are the only process mapping the page in question */
static inline int single_mm_mapping(struct mm_struct *mm,
struct address_space *mapping)
{
struct vm_area_struct *vma;
struct prio_tree_iter iter;
int rc = 1;

spin_lock(&mapping->i_mmap_lock);
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX)
if (mm != vma->vm_mm) {
rc = 0;
goto out;
}
list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list)
if (mm != vma->vm_mm) {
rc = 0;
goto out;
}
out:
spin_unlock(&mapping->i_mmap_lock);
return rc;
}

/*
* Add a page to be migrated to the pagelist
*/
static void migrate_page_add(struct vm_area_struct *vma,
struct page *page, struct list_head *pagelist, unsigned long flags)
{
/*
* Avoid migrating a page that is shared by others and not writable.
*/
if ((flags & MPOL_MF_MOVE_ALL) || !page->mapping || PageAnon(page) ||
mapping_writably_mapped(page->mapping) ||
single_mm_mapping(vma->vm_mm, page->mapping)) {
int rc = isolate_lru_page(page);

if (rc == 1)
list_add(&page->lru, pagelist);
/*
* If the isolate attempt was not successful then we just
* encountered an unswappable page. Something must be wrong.
*/
WARN_ON(rc == 0);
}
}

static int swap_pages(struct list_head *pagelist)
{
LIST_HEAD(moved);
LIST_HEAD(failed);
int n;

n = migrate_pages(pagelist, NULL, &moved, &failed);
putback_lru_pages(&failed);
putback_lru_pages(&moved);

return n;
}

/*
* For now migrate_pages simply swaps out the pages from nodes that are in
* the source set but not in the target set. In the future, we would
Expand Down Expand Up @@ -673,6 +608,77 @@ int do_migrate_pages(struct mm_struct *mm,
return count;
}

long do_mbind(unsigned long start, unsigned long len,
unsigned long mode, nodemask_t *nmask, unsigned long flags)
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
struct mempolicy *new;
unsigned long end;
int err;
LIST_HEAD(pagelist);

if ((flags & ~(unsigned long)(MPOL_MF_STRICT |
MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
|| mode > MPOL_MAX)
return -EINVAL;
if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_RESOURCE))
return -EPERM;

if (start & ~PAGE_MASK)
return -EINVAL;

if (mode == MPOL_DEFAULT)
flags &= ~MPOL_MF_STRICT;

len = (len + PAGE_SIZE - 1) & PAGE_MASK;
end = start + len;

if (end < start)
return -EINVAL;
if (end == start)
return 0;

if (mpol_check_policy(mode, nmask))
return -EINVAL;

new = mpol_new(mode, nmask);
if (IS_ERR(new))
return PTR_ERR(new);

/*
* If we are using the default policy then operation
* on discontinuous address spaces is okay after all
*/
if (!new)
flags |= MPOL_MF_DISCONTIG_OK;

PDprintk("mbind %lx-%lx mode:%ld nodes:%lx\n",start,start+len,
mode,nodes_addr(nodes)[0]);

down_write(&mm->mmap_sem);
vma = check_range(mm, start, end, nmask,
flags | MPOL_MF_INVERT, &pagelist);

err = PTR_ERR(vma);
if (!IS_ERR(vma)) {
int nr_failed = 0;

err = mbind_range(vma, start, end, new);
if (!list_empty(&pagelist))
nr_failed = swap_pages(&pagelist);

if (!err && nr_failed && (flags & MPOL_MF_STRICT))
err = -EIO;
}
if (!list_empty(&pagelist))
putback_lru_pages(&pagelist);

up_write(&mm->mmap_sem);
mpol_free(new);
return err;
}

/*
* User space interface with variable sized bitmaps for nodelists.
*/
Expand Down

0 comments on commit 6ce3c4c

Please sign in to comment.