Commit 6ce3c4c0 authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

[PATCH] Move page migration related functions near do_migrate_pages()



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: default avatarChristoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 48fce342
......@@ -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,
......@@ -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)
{
......@@ -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
......@@ -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.
*/
......
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