[PATCH 1/4] mempolicies: private pointer in check_range and MPOL_MF_INVERT

From: Christoph Lameter
Date: Mon Nov 21 2005 - 15:43:05 EST


[PATCH] memory policies: Genericize check_range()

This was was first posted at
http://marc.theaimsgroup.com/?l=linux-mm&m=113149240227584&w=2

(Part of this functionality is also contained in the direct migration
pathset. The functionality here is more generic and independent of that
patchset.)

- Add internal flags MPOL_MF_INVERT to control check_range() behavior.

- Replace the pagelist passed through by check_range by a general
private pointer that may be used for other purposes.
(The following patches will use that to merge numa_maps into
mempolicy.c and to better group the page migration code in
the policy layer)

- Improve some comments.

Signed-off-by: Christoph Lameter <clameter@xxxxxxx>

Index: linux-2.6.15-rc1-mm2/mm/mempolicy.c
===================================================================
--- linux-2.6.15-rc1-mm2.orig/mm/mempolicy.c 2005-11-21 10:51:46.000000000 -0800
+++ linux-2.6.15-rc1-mm2/mm/mempolicy.c 2005-11-21 12:02:32.000000000 -0800
@@ -88,8 +88,9 @@
#include <asm/tlbflush.h>
#include <asm/uaccess.h>

-/* Internal MPOL_MF_xxx flags */
+/* Internal flags */
#define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0) /* Skip checks for continuous vmas */
+#define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1) /* Invert check for nodemask */

static kmem_cache_t *policy_cache;
static kmem_cache_t *sn_cache;
@@ -232,11 +233,11 @@ static void migrate_page_add(struct vm_a
}
}

-/* Ensure all existing pages follow the policy. */
+/* Scan through pages checking if pages follow certain conditions. */
static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
- struct list_head *pagelist)
+ void *private)
{
pte_t *orig_pte;
pte_t *pte;
@@ -246,6 +247,7 @@ static int check_pte_range(struct vm_are
do {
unsigned long pfn;
unsigned int nid;
+ struct page *page;

if (!pte_present(*pte))
continue;
@@ -254,15 +256,16 @@ static int check_pte_range(struct vm_are
print_bad_pte(vma, *pte, addr);
continue;
}
- nid = pfn_to_nid(pfn);
- if (!node_isset(nid, *nodes)) {
- if (pagelist) {
- struct page *page = pfn_to_page(pfn);
+ page = pfn_to_page(pfn);
+ nid = page_to_nid(page);
+ if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
+ continue;
+
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
+ migrate_page_add(vma, page, private, flags);
+ else
+ break;

- migrate_page_add(vma, page, pagelist, flags);
- } else
- break;
- }
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_unmap_unlock(orig_pte, ptl);
return addr != end;
@@ -271,7 +274,7 @@ static int check_pte_range(struct vm_are
static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
- struct list_head *pagelist)
+ void *private)
{
pmd_t *pmd;
unsigned long next;
@@ -282,7 +285,7 @@ static inline int check_pmd_range(struct
if (pmd_none_or_clear_bad(pmd))
continue;
if (check_pte_range(vma, pmd, addr, next, nodes,
- flags, pagelist))
+ flags, private))
return -EIO;
} while (pmd++, addr = next, addr != end);
return 0;
@@ -291,7 +294,7 @@ static inline int check_pmd_range(struct
static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
- struct list_head *pagelist)
+ void *private)
{
pud_t *pud;
unsigned long next;
@@ -302,7 +305,7 @@ static inline int check_pud_range(struct
if (pud_none_or_clear_bad(pud))
continue;
if (check_pmd_range(vma, pud, addr, next, nodes,
- flags, pagelist))
+ flags, private))
return -EIO;
} while (pud++, addr = next, addr != end);
return 0;
@@ -311,7 +314,7 @@ static inline int check_pud_range(struct
static inline int check_pgd_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end,
const nodemask_t *nodes, unsigned long flags,
- struct list_head *pagelist)
+ void *private)
{
pgd_t *pgd;
unsigned long next;
@@ -322,7 +325,7 @@ static inline int check_pgd_range(struct
if (pgd_none_or_clear_bad(pgd))
continue;
if (check_pud_range(vma, pgd, addr, next, nodes,
- flags, pagelist))
+ flags, private))
return -EIO;
} while (pgd++, addr = next, addr != end);
return 0;
@@ -344,7 +347,7 @@ static inline int vma_migratable(struct
*/
static struct vm_area_struct *
check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
- const nodemask_t *nodes, unsigned long flags, struct list_head *pagelist)
+ const nodemask_t *nodes, unsigned long flags, void *private)
{
int err;
struct vm_area_struct *first, *vma, *prev;
@@ -373,7 +376,7 @@ check_range(struct mm_struct *mm, unsign
if (vma->vm_start > start)
start = vma->vm_start;
err = check_pgd_range(vma, start, endvma, nodes,
- flags, pagelist);
+ flags, private);
if (err) {
first = ERR_PTR(err);
break;
@@ -461,7 +464,8 @@ long do_mbind(unsigned long start, unsig
int err;
LIST_HEAD(pagelist);

- if ((flags & ~(unsigned long)(MPOL_MF_STRICT|MPOL_MF_MOVE|MPOL_MF_MOVE_ALL))
+ 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))
@@ -499,8 +503,9 @@ long do_mbind(unsigned long start, unsig
mode,nodes_addr(nodes)[0]);

down_write(&mm->mmap_sem);
- vma = check_range(mm, start, end, nmask, flags,
- (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) ? &pagelist : NULL);
+ vma = check_range(mm, start, end, nmask,
+ flags | MPOL_MF_INVERT, &pagelist);
+
err = PTR_ERR(vma);
if (!IS_ERR(vma)) {
int nr_failed = 0;
@@ -655,7 +660,6 @@ int do_migrate_pages(struct mm_struct *m
nodemask_t nodes;

nodes_andnot(nodes, *from_nodes, *to_nodes);
- nodes_complement(nodes, nodes);

down_read(&mm->mmap_sem);
check_range(mm, mm->mmap->vm_start, TASK_SIZE, &nodes,
-
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