Source: MontaVista Software, Inc., Steve Longerbeam <[email protected]>
Type: Enhancement
Disposition: merge to kernel.org
Acked-by: Andi Kleen <[email protected]>
Description:
Patches NUMA mempolicy to allow policies for file mappings. Also adds
a new mbind() flag that attempts to move existing anonymous and
filemap pages that do not satisfy a mapping's policy (MPOL_MF_MOVE).
Index: linux-2.6.9/fs/inode.c
===================================================================
--- linux-2.6.9.orig/fs/inode.c
+++ linux-2.6.9/fs/inode.c
@@ -150,6 +150,7 @@
mapping_set_gfp_mask(mapping, GFP_HIGHUSER);
mapping->assoc_mapping = NULL;
mapping->backing_dev_info = &default_backing_dev_info;
+ mpol_shared_policy_init(&mapping->policy);
/*
* If the block_device provides a backing_dev_info for client
@@ -177,8 +178,10 @@
security_inode_free(inode);
if (inode->i_sb->s_op->destroy_inode)
inode->i_sb->s_op->destroy_inode(inode);
- else
+ else {
+ mpol_free_shared_policy(&inode->i_mapping->policy);
kmem_cache_free(inode_cachep, (inode));
+ }
}
Index: linux-2.6.9/include/linux/fs.h
===================================================================
--- linux-2.6.9.orig/include/linux/fs.h
+++ linux-2.6.9/include/linux/fs.h
@@ -18,6 +18,7 @@
#include <linux/cache.h>
#include <linux/prio_tree.h>
#include <linux/kobject.h>
+#include <linux/mempolicy.h>
#include <asm/atomic.h>
struct iovec;
@@ -345,6 +346,7 @@
struct address_space_operations *a_ops; /* methods */
unsigned long flags; /* error bits/gfp mask */
struct backing_dev_info *backing_dev_info; /* device readahead, etc */
+ struct shared_policy policy; /* page alloc policy */
spinlock_t private_lock; /* for use by the address_space */
struct list_head private_list; /* ditto */
struct address_space *assoc_mapping; /* ditto */
Index: linux-2.6.9/include/linux/mempolicy.h
===================================================================
--- linux-2.6.9.orig/include/linux/mempolicy.h
+++ linux-2.6.9/include/linux/mempolicy.h
@@ -22,6 +22,8 @@
/* Flags for mbind */
#define MPOL_MF_STRICT (1<<0) /* Verify existing pages in the mapping */
+#define MPOL_MF_MOVE (1<<1) /* Attempt to move pages in mapping that do
+ not satisfy policy */
#ifdef __KERNEL__
@@ -149,7 +151,8 @@
void mpol_free_shared_policy(struct shared_policy *p);
struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
unsigned long idx);
-
+struct page *alloc_page_shared_policy(unsigned gfp, struct shared_policy *sp,
+ unsigned long idx);
extern void numa_default_policy(void);
extern void numa_policy_init(void);
@@ -215,6 +218,13 @@
#define vma_policy(vma) NULL
#define vma_set_policy(vma, pol) do {} while(0)
+static inline struct page *
+alloc_page_shared_policy(unsigned gfp, struct shared_policy *sp,
+ unsigned long idx)
+{
+ return alloc_pages(gfp, 0);
+}
+
static inline void numa_policy_init(void)
{
}
Index: linux-2.6.9/include/linux/page-flags.h
===================================================================
--- linux-2.6.9.orig/include/linux/page-flags.h
+++ linux-2.6.9/include/linux/page-flags.h
@@ -74,6 +74,8 @@
#define PG_swapcache 16 /* Swap page: swp_entry_t in private */
#define PG_mappedtodisk 17 /* Has blocks allocated on-disk */
#define PG_reclaim 18 /* To be reclaimed asap */
+#define PG_sharedpolicy 19 /* Page was allocated for a file
+ mapping using a shared_policy */
/*
@@ -290,6 +292,10 @@
#define SetPageCompound(page) set_bit(PG_compound, &(page)->flags)
#define ClearPageCompound(page) clear_bit(PG_compound, &(page)->flags)
+#define PageSharedPolicy(page) test_bit(PG_sharedpolicy, &(page)->flags)
+#define SetPageSharedPolicy(page) set_bit(PG_sharedpolicy, &(page)->flags)
+#define ClearPageSharedPolicy(page) clear_bit(PG_sharedpolicy, &(page)->flags)
+
#ifdef CONFIG_SWAP
#define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags)
#define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags)
Index: linux-2.6.9/include/linux/pagemap.h
===================================================================
--- linux-2.6.9.orig/include/linux/pagemap.h
+++ linux-2.6.9/include/linux/pagemap.h
@@ -50,14 +50,24 @@
#define page_cache_release(page) put_page(page)
void release_pages(struct page **pages, int nr, int cold);
-static inline struct page *page_cache_alloc(struct address_space *x)
+
+static inline struct page *__page_cache_alloc(struct address_space *x,
+ unsigned long idx,
+ unsigned int gfp_mask)
+{
+ return alloc_page_shared_policy(gfp_mask, &x->policy, idx);
+}
+
+static inline struct page *page_cache_alloc(struct address_space *x,
+ unsigned long idx)
{
- return alloc_pages(mapping_gfp_mask(x), 0);
+ return __page_cache_alloc(x, idx, mapping_gfp_mask(x));
}
-static inline struct page *page_cache_alloc_cold(struct address_space *x)
+static inline struct page *page_cache_alloc_cold(struct address_space *x,
+ unsigned long idx)
{
- return alloc_pages(mapping_gfp_mask(x)|__GFP_COLD, 0);
+ return __page_cache_alloc(x, idx, mapping_gfp_mask(x)|__GFP_COLD);
}
typedef int filler_t(void *, struct page *);
Index: linux-2.6.9/mm/filemap.c
===================================================================
--- linux-2.6.9.orig/mm/filemap.c
+++ linux-2.6.9/mm/filemap.c
@@ -595,7 +595,8 @@
page = find_lock_page(mapping, index);
if (!page) {
if (!cached_page) {
- cached_page = alloc_page(gfp_mask);
+ cached_page = __page_cache_alloc(mapping, index,
+ gfp_mask);
if (!cached_page)
return NULL;
}
@@ -688,7 +689,7 @@
return NULL;
}
gfp_mask = mapping_gfp_mask(mapping) & ~__GFP_FS;
- page = alloc_pages(gfp_mask, 0);
+ page = __page_cache_alloc(mapping, index, gfp_mask);
if (page && add_to_page_cache_lru(page, mapping, index, gfp_mask)) {
page_cache_release(page);
page = NULL;
@@ -865,7 +866,7 @@
* page..
*/
if (!cached_page) {
- cached_page = page_cache_alloc_cold(mapping);
+ cached_page = page_cache_alloc_cold(mapping, index);
if (!cached_page) {
desc->error = -ENOMEM;
goto out;
@@ -1128,7 +1129,7 @@
struct page *page;
int error;
- page = page_cache_alloc_cold(mapping);
+ page = page_cache_alloc_cold(mapping, offset);
if (!page)
return -ENOMEM;
@@ -1510,9 +1511,35 @@
return 0;
}
+
+#ifdef CONFIG_NUMA
+int generic_file_set_policy(struct vm_area_struct *vma,
+ struct mempolicy *new)
+{
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ return mpol_set_shared_policy(&mapping->policy, vma, new);
+}
+
+struct mempolicy *
+generic_file_get_policy(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ unsigned long idx;
+
+ idx = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+ return mpol_shared_policy_lookup(&mapping->policy, idx);
+}
+#endif
+
+
struct vm_operations_struct generic_file_vm_ops = {
.nopage = filemap_nopage,
.populate = filemap_populate,
+#ifdef CONFIG_NUMA
+ .set_policy = generic_file_set_policy,
+ .get_policy = generic_file_get_policy,
+#endif
};
/* This is used for a general mmap of a disk file */
@@ -1562,7 +1589,7 @@
page = find_get_page(mapping, index);
if (!page) {
if (!cached_page) {
- cached_page = page_cache_alloc_cold(mapping);
+ cached_page = page_cache_alloc_cold(mapping, index);
if (!cached_page)
return ERR_PTR(-ENOMEM);
}
@@ -1644,7 +1671,7 @@
page = find_lock_page(mapping, index);
if (!page) {
if (!*cached_page) {
- *cached_page = page_cache_alloc(mapping);
+ *cached_page = page_cache_alloc(mapping, index);
if (!*cached_page)
return NULL;
}
Index: linux-2.6.9/mm/mempolicy.c
===================================================================
--- linux-2.6.9.orig/mm/mempolicy.c
+++ linux-2.6.9/mm/mempolicy.c
@@ -66,6 +66,7 @@
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
+#include <linux/pagemap.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/string.h>
@@ -74,6 +75,9 @@
#include <linux/init.h>
#include <linux/compat.h>
#include <linux/mempolicy.h>
+#include <linux/rmap.h>
+#include <linux/swap.h>
+#include <asm/pgalloc.h>
#include <asm/uaccess.h>
static kmem_cache_t *policy_cache;
@@ -230,22 +234,220 @@
return policy;
}
-/* Ensure all existing pages follow the policy. */
+
+/* Return effective policy for a VMA */
+static struct mempolicy *
+get_vma_policy(struct vm_area_struct *vma, unsigned long addr)
+{
+ struct mempolicy *pol = current->mempolicy;
+
+ if (vma) {
+ if (vma->vm_ops && vma->vm_ops->get_policy)
+ pol = vma->vm_ops->get_policy(vma, addr);
+ else if (vma->vm_policy &&
+ vma->vm_policy->policy != MPOL_DEFAULT)
+ pol = vma->vm_policy;
+ }
+ if (!pol)
+ pol = &default_policy;
+ return pol;
+}
+
+
+/* Find secondary valid nodes for an allocation */
+static int __mpol_node_valid(int nid, struct mempolicy *pol)
+{
+ switch (pol->policy) {
+ case MPOL_PREFERRED:
+ case MPOL_DEFAULT:
+ case MPOL_INTERLEAVE:
+ return 1;
+ case MPOL_BIND: {
+ struct zone **z;
+ for (z = pol->v.zonelist->zones; *z; z++)
+ if ((*z)->zone_pgdat->node_id == nid)
+ return 1;
+ return 0;
+ }
+ default:
+ BUG();
+ return 0;
+ }
+}
+
+int mpol_node_valid(int nid, struct vm_area_struct *vma, unsigned long addr)
+{
+ return __mpol_node_valid(nid, get_vma_policy(vma, addr));
+}
+
+/*
+ * The given page doesn't match a file mapped VMA's policy. If the
+ * page is unused, remove it from the page cache, so that a new page
+ * can be later reallocated to the cache using the correct policy.
+ * Returns 0 if the page was removed from the cache, < 0 if failed.
+ *
+ * We use invalidate_mapping_pages(), which doesn't try very hard.
+ * It won't remove pages which are locked (won't wait for a lock),
+ * dirty, under writeback, or mapped by pte's. All the latter are
+ * valid checks for us, but we might be able to improve our success
+ * by waiting for a lock.
+ */
static int
-verify_pages(unsigned long addr, unsigned long end, unsigned long *nodes)
+remove_invalid_filemap_page(struct page * page,
+ struct vm_area_struct *vma,
+ pgoff_t pgoff)
+{
+ /*
+ * the page in the cache is not in any of the nodes this
+ * VMA's policy wants it to be in. Can we remove it?
+ */
+ if (!PageSharedPolicy(page) &&
+ invalidate_mapping_pages(vma->vm_file->f_mapping,
+ pgoff, pgoff) > 0) {
+ PDprintk("removed cache page in node %ld, "
+ "pgoff=%lu, for %s\n",
+ page_to_nid(page), pgoff,
+ vma->vm_file->f_dentry->d_name.name);
+ return 0;
+ }
+
+ /*
+ * the page is being used by other pagetable mappings,
+ * or is currently locked, dirty, or under writeback.
+ */
+ PDprintk("could not remove cache page in node %ld, "
+ "pgoff=%lu, for %s\n",
+ page_to_nid(page), pgoff,
+ vma->vm_file->f_dentry->d_name.name);
+ return -EIO;
+}
+
+/*
+ * The given page doesn't match a VMA's policy. Allocate a new
+ * page using the policy, copy contents from old to new, free
+ * the old page, map in the new page. This looks a lot like a COW.
+ */
+static int
+move_invalid_page(struct page * page, struct mempolicy *pol,
+ struct vm_area_struct *vma, unsigned long addr,
+ pmd_t *pmd)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ struct page * new_page;
+ struct vm_area_struct pvma;
+ pte_t *page_table;
+ pte_t entry;
+
+ PDprintk("moving anon page in node %ld, address=%08lx\n",
+ page_to_nid(page), addr);
+
+ if (!PageReserved(page))
+ page_cache_get(page);
+ spin_unlock(&mm->page_table_lock);
+ if (unlikely(anon_vma_prepare(vma)))
+ goto err_no_mem;
+
+ /* Create a pseudo vma that just contains the policy */
+ memset(&pvma, 0, sizeof(struct vm_area_struct));
+ pvma.vm_end = PAGE_SIZE;
+ pvma.vm_pgoff = vma->vm_pgoff;
+ pvma.vm_policy = pol;
+ new_page = alloc_page_vma(GFP_HIGHUSER, &pvma, addr);
+ if (!new_page)
+ goto err_no_mem;
+
+ copy_user_highpage(new_page, page, addr);
+
+ spin_lock(&mm->page_table_lock);
+ page_table = pte_offset_map(pmd, addr);
+ if (PageReserved(page))
+ ++mm->rss;
+ else
+ page_remove_rmap(page);
+
+ flush_cache_page(vma, addr);
+ entry = pte_mkdirty(mk_pte(new_page, vma->vm_page_prot));
+ if (likely(vma->vm_flags & VM_WRITE))
+ entry = pte_mkwrite(entry);
+ ptep_establish(vma, addr, page_table, entry);
+ update_mmu_cache(vma, addr, entry);
+ lru_cache_add_active(new_page);
+ page_add_anon_rmap(new_page, vma, addr);
+
+ pte_unmap(page_table);
+ page_cache_release(page); /* release our ref on the old page */
+ page_cache_release(page); /* release our pte ref on the old page */
+ return 0;
+
+ err_no_mem:
+ spin_lock(&mm->page_table_lock);
+ return -ENOMEM;
+}
+
+/* Ensure all existing pages in a VMA follow the policy. */
+static int
+move_verify_pages(struct vm_area_struct *vma, struct mempolicy *pol,
+ unsigned long flags)
{
- while (addr < end) {
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long addr;
+ unsigned long start = vma->vm_start;
+ unsigned long end = vma->vm_end;
+
+ if (!(flags & (MPOL_MF_MOVE | MPOL_MF_STRICT)))
+ return 0;
+
+ for (addr = start; addr < end; addr += PAGE_SIZE) {
struct page *p;
pte_t *pte;
pmd_t *pmd;
- pgd_t *pgd = pgd_offset_k(addr);
+ pgd_t *pgd;
+ int err;
+
+ /*
+ * first, if this is a file mapping and we are moving pages,
+ * check for invalid page cache pages, and if they are unused,
+ * remove.
+ */
+ if (vma->vm_ops && vma->vm_ops->nopage) {
+ struct address_space *mapping =
+ vma->vm_file->f_mapping;
+ unsigned long pgoff =
+ ((addr - vma->vm_start) >> PAGE_CACHE_SHIFT) +
+ vma->vm_pgoff;
+
+ p = find_get_page(mapping, pgoff);
+ if (p) {
+ err = 0;
+ if (!__mpol_node_valid(page_to_nid(p), pol)) {
+ if (!(flags & MPOL_MF_MOVE))
+ err = -EIO;
+ else
+ err = remove_invalid_filemap_page(
+ p,vma,pgoff);
+ }
+ page_cache_release(p); /* find_get_page */
+ if (err && (flags & MPOL_MF_STRICT))
+ return err;
+ }
+ }
+
+ /*
+ * Now let's see if there is a pte-mapped page that doesn't
+ * satisfy the policy. Because of the above, we can be sure
+ * from here that, if there is a VMA page that's pte-mapped
+ * and it belongs to the page cache, it either satisfies the
+ * policy, or we don't mind if it doesn't (MF_STRICT not set).
+ */
+ spin_lock(&mm->page_table_lock);
+ pgd = pgd_offset(mm, addr);
if (pgd_none(*pgd)) {
- addr = (addr + PGDIR_SIZE) & PGDIR_MASK;
+ spin_unlock(&mm->page_table_lock);
continue;
}
pmd = pmd_offset(pgd, addr);
if (pmd_none(*pmd)) {
- addr = (addr + PMD_SIZE) & PMD_MASK;
+ spin_unlock(&mm->page_table_lock);
continue;
}
p = NULL;
@@ -254,19 +456,29 @@
p = pte_page(*pte);
pte_unmap(pte);
if (p) {
- unsigned nid = page_to_nid(p);
- if (!test_bit(nid, nodes))
- return -EIO;
+ err = 0;
+ if (!__mpol_node_valid(page_to_nid(p), pol)) {
+ if (!(flags & MPOL_MF_MOVE))
+ err = -EIO;
+ else
+ err = move_invalid_page(p, pol, vma,
+ addr, pmd);
+ }
+ if (err && (flags & MPOL_MF_STRICT)) {
+ spin_unlock(&mm->page_table_lock);
+ return err;
+ }
}
- addr += PAGE_SIZE;
+ spin_unlock(&mm->page_table_lock);
}
+
return 0;
}
/* Step 1: check the range */
static struct vm_area_struct *
check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
- unsigned long *nodes, unsigned long flags)
+ struct mempolicy *policy, unsigned long flags)
{
int err;
struct vm_area_struct *first, *vma, *prev;
@@ -280,8 +492,8 @@
return ERR_PTR(-EFAULT);
if (prev && prev->vm_end < vma->vm_start)
return ERR_PTR(-EFAULT);
- if ((flags & MPOL_MF_STRICT) && !is_vm_hugetlb_page(vma)) {
- err = verify_pages(vma->vm_start, vma->vm_end, nodes);
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_STRICT)) {
+ err = move_verify_pages(vma, policy, flags);
if (err) {
first = ERR_PTR(err);
break;
@@ -348,12 +560,13 @@
DECLARE_BITMAP(nodes, MAX_NUMNODES);
int err;
- if ((flags & ~(unsigned long)(MPOL_MF_STRICT)) || mode > MPOL_MAX)
+ if ((flags & ~(unsigned long)(MPOL_MF_STRICT | MPOL_MF_MOVE)) ||
+ mode > MPOL_MAX)
return -EINVAL;
if (start & ~PAGE_MASK)
return -EINVAL;
if (mode == MPOL_DEFAULT)
- flags &= ~MPOL_MF_STRICT;
+ flags &= ~(MPOL_MF_STRICT | MPOL_MF_MOVE);
len = (len + PAGE_SIZE - 1) & PAGE_MASK;
end = start + len;
if (end < start)
@@ -373,7 +586,7 @@
mode,nodes[0]);
down_write(&mm->mmap_sem);
- vma = check_range(mm, start, end, nodes, flags);
+ vma = check_range(mm, start, end, new, flags);
err = PTR_ERR(vma);
if (!IS_ERR(vma))
err = mbind_range(vma, start, end, new);
@@ -606,24 +819,6 @@
#endif
-/* Return effective policy for a VMA */
-static struct mempolicy *
-get_vma_policy(struct vm_area_struct *vma, unsigned long addr)
-{
- struct mempolicy *pol = current->mempolicy;
-
- if (vma) {
- if (vma->vm_ops && vma->vm_ops->get_policy)
- pol = vma->vm_ops->get_policy(vma, addr);
- else if (vma->vm_policy &&
- vma->vm_policy->policy != MPOL_DEFAULT)
- pol = vma->vm_policy;
- }
- if (!pol)
- pol = &default_policy;
- return pol;
-}
-
/* Return a zonelist representing a mempolicy */
static struct zonelist *zonelist_policy(unsigned gfp, struct mempolicy *policy)
{
@@ -858,28 +1053,6 @@
return 0;
}
-/* Find secondary valid nodes for an allocation */
-int mpol_node_valid(int nid, struct vm_area_struct *vma, unsigned long addr)
-{
- struct mempolicy *pol = get_vma_policy(vma, addr);
-
- switch (pol->policy) {
- case MPOL_PREFERRED:
- case MPOL_DEFAULT:
- case MPOL_INTERLEAVE:
- return 1;
- case MPOL_BIND: {
- struct zone **z;
- for (z = pol->v.zonelist->zones; *z; z++)
- if ((*z)->zone_pgdat->node_id == nid)
- return 1;
- return 0;
- }
- default:
- BUG();
- return 0;
- }
-}
/*
* Shared memory backing store policy support.
@@ -996,10 +1169,14 @@
/* Take care of old policies in the same range. */
while (n && n->start < end) {
struct rb_node *next = rb_next(&n->nd);
- if (n->start >= start) {
- if (n->end <= end)
+ if (n->start == start && n->end == end &&
+ mpol_equal(n->policy, new->policy)) {
+ /* the same shared policy already exists, just exit */
+ goto out;
+ } else if (n->start >= start) {
+ if (n->end <= end) {
sp_delete(sp, n);
- else
+ } else
n->start = end;
} else {
/* Old policy spanning whole new range. */
@@ -1022,6 +1199,7 @@
}
if (new)
sp_insert(sp, new);
+ out:
up(&sp->sem);
return 0;
}
@@ -1067,6 +1245,37 @@
up(&p->sem);
}
+struct page *
+alloc_page_shared_policy(unsigned gfp, struct shared_policy *sp,
+ unsigned long idx)
+{
+ struct page *page;
+ struct mempolicy * shared_pol = NULL;
+
+ if (sp->root.rb_node) {
+ struct vm_area_struct pvma;
+ /* Create a pseudo vma that just contains the policy */
+ memset(&pvma, 0, sizeof(struct vm_area_struct));
+ pvma.vm_end = PAGE_SIZE;
+ pvma.vm_pgoff = idx;
+ shared_pol = mpol_shared_policy_lookup(sp, idx);
+ pvma.vm_policy = shared_pol;
+ page = alloc_page_vma(gfp, &pvma, 0);
+ mpol_free(pvma.vm_policy);
+ } else {
+ page = alloc_pages(gfp, 0);
+ }
+
+ if (page) {
+ if (shared_pol)
+ SetPageSharedPolicy(page);
+ else
+ ClearPageSharedPolicy(page);
+ }
+
+ return page;
+}
+
/* assumes fs == KERNEL_DS */
void __init numa_policy_init(void)
{
Index: linux-2.6.9/mm/readahead.c
===================================================================
--- linux-2.6.9.orig/mm/readahead.c
+++ linux-2.6.9/mm/readahead.c
@@ -245,7 +245,7 @@
continue;
spin_unlock_irq(&mapping->tree_lock);
- page = page_cache_alloc_cold(mapping);
+ page = page_cache_alloc_cold(mapping, page_offset);
spin_lock_irq(&mapping->tree_lock);
if (!page)
break;
Index: linux-2.6.9/mm/shmem.c
===================================================================
--- linux-2.6.9.orig/mm/shmem.c
+++ linux-2.6.9/mm/shmem.c
@@ -841,16 +841,7 @@
shmem_alloc_page(unsigned long gfp, struct shmem_inode_info *info,
unsigned long idx)
{
- struct vm_area_struct pvma;
- struct page *page;
-
- memset(&pvma, 0, sizeof(struct vm_area_struct));
- pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx);
- pvma.vm_pgoff = idx;
- pvma.vm_end = PAGE_SIZE;
- page = alloc_page_vma(gfp, &pvma, 0);
- mpol_free(pvma.vm_policy);
- return page;
+ return alloc_page_shared_policy(gfp, &info->policy, idx);
}
#else
static inline struct page *