return new_page;
}
-int page_referenced_ksm(struct page *page, struct mem_cgroup *memcg,
- unsigned long *vm_flags)
+int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc)
{
struct stable_node *stable_node;
struct rmap_item *rmap_item;
- unsigned int mapcount = page_mapcount(page);
- int referenced = 0;
+ int ret = SWAP_AGAIN;
int search_new_forks = 0;
- VM_BUG_ON(!PageKsm(page));
- VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON_PAGE(!PageKsm(page), page);
+
+ /*
+ * Rely on the page lock to protect against concurrent modifications
+ * to that page's node of the stable tree.
+ */
+ VM_BUG_ON_PAGE(!PageLocked(page), page);
stable_node = page_stable_node(page);
if (!stable_node)
- return 0;
+ return ret;
again:
hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {
struct anon_vma *anon_vma = rmap_item->anon_vma;
if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
continue;
- if (memcg && !mm_match_cgroup(vma->vm_mm, memcg))
- continue;
-
- referenced += page_referenced_one(page, vma,
- rmap_item->address, &mapcount, vm_flags);
- if (!search_new_forks || !mapcount)
- break;
- }
- anon_vma_unlock_read(anon_vma);
- if (!mapcount)
- goto out;
- }
- if (!search_new_forks++)
- goto again;
-out:
- return referenced;
-}
-
-int try_to_unmap_ksm(struct page *page, enum ttu_flags flags)
-{
- struct stable_node *stable_node;
- struct rmap_item *rmap_item;
- int ret = SWAP_AGAIN;
- int search_new_forks = 0;
-
- VM_BUG_ON(!PageKsm(page));
- VM_BUG_ON(!PageLocked(page));
-
- stable_node = page_stable_node(page);
- if (!stable_node)
- return SWAP_FAIL;
-again:
- hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {
- struct anon_vma *anon_vma = rmap_item->anon_vma;
- struct anon_vma_chain *vmac;
- struct vm_area_struct *vma;
-
- anon_vma_lock_read(anon_vma);
- anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root,
- 0, ULONG_MAX) {
- vma = vmac->vma;
- if (rmap_item->address < vma->vm_start ||
- rmap_item->address >= vma->vm_end)
- continue;
- /*
- * Initially we examine only the vma which covers this
- * rmap_item; but later, if there is still work to do,
- * we examine covering vmas in other mms: in case they
- * were forked from the original since ksmd passed.
- */
- if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
+ if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
continue;
- ret = try_to_unmap_one(page, vma,
- rmap_item->address, flags);
- if (ret != SWAP_AGAIN || !page_mapped(page)) {
+ ret = rwc->rmap_one(page, vma,
+ rmap_item->address, rwc->arg);
+ if (ret != SWAP_AGAIN) {
anon_vma_unlock_read(anon_vma);
goto out;
}
- }
- anon_vma_unlock_read(anon_vma);
- }
- if (!search_new_forks++)
- goto again;
-out:
- return ret;
-}
-
-#ifdef CONFIG_MIGRATION
-int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page *,
- struct vm_area_struct *, unsigned long, void *), void *arg)
-{
- struct stable_node *stable_node;
- struct rmap_item *rmap_item;
- int ret = SWAP_AGAIN;
- int search_new_forks = 0;
-
- VM_BUG_ON(!PageKsm(page));
- VM_BUG_ON(!PageLocked(page));
-
- stable_node = page_stable_node(page);
- if (!stable_node)
- return ret;
-again:
- hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {
- struct anon_vma *anon_vma = rmap_item->anon_vma;
- struct anon_vma_chain *vmac;
- struct vm_area_struct *vma;
-
- anon_vma_lock_read(anon_vma);
- anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root,
- 0, ULONG_MAX) {
- vma = vmac->vma;
- if (rmap_item->address < vma->vm_start ||
- rmap_item->address >= vma->vm_end)
- continue;
- /*
- * Initially we examine only the vma which covers this
- * rmap_item; but later, if there is still work to do,
- * we examine covering vmas in other mms: in case they
- * were forked from the original since ksmd passed.
- */
- if ((rmap_item->mm == vma->vm_mm) == search_new_forks)
- continue;
-
- ret = rmap_one(page, vma, rmap_item->address, arg);
- if (ret != SWAP_AGAIN) {
+ if (rwc->done && rwc->done(page)) {
anon_vma_unlock_read(anon_vma);
goto out;
}
return ret;
}
+#ifdef CONFIG_MIGRATION
void ksm_migrate_page(struct page *newpage, struct page *oldpage)
{
struct stable_node *stable_node;
- VM_BUG_ON(!PageLocked(oldpage));
- VM_BUG_ON(!PageLocked(newpage));
- VM_BUG_ON(newpage->mapping != oldpage->mapping);
+ VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
+ VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
+ VM_BUG_ON_PAGE(newpage->mapping != oldpage->mapping, newpage);
stable_node = page_stable_node(newpage);
if (stable_node) {
- VM_BUG_ON(stable_node->kpfn != page_to_pfn(oldpage));
+ VM_BUG_ON_PAGE(stable_node->kpfn != page_to_pfn(oldpage), oldpage);
stable_node->kpfn = page_to_pfn(newpage);
/*
* newpage->mapping was set in advance; now we need smp_wmb()
projects / karo-tx-linux.git / blobdiff