diff options
Diffstat (limited to 'mm/ksm.c')
| -rw-r--r-- | mm/ksm.c | 65 |
1 files changed, 65 insertions, 0 deletions
@@ -1656,6 +1656,71 @@ 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 hlist_node *hlist; + 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, hlist, &stable_node->hlist, hlist) { + struct anon_vma *anon_vma = rmap_item->anon_vma; + struct vm_area_struct *vma; + + spin_lock(&anon_vma->lock); + list_for_each_entry(vma, &anon_vma->head, anon_vma_node) { + 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) { + spin_unlock(&anon_vma->lock); + goto out; + } + } + spin_unlock(&anon_vma->lock); + } + if (!search_new_forks++) + goto again; +out: + return ret; +} + +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); + + stable_node = page_stable_node(newpage); + if (stable_node) { + VM_BUG_ON(stable_node->page != oldpage); + stable_node->page = newpage; + } +} +#endif /* CONFIG_MIGRATION */ + #ifdef CONFIG_SYSFS /* * This all compiles without CONFIG_SYSFS, but is a waste of space. |