Merge commit 'v2.6.37-rc8' into x86/apic

[pandora-kernel.git] / mm / ksm.c

diff --git a/mm/ksm.c b/mm/ksm.c
index e2ae004..43bc893 100644 (file)
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -712,7 +712,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
        if (!ptep)
                goto out;
 
-       if (pte_write(*ptep)) {
+       if (pte_write(*ptep) || pte_dirty(*ptep)) {
                pte_t entry;
 
                swapped = PageSwapCache(page);
@@ -735,7 +735,9 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
                        set_pte_at(mm, addr, ptep, entry);
                        goto out_unlock;
                }
-               entry = pte_wrprotect(entry);
+               if (pte_dirty(entry))
+                       set_page_dirty(page);
+               entry = pte_mkclean(pte_wrprotect(entry));
                set_pte_at_notify(mm, addr, ptep, entry);
        }
        *orig_pte = *ptep;
@@ -1504,8 +1506,6 @@ struct page *ksm_does_need_to_copy(struct page *page,
 {
        struct page *new_page;
 
-       unlock_page(page);      /* any racers will COW it, not modify it */
-
        new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
        if (new_page) {
                copy_user_highpage(new_page, page, address, vma);
@@ -1521,7 +1521,6 @@ struct page *ksm_does_need_to_copy(struct page *page,
                        add_page_to_unevictable_list(new_page);
        }
 
-       page_cache_release(page);
        return new_page;
 }
 
@@ -1725,8 +1724,13 @@ static int ksm_memory_callback(struct notifier_block *self,
                /*
                 * Keep it very simple for now: just lock out ksmd and
                 * MADV_UNMERGEABLE while any memory is going offline.
+                * mutex_lock_nested() is necessary because lockdep was alarmed
+                * that here we take ksm_thread_mutex inside notifier chain
+                * mutex, and later take notifier chain mutex inside
+                * ksm_thread_mutex to unlock it.   But that's safe because both
+                * are inside mem_hotplug_mutex.
                 */
-               mutex_lock(&ksm_thread_mutex);
+               mutex_lock_nested(&ksm_thread_mutex, SINGLE_DEPTH_NESTING);
                break;
 
        case MEM_OFFLINE: