These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / Documentation / vm / page_migration

diff --git a/kernel/Documentation/vm/page_migration b/kernel/Documentation/vm/page_migration
index 6513fe2..fea5c08 100644 (file)
--- a/kernel/Documentation/vm/page_migration
+++ b/kernel/Documentation/vm/page_migration
@@ -92,29 +92,26 @@ Steps:
 
 2. Insure that writeback is complete.
 
-3. Prep the new page that we want to move to. It is locked
-   and set to not being uptodate so that all accesses to the new
-   page immediately lock while the move is in progress.
+3. Lock the new page that we want to move to. It is locked so that accesses to
+   this (not yet uptodate) page immediately lock while the move is in progress.
 
-4. The new page is prepped with some settings from the old page so that
-   accesses to the new page will discover a page with the correct settings.
-
-5. All the page table references to the page are converted
-   to migration entries or dropped (nonlinear vmas).
-   This decrease the mapcount of a page. If the resulting
-   mapcount is not zero then we do not migrate the page.
-   All user space processes that attempt to access the page
-   will now wait on the page lock.
+4. All the page table references to the page are converted to migration
+   entries. This decreases the mapcount of a page. If the resulting
+   mapcount is not zero then we do not migrate the page. All user space
+   processes that attempt to access the page will now wait on the page lock.
 
-6. The radix tree lock is taken. This will cause all processes trying
+5. The radix tree lock is taken. This will cause all processes trying
    to access the page via the mapping to block on the radix tree spinlock.
 
-7. The refcount of the page is examined and we back out if references remain
+6. The refcount of the page is examined and we back out if references remain
    otherwise we know that we are the only one referencing this page.
 
-8. The radix tree is checked and if it does not contain the pointer to this
+7. The radix tree is checked and if it does not contain the pointer to this
    page then we back out because someone else modified the radix tree.
 
+8. The new page is prepped with some settings from the old page so that
+   accesses to the new page will discover a page with the correct settings.
+
 9. The radix tree is changed to point to the new page.
 
 10. The reference count of the old page is dropped because the radix tree