Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / mm / page-writeback.c

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index b4edfe7ce06c1bf5f6d692235eac4e07f9068490..2cb01f6ec5d019e7e431d9f18cdba6f3bde573e4 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -404,15 +404,18 @@ unsigned long determine_dirtyable_memory(void)
  * - vm.dirty_background_ratio  or  vm.dirty_background_bytes
  * - vm.dirty_ratio             or  vm.dirty_bytes
  * The dirty limits will be lifted by 1/4 for PF_LESS_THROTTLE (ie. nfsd) and
- * runtime tasks.
+ * real-time tasks.
  */
 void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty)
 {
        unsigned long background;
        unsigned long dirty;
-       unsigned long available_memory = determine_dirtyable_memory();
+       unsigned long uninitialized_var(available_memory);
        struct task_struct *tsk;
 
+       if (!vm_dirty_bytes || !dirty_background_bytes)
+               available_memory = determine_dirtyable_memory();
+
        if (vm_dirty_bytes)
                dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE);
        else
@@ -1103,7 +1106,7 @@ EXPORT_SYMBOL(write_one_page);
 int __set_page_dirty_no_writeback(struct page *page)
 {
        if (!PageDirty(page))
-               SetPageDirty(page);
+               return !TestSetPageDirty(page);
        return 0;
 }