Re: 2.4.7-ac4 disk thrashing

[Daniel Phillips]

On Wednesday 08 August 2001 12:57, Alan Cox wrote:
> > Could it be that the ReiserFS cleanups in ac4 do harm?
> > http://marc.theaimsgroup.com/?l=3Dreiserfs&m=3D99683332027428&w=3D2
>
> I suspect the use once patch is the more relevant one.

Two things to check:

  - Linus found a bug in balance_dirty_state yesterday.  Is the
    fix applied?

  - The original use-once patch tends to leave a referenced pages
    on the inactive_dirty queue longer, not in itself a problem,
    but can expose other problems.  The previously posted patch
    below fixes that, is it applied?

To apply (with use-once already applied):

  cd /usr/src/your.2.4.7.source.tree
  patch -p0 <this.patch

--- ../2.4.7.clean/mm/filemap.c	Sat Aug  4 14:27:16 2001
+++ ./mm/filemap.c	Sat Aug  4 23:41:00 2001
@@ -979,9 +979,13 @@
 
 static inline void check_used_once (struct page *page)
 {
-	if (!page->age) {
-		page->age = PAGE_AGE_START;
-		ClearPageReferenced(page);
+	if (!PageActive(page)) {
+		if (page->age)
+			activate_page(page);
+		else {
+			page->age = PAGE_AGE_START;
+			ClearPageReferenced(page);
+		}
 	}
 }