Re: 2.6.10-rc3: kswapd eats CPU on start of memory-eating task

[Andrew Morton <akpm@osdl.org>]

Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
> On Sun, 2004-12-19 at 22:21 -0500, Rik van Riel wrote:
> > On Mon, 20 Dec 2004, Con Kolivas wrote:
> > 
> > > I still suspect the thrash token patch even with the swap token timeout 
> > > at 0. Is it completely disabled at 0 or does it still do something?
> > 
> > It makes it harder to page out pages from the task holding the
> > token.  I wonder if kswapd should try to steal the token away
> > from the task holding it, so in effect nobody holds the token
> > when the system isn't under a heavy swapping load.
> > 
> 
> In that case, the first thing we need to do is disable thrash token
> completely, and retest that. We still don't know for sure that it is
> the problem.
> 
> I don't have the code in front of me at the moment, but I'll be able
> to send a patch to do that in a couple of hours, if nobody beats me
> to it.

This should disable the thrashing control code?

--- 25/mm/rmap.c~a	2004-12-19 23:05:58.759420936 -0800
+++ 25-akpm/mm/rmap.c	2004-12-19 23:06:43.105679280 -0800
@@ -395,6 +395,8 @@ int page_referenced(struct page *page, i
 {
 	int referenced = 0;
 
+	ignore_token = 1;
+
 	if (page_test_and_clear_young(page))
 		referenced++;
 
_