Re: [PATCH][1/2] adjust dirty threshold for lowmem-only mappings

[Andrew Morton <akpm@osdl.org>]

Rik van Riel <riel@redhat.com> wrote:
>
> Simply running "dd if=/dev/zero of=/dev/hd<one you can miss>" will
>  result in OOM kills, with the dirty pagecache completely filling up
>  lowmem.

That surely used to work - I have a feeling that it got broken somehow. 
The below might fix it, but probably not.

The intended behaviour is that the page-allocating process will throttle
and will then pick up those pages from the tail of the LRU which
rotate_reclaimable_page() put there.



We haven't been incrementing local variable total_scanned since the
scan_control stuff went in.  That broke kswapd throttling.

Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 25-akpm/mm/vmscan.c |    1 +
 1 files changed, 1 insertion(+)

diff -puN mm/vmscan.c~vmscan-total_scanned-fix mm/vmscan.c
--- 25/mm/vmscan.c~vmscan-total_scanned-fix	2004-12-20 12:47:25.855643408 -0800
+++ 25-akpm/mm/vmscan.c	2004-12-20 12:47:25.860642648 -0800
@@ -1063,6 +1063,7 @@ scan:
 			shrink_slab(sc.nr_scanned, GFP_KERNEL, lru_pages);
 			sc.nr_reclaimed += reclaim_state->reclaimed_slab;
 			total_reclaimed += sc.nr_reclaimed;
+			total_scanned += sc.nr_scanned;
 			if (zone->all_unreclaimable)
 				continue;
 			if (zone->pages_scanned >= (zone->nr_active +
_