Re: Possible dcache BUG

[Nick Piggin]

Udo A. Steinberg wrote:
> On Fri, 20 Aug 2004 00:11:54 -0700 Andrew Morton (AM) wrote:
>
> AM> "Udo A. Steinberg" <us15@xxxxxxxxxxxxxxxxxxxx> wrote:
> AM> >
> AM> > I've tried to download 700 MB of data from a digital camera via USB using
> AM> >  "gphoto2 --get-all-files" and I can repeatedly run my 128 MB box out of
> AM> >  memory using either Linux 2.4.26 or 2.6.8.1 for that.
> AM> 
> AM> whee.  How much swap is online?
>
> Something close to 512 MB.
>
> Adding 506512k swap on /dev/hda2.  Priority:-1 extents:1
>
> AM> Not that it matters - you seem to have a bunch of reclaimable pagecache
> AM> just sitting there.  Very odd.
> AM> 
> AM> Could gphoto2 be using mlock?  Does it run as root?
>
> No, gphoto2 was not running as root.
>
> -Udo.

Can you reproduce the OOM with the following patch please? Then
send the output.

Thanks




---

 linux-2.6-npiggin/mm/page_alloc.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletion(-)

diff -puN mm/page_alloc.c~vm-unreclaimable-debug mm/page_alloc.c
--- linux-2.6/mm/page_alloc.c~vm-unreclaimable-debug	2004-08-20 17:44:45.000000000 +1000
+++ linux-2.6-npiggin/mm/page_alloc.c	2004-08-20 17:48:26.000000000 +1000
@@ -1182,6 +1182,8 @@ void show_free_areas(void)
 			" active:%lukB"
 			" inactive:%lukB"
 			" present:%lukB"
+			" pages_scanned:%lu"
+			" all_unreclaimable? %s"
 			"\n",
 			zone->name,
 			K(zone->free_pages),
@@ -1190,7 +1192,9 @@ void show_free_areas(void)
 			K(zone->pages_high),
 			K(zone->nr_active),
 			K(zone->nr_inactive),
-			K(zone->present_pages)
+			K(zone->present_pages),
+			zone->pages_scanned,
+			(zone->all_unreclaimable ? "yes" : "no")
 			);
 		printk("protections[]:");
 		for (i = 0; i < MAX_NR_ZONES; i++)

_