Re: 2.6.23-mm1

Torsten Kaiser
2007-10-14T19:12:21Z

On 10/14/07, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Sun, 14 Oct 2007 13:54:26 +0200 "Torsten Kaiser" <just.for.lkml@googlemail.com> wrote:
>
> > > The page-owner code can pinpoint a leak source. See
> > > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.23/2.6.23-mm1/broken-out/page-owner-tracking-leak-detector.patch
> > >
> > > Enable CONFIG_DEBUG_SLAB_LEAK, check out /proc/slab_allocators
> >
> > Did that. The output of /proc/page_owner is ~350Mb, gzipped still ~7Mb.
> >
> > Taking only the first line from each stackdump it shows the following counts:
> >
> > ...
> >
> > 354042 [0xffffffff80266373] mempool_alloc+83
>
> This one is suspicious. Can you find the whole record for it?

I still have all 354042 records of it. ;)
The first column is the times I found this line in page_owner.
I divided the counts for the duplicate lines (mempool_alloc+83 and
kcryptd_do_crypt+0) by two, so normalize them. There still are some
false positive counts in there, so it does not match the 354042
precisely.

354036 Page allocated via order 0, mask 0x11202
1 (PFN/Block always differ) PFN 3072 Block 6 type 0 Flags
354338 [0xffffffff80266373] mempool_alloc+83
354338 [0xffffffff80266373] mempool_alloc+83
354025 [0xffffffff802bb389] bio_alloc_bioset+185
354058 [0xffffffff804d2b40] kcryptd_do_crypt+0
354052 [0xffffffff804d2cc7] kcryptd_do_crypt+391
354058 [0xffffffff804d2b40] kcryptd_do_crypt+0
354052 [0xffffffff80245d3c] run_workqueue+204
354062 [0xffffffff802467b0] worker_thread+0

I'm using dm-crypt with CONFIG_CRYPTO_TWOFISH_X86_64

> The other info shows a tremendous memory leak, not via slab. Looks like
> someone is running alloc_pages() directly and isnb't giving them back.

Blaming it on dm-crypt looks right, as the leak seems to happens, if
there is (heavy) disk activity.
(updatedb just ate ~500 Mb)

Torsten