Re: 2.6.16-mm1 leaks in dvb playback

[Andrew Morton <akpm@osdl.org>]

Adrian Bridgett <adrian@smop.co.uk> wrote:
>
> I've had this problem for a little while (probably since 2.6.14/15
> era) but I've only recently spent some time to figure out what's been
> going wrong.
> 
> There is a patch in the -mm series which causes leaks in both
> sock_inode_cache and dentry_cache for me during DVB playback (thanks
> to slabtop). 
> 
> 2.6.16 is fine (no leakage), 2.6.16-mm1 has this problem (~ 2MB/s in
> each cache).

Do you mean that the problem has been present in -mm kernels since the
2.6.14/15 timeframe, and not in mainline?

> I'm using dvbstream and sending the output to /dev/null,  dvb modules
> loaded are dvb_usb_vp7045, dvb_usb, dvb_core, dvb_pll.  It's an EHCI USB
> device running on a Dell D600 latitude.
> 
> turning on some debugging and looking at /proc/slab_allocators and
> /proc/page_owners shows that the most prevalent page owners are:
> 
> (5363 out of 5631)
> Page allocated via order 0, mask 0xd0
> [0xc0161079] poison_obj+41
> [0xc0162355] cache_alloc_refill+981
> [0xc0161889] cache_alloc_debugcheck_after+169
> [0xc01d5169] vsnprintf+857
> [0xc0247eec] lock_sock+204
> [0xc0244999] sock_alloc_inode+25
> [0xc0161f73] kmem_cache_alloc+131
> [0xc027a4b4] inet_csk_accept+436
> 
> (1989 out of 2734)
> Page allocated via order 0, mask 0xd0
> [0xc0162355] cache_alloc_refill+981
> [0xc0161079] poison_obj+41
> [0xc0161079] poison_obj+41
> [0xc01d5169] vsnprintf+857
> [0xc0182341] d_alloc+33
> [0xc0161f73] kmem_cache_alloc+131
> [0xc0182341] d_alloc+33
> [0xc02461e0] sock_attach_fd+96
> 

Strange.  Are you sure that they really leak?  Doing

	echo 3 > /proc/sys/vm/drop_caches

doesn't make them go away?