Subject: Re: crash in kmem_cache_init

From: Pekka Enberg <[email-masked]>
Date: Wed, 23 Jan 2008 00:59:44 +0200

Hi,

Mel Gorman wrote:
> Faulting instruction address: 0xc0000000003c8c00
> cpu 0x0: Vector: 300 (Data Access) at [c0000000005c3840]
>     pc: c0000000003c8c00: __lock_text_start+0x20/0x88
>     lr: c0000000000dadec: .cache_grow+0x7c/0x338
>     sp: c0000000005c3ac0
>    msr: 8000000000009032
>    dar: 40
>  dsisr: 40000000
>   current = 0xc000000000500f10
>   paca    = 0xc000000000501b80
>     pid   = 0, comm = swapper
> enter ? for help
> [c0000000005c3b40] c0000000000dadec .cache_grow+0x7c/0x338
> [c0000000005c3c00] c0000000000db54c .fallback_alloc+0x1c0/0x224
> [c0000000005c3cb0] c0000000000db958 .kmem_cache_alloc+0xe0/0x14c
> [c0000000005c3d50] c0000000000dcccc .kmem_cache_create+0x230/0x4cc
> [c0000000005c3e30] c0000000004c05f4 .kmem_cache_init+0x310/0x640
> [c0000000005c3ee0] c00000000049f8d8 .start_kernel+0x304/0x3fc
> [c0000000005c3f90] c000000000008594 .start_here_common+0x54/0xc0
> 0:mon>

I mentioned this already but received no response (maybe I am missing 
something totally obvious here):

When we call fallback_alloc() because the current node has ->nodelists 
set to NULL, we end up calling kmem_getpages() with -1 as the node id 
which is then translated to numa_node_id() by alloc_pages_node. But the 
reason we called fallback_alloc() in the first place is because 
numa_node_id() doesn't have a ->nodelist which makes cache_grow() oops.

			Pekka