Re: [BUG] ibm_emac: kernel panic with CONFIG_SLOB=y

On Tue, Aug 01, 2006 at 10:40:11PM +0200, Karol Lewandowski wrote:

Hi,

I'm getting reproductible kernel panic when I use smaller SLOB
allocator (instead of SLAB).  This is reproductible but very randomly
-- sometimes it happens during bootup, sometimes few minutes later.

Hardware is custom board with IBM405EP (very close to Bubingna, just
no RTC):

# cat /proc/cpuinfo
processor	: 0
cpu		: 405EP
clock		: 200MHz
revision	: 9.80 (pvr 5121 0950)
bogomips	: 199.47
machine		: MagicBox
plb bus clock	: 100MHz
pci bus clock	: 25MHz

Enabling SLAB instead of SLOB fixes this, so I assume this is driver
issue.

This is probably the same issue  I had with SLAB debugging.

In short, those allocators aren't compatible with non-coherent cache 
archs (like 4xx), because driver assumes at least L1 cache line 
alignment for all allocated memory.

For more info, you can read this post:

http://ozlabs.org/pipermail/linuxppc-embedded/2006-February/022087.html

-- 
Eugene