Subject: Re: [patch 08/20] ibmveth: Dont overallocate buffers

From: Brian King <[email-masked]>
Date: Wed, 25 Aug 2010 08:44:16 -0500

On 08/23/2010 03:49 PM, Robert Jennings wrote:
> * Anton Blanchard ([email-masked]) wrote:
>> We were allocating a page, even though we always want 4k. Use kmalloc
>> instead of get_zeroed_page.
> 
> I get a failure during device open when we have a 4k allocation rather
> than a 64k page allocation.  This is running on a Power6 LPAR without
> AMS.
> 
> (drivers/net/ibmveth.c:621 ua:3000000c) ERROR: h_register_logical_lan failed with -4
> (drivers/net/ibmveth.c:626 ua:3000000c) ERROR: buffer TCE:0x300 filter TCE:0x2300 rxq desc:0x8000601000004000 MAC:0x763cbdd9d30c

According to the architecture, these buffers need to be 4k aligned buffers,
which is probably the cause of this failure.

-Brian

-- 
Brian King
Linux on Power Virtualization
IBM Linux Technology Center