Message-ID: <4538F7B3.4020207@mvista.com>
Date: Fri, 20 Oct 2006 09:22:11 -0700
From: Kevin Hilman <khilman@mvista.com>
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To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] slab debug and ARCH_SLAB_MINALIGN don't get along
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Pekka Enberg wrote:

> On 10/19/06, Kevin Hilman <khilman@mvista.com> wrote:
>> When CONFIG_SLAB_DEBUG is used in combination with ARCH_SLAB_MINALIGN,
>> some debug flags should be disabled which depend on BYTES_PER_WORD
>> alignment.
>>
>> The disabling of these debug flags is not properly handled when
>> BYTES_PER_WORD < ARCH_SLAB_MEMALIGN < cache_line_size()
>>
>> This patch fixes that and also adds an alignment check to
>> cache_alloc_debugcheck_after() when ARCH_SLAB_MINALIGN is used.
> 
> You forgot to mention which case you are fixing in the patch
> description (that is, SLAB_HWCACHE_ALIGN, when cache_line_size() >
> BYTES_PER_WORD) which made the patch bit hard to decipher. Anyway,
> looks good, thanks!

Hi Pekka,

I found this on an ARM platform where ARCH_SLAB_MINALIGN=8, and the
default SLAB_HWCACHE_ALIGN is set also.

The ARM EABI requires 8-byte alignment to take full advantage of 8-byte
loads/stores for ARM arch >= v5.

Kevin
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