Re: [patch] slab: always follow arch requested alignments

[Pekka Enberg]

Hi Heiko,

On 7/22/06, Heiko Carstens <heiko.carstens@xxxxxxxxxx> wrote:
> Sorry, I should have mentioned it: on s390 (32 bit) we set
> #define ARCH_KMALLOC_MINALIGN 8.
> This is needed since our common I/O layer allocates data structures that need
> to have an eight byte alignment. Now, if I turn on DEBUG_SLAB, nothing works
> anymore, simply because the slab cache code ignores ARCH_KMALLOC_MINALIGN and
> uses an BYTES_PER_WORD alignment instead, which it shouldn't:

This is the bit I missed, sorry. I thought that the s390 hardware
mandates 8 byte alignment, but it really doesn't. So you're absolutely
right, you don't need to set ARCH_SLAB_MINALIGN and the alignment
calculation in slab is indeed broken for both, architecture and caller
mandated alignments.

                                    Pekka
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/