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    SubjectRe: [patch 2/2] slab: always consider arch mandated alignment
    On Wed, 26 Jul 2006, Manfred Spraul wrote:

    > > Thus the patch is correct, it's a bug in the slab allocator. If
    > > HWCACHE_ALIGN
    > > > is set, then the allocator ignores align or ARCH_SLAB_MINALIGN.
    > >
    > >
    > > But then Heiko does not want to set ARCH_SLAB_MINALIGN at all. This is not
    > > the issue we are discussing. In the DEBUG case he wants
    > > ARCH_KMALLOC_MINALIGN to be enforced even if ARCH_SLAB_MINALIGN is not set.
    > >
    > The kmalloc caches are allocated with HWCACHE_ALIGN+ARCH_KMALLOC_MINALIGN. The
    > logic in kmem_cache_create didn't handle that case correctly.
    > On most architectures, ARCH_KMALLOC_MINALIGN is 0. Thus SLAB_DEBUG redzones
    > everything.
    > On s390, ARCH_KMALLOC_MINALIGN is 8. This disables redzoning.
    >
    > Ok?

    So Redzoning etc will now be diabled regardless even if
    ARCH_SLAB_MINALIGN is not set but another alignment is given to
    kmem_cache_alloc?

    So we sacrifice the ability to worsen the performance of slabs by
    misaligning them for debugging purposes.
    -
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