Messages in this thread |  | | | Date | Wed, 26 Jul 2006 12:52:04 +0200 | | From | Heiko Carstens <> | | Subject | Re: [patch 2/2] slab: always consider arch mandated alignment |
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On Wed, Jul 26, 2006 at 01:37:42PM +0300, Pekka J Enberg wrote: > On Wed, 26 Jul 2006, Heiko Carstens wrote: > > It's enough to fix the ARCH_SLAB_MINALIGN problem. But it does _not_ fix the > > ARCH_KMALLOC_MINALIGN problem. s390 currently only uses ARCH_KMALLOC_MINALIGN > > since that should be good enough and it doesn't disable as much debugging > > as ARCH_SLAB_MINALIGN does. > > What exactly isn't clear from the description of the first patch? Or why do > > you consider it bogus? > > Now I am confused. What do you mean by "doesn't disable as much debugging > as ARCH_SLAB_MINALIGN does"? AFAICT, the SLAB_RED_ZONE and SLAB_STORE_USER > options _require_ BYTES_PER_WORD alignment, so if s390 requires 8 > byte alignment, you can't have them debugging anyhow...
We only specify ARCH_KMALLOC_MINALIGN, since that aligns only the kmalloc caches, but it doesn't disable debugging on other caches that are created via kmem_cache_create() where an alignment of e.g. 0 is specified.
The point of the first patch is: why should the slab cache be allowed to chose an aligment that is less than what the caller specified? This does very likely break things. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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