Re: [PATCH v3] ad7877: keep dma rx buffers in seperate cache lines

[Pekka Enberg]

Hi Dmitry,

On Tue, May 11, 2010 at 9:33 AM, Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
>> what guarantee exactly do you have for that statement ?
>
> The data is kmalloced, kmalloc aligns on cacheline boundary AFAIK which
> means that next kmalloc data chunk will not share "our" cacheline.

No, there are no such guarantees. kmalloc() aligns on
ARCH_KMALLOC_MINALIGN or ARCH_SLAB_MINALIGN depending on which is
bigger but beyond that, there are no guarantees. You can, of course,
use kmem_cache_create() with SLAB_HWCACHE_ALIGN to align on cacheline
boundary.

                        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/