Re: block: DMA alignment of IO buffer allocated from slab

[Andrey Ryabinin]

On 09/24/2018 06:58 PM, Bart Van Assche wrote:
> On Mon, 2018-09-24 at 18:52 +0300, Andrey Ryabinin wrote:
>> Yes, with CONFIG_DEBUG_SLAB=y, CONFIG_SLUB_DEBUG_ON=y kmalloc() guarantees
>> that result is aligned on ARCH_KMALLOC_MINALIGN boundary.
> 
> Had you noticed that Vitaly Kuznetsov showed that this is not the case? See
> also https://lore.kernel.org/lkml/87h8ij0zot.fsf@xxxxxxxxxxxxxxxxxxxx/.
> 

I'm not following. On x86-64 ARCH_KMALLOC_MINALIGN is 8, all pointers that Vitaly Kuznetsov showed are 8-byte aligned.

> Thanks,
> 
> Bart.
>