Re: [PATCH v6 07/36] nds32: Exception handling

From: Vincent Chen
Date: Tue Jan 30 2018 - 05:02:24 EST


2018-01-24 19:10 GMT+08:00 Arnd Bergmann <arnd@xxxxxxxx>:
> On Wed, Jan 24, 2018 at 12:09 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>> On Wed, Jan 24, 2018 at 11:53 AM, Vincent Chen <deanbo422@xxxxxxxxx> wrote:
>>> 2018-01-18 18:14 GMT+08:00 Arnd Bergmann <arnd@xxxxxxxx>:
>
>> Ok. I still wonder about the kernel part of this though: is it a good idea
>> for user space to configure whether the kernel does unaligned
>> accesses? I would think that the kernel should just be fixed in such
>> a case.
>
> To clarify: I'm asking only about unaligned accesses from kernel code itself,
> which is generally considered a bug when
> CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is disabled.
>
> Arnd

Thanks for your comments.

For performance, we decide always disable
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS even if hardware supports
unaligned accessing. Therefore, I will remove kernel unaligned accessing from
nds32/mm/alignment.c. In other words, alignment.c only addresses unaligned
accessing for user space.

Vincent