Re: [PATCH 2/8] Function for reading the Aarch64 SVE vector length.

Pedro Alves
2018-05-31T14:55:57Z

On 05/11/2018 11:52 AM, Alan Hayward wrote:
> Add a method for reading the SVE vector length using ptrace. This returns
> 0 for systems without SVE support.
>
> Note the defines taken from Linux kernel headers in aarch64-sve-linux-ptrace.h.
> See the covering email for details about this.

Note that since the cover email doesn't make it to the git repo, it's better to
do things the other way around, leave the details in the commit, and a
summary in the cover letter. Someone looking at git log won't have a reference
to the cover letter. Or, if it makes sense for readers of the code, as
opposed to just a rationale for a change, put it in comments instead. (I don't
know whether that's true, just stating a principle.)

>
> There are multiple ways of expressing the vector length. Thankfully these are
> all wll defined. I've added convertors for going from one to the other.

"well", "converters".

> +struct user_sve_header {
> + __u32 size; /* total meaningful regset content in bytes */
> + __u32 max_size; /* maxmium possible size for this thread */

"maximum"

Thanks,
Pedro Alves