Re: [RFC PATCH v3] sparc64: Add support for Application Data Integrity (ADI)

From: Michal Hocko
Date: Fri Jan 06 2017 - 04:21:45 EST


On Thu 05-01-17 13:30:10, Khalid Aziz wrote:
[...]
> It is very tempting to restrict tags to PAGE_SIZE granularity since it makes
> code noticeably simpler and that is indeed going to be the majority of
> cases. Sooner or later somebody would want to use multiple tags per page
> though.

I didn't get to read the patch throughly yet but I am really confused by
this statement. The api is mprotect based which makes it ineherently
PAGE_SIZE granular. How do you want to achieve cache line granularity
with this API?

And I would really vote for simplicity first... Subpage granularity
sounds way too tricky...
--
Michal Hocko
SUSE Labs