Re: [PATCH v16 07/11] secretmem: use PMD-size pages to amortize direct map fragmentation

Michal Hocko
2021-01-29T07:54:15Z

On Thu 28-01-21 13:05:02, James Bottomley wrote:
> On Thu, 2021-01-28 at 14:01 +0100, Michal Hocko wrote:
[...]
> > I am also still not sure why this whole thing is not just a
> > ramdisk/ramfs which happens to unmap its pages from the direct
> > map. Wouldn't that be a much more easier model to work with? You
> > would get an access control for free as well.
>
> The original API was a memfd which does have this access control as
> well. However, the decision was made after much discussion to go with
> a new system call instead.

It would be really great to summarize reasoning behind that decision.
Not only for those who were not part of those discussion but also for
anybody who will be reading git log and want to try to understand that
reasoning. Go and read 15 versions of patchset to find that out is
certainly not great use of time.

Thanks!
--
Michal Hocko
SUSE Labs