Re: [PATCH v2] doc: document scope NOFS, NOIO APIs

From: Michal Hocko
Date: Tue May 29 2018 - 08:37:15 EST


On Tue 29-05-18 05:51:58, Jonathan Corbet wrote:
> On Tue, 29 May 2018 10:26:44 +0200
> Michal Hocko <mhocko@xxxxxxxxxx> wrote:
>
> > Although the api is documented in the source code Ted has pointed out
> > that there is no mention in the core-api Documentation and there are
> > people looking there to find answers how to use a specific API.
>
> So, I still think that this:
>
> > +The traditional way to avoid this deadlock problem is to clear __GFP_FS
> > +respectively __GFP_IO (note the latter implies clearing the first as well) in
>
> doesn't read the way you intend it to. But we've sent you in more
> than enough circles on this already, so I went ahead and applied it;
> wording can always be tweaked later.

Thanks a lot Jonathan! I am open to any suggestions of course and can
follow up with some refinements. Just for the background. The above
paragraph is meant to say that:
- clearing __GFP_FS is a way to avoid reclaim recursion into filesystems
deadlocks
- clearing __GFP_IO is a way to avoid reclaim recursion into the IO
layer deadlocks
- GFP_NOIO implies __GFP_NOFS

> You added the kerneldoc comments, but didn't bring them into your new
> document. I'm going to tack this on afterward, hopefully nobody will
> object.

I have to confess I've never studied how the rst and kerneldoc should be
interlinked so thanks for the fix up!
--
Michal Hocko
SUSE Labs