Re: [RFC PATCH] memalloc_noio: update the comment to make it cleaner

[Xiubo Li]

On 2019/9/18 16:14, Michal Hocko wrote:
> On Wed 18-09-19 16:02:52, Xiubo Li wrote:
> > On 2019/9/18 15:25, Michal Hocko wrote:
> > > On Wed 18-09-19 04:58:20, xiubli@xxxxxxxxxx wrote:
> > > > From: Xiubo Li <xiubli@xxxxxxxxxx>
> > > >
> > > > The GFP_NOIO means all further allocations will implicitly drop
> > > > both __GFP_IO and __GFP_FS flags and so they are safe for both the
> > > > IO critical section and the the critical section from the allocation
> > > > recursion point of view. Not only the __GFP_IO, which a bit confusing
> > > > when reading the code or using the save/restore pair.
> > > Historically GFP_NOIO has always implied GFP_NOFS as well. I can imagine
> > > that this might come as an surprise for somebody not familiar with the
> > > code though.
> > Yeah, it true.
> >
> > >    I am wondering whether your update of the documentation
> > > would be better off at __GFP_FS, __GFP_IO resp. GFP_NOFS, GFP_NOIO level.
> > > This interface is simply a way to set a scoped NO{IO,FS} context.
> > The "Documentation/core-api/gfp_mask-from-fs-io.rst" is already very detail
> > about them all.
> >
> > This fixing just means to make sure that it won't surprise someone who is
> > having a quickly through some code and not familiar much about the detail.
> > It may make not much sense ?
> Ohh, I do not think this would be senseless. I just think that the NOIO
> implying NOFS as well should be described at the level where they are
> documented rather than the api you have chosen.

Hmm, yeah totally agree :-)

Thanks
BRs