Re: linux-next: build warnings after merge of the mm tree

Jiaqi Yan
2024-07-02T23:55:20Z

On Tue, Jul 2, 2024 at 4:10 PM SeongJae Park <sj@kernel.org> wrote:
>
> Hello Jiaqi,
>
>
> On Mon, 1 Jul 2024 23:37:55 -0700 Jiaqi Yan <jiaqiyan@google.com> wrote:
>
> > On Mon, Jul 1, 2024 at 11:18 PM Andrew Morton <akpm@linux-foundation.org> wrote:
> > >
> > > On Mon, 1 Jul 2024 21:33:20 -0700 Jiaqi Yan <jiaqiyan@google.com> wrote:
> > >
> > > > > > This seems a reasonable thing to do so there's probably some way in
> > > > > > which to do it, but a bit of grepping failed to turn up examples in
> > > > > > existing .rst files. Can someone please suggest?
> > > > >
> > > > > It seems I need to add some blank lines according to [1], especially
> > > > > to add a blank line above the first list item:
>
> According to my understanding and testing on my machine, it seems we need blank
> lines only before and after the blocks.

Yes, as stated in [1], "The blank line above the first list item is
required; blank lines between list items (such as below this
paragraph) are optional."

>
> [...]
> >
> > Ah, sorry Andrew, I should sent out this diff, as there are more blank
> > lines needed:
> >
> > diff --git a/Documentation/admin-guide/sysctl/vm.rst
> > b/Documentation/admin-guide/sysctl/vm.rst
> > index 75e22137d849..f48eaa98d22d 100644
> > --- a/Documentation/admin-guide/sysctl/vm.rst
> > +++ b/Documentation/admin-guide/sysctl/vm.rst
> > @@ -274,12 +274,15 @@ Correctable memory errors are very common on
> > servers. Soft-offline is kernel's
> > solution for memory pages having (excessive) corrected memory errors.
> >
> > For different types of page, soft-offline has different behaviors / costs.
> > +
>
> So, this was needed to make 'make htmldocs' quiet on my machine.

Absolutely.

>
> > - For a raw error page, soft-offline migrates the in-use page's content to
> > a new raw page.
> > +
> > - For a page that is part of a transparent hugepage, soft-offline splits the
> > transparent hugepage into raw pages, then migrates only the raw error page.
> > As a result, user is transparently backed by 1 less hugepage, impacting
> > memory access performance.
> > +
>
> But above two blank lines were not really needed to make 'make htmldocs' calm,
> at least on my setup. Many other documents also don't have this kind of blank
> line.

Yes, they are optional.

>
> > - For a page that is part of a HugeTLB hugepage, soft-offline first migrates
> > the entire HugeTLB hugepage, during which a free hugepage will be consumed
> > as migration target. Then the original hugepage is dissolved into raw
> > @@ -296,8 +299,11 @@ the request to soft offline the pages. Its
> > default value is 1.
> >
> > It is worth mentioning that after setting enable_soft_offline to 0, the
> > following requests to soft offline pages will not be performed:
> > +
>
> Interestingly, 'make htmldocs' didn't complain even if I don't put this blank

In fact, without this blank line, even though make htmldocs doesn't
throw ERROR or WARNING, the output html file is broken: there is no
bullet point for the list items below.

> line. But for consistency (see the beginning of sysctl/vm.rst), I think having
> this would be good.

Agreed.

>
> > - Request to soft offline pages from RAS Correctable Errors Collector.
> > +
> > - On ARM, the request to soft offline pages from GHES driver.
> > +
>
> Again, same to the reason above, it seems above two blank lines are not really
> needed.

Yep, optional again. I mainly just want to be consistent.

>
> > - On PARISC, the request to soft offline pages from Page Deallocation Table.
> >
> > extfrag_threshold
> >
>
> I have no strong opinion about these, though. Having four more blank lines
> that might unnecessary is obviously no problem.
>
>
> Thanks,
> SJ