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

Jiaqi Yan
2024-07-02T04:15:18Z

On Mon, Jul 1, 2024 at 8:15 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Mon, 1 Jul 2024 18:49:12 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> > Hi all,
> >
> > After merging the mm tree, today's linux-next build (htmldocs) produced
> > these warnings:
> >
> > Documentation/admin-guide/sysctl/vm.rst:278: ERROR: Unexpected indentation.
> > Documentation/admin-guide/sysctl/vm.rst:279: WARNING: Block quote ends without a blank line; unexpected unindent.
> >
> > Introduced by commit
> >
> > 2cba7831f62c ("docs: mm: add enable_soft_offline sysctl")
>
> Well that's annoying.
>
> @@ -267,6 +268,37 @@ used::
> These are informational only. They do not mean that anything is wrong
> with your system. To disable them, echo 4 (bit 2) into drop_caches.
>
> +enable_soft_offline
> +===================
> +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.
> +- 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.
> +- 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
> + pages without compensation, reducing the capacity of the HugeTLB pool by 1.
> +
> + ...
>
> 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:

diff --git a/Documentation/admin-guide/sysctl/vm.rst
b/Documentation/admin-guide/sysctl/vm.rst
index 75e22137d849..74b4c0f65213 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.
+
- 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.
+
- 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

But I am having trouble testing the build, so wasn't able to validate
the change above:

Documentation$ make
/tools/net/ynl/ynl-gen-rst.py -o
/Documentation/networking/netlink_spec/index.rst -x
make: /tools/net/ynl/ynl-gen-rst.py: No such file or directory
make: *** [Makefile:113:
/Documentation/networking/netlink_spec/index.rst] Error 127

[1] https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#bullet-lists