[PATCH v3] Documentation/mm/page_owner.rst: delete frequently changing experimental data

From: Yixuan Cao
Date: Wed Oct 05 2022 - 07:52:00 EST

The kernel size changes due to many factors, such as compiler
version, configuration, and the build environment. This makes
size comparison figures irrelevant to reader's setup.

Remove these figures and describe the effects of page owner
to the kernel size in general instead.

Thanks for Jonathan Corbet, Bagas Sanjaya, Mike Rapoport and
Bagas Sanjaya's constructive suggestions.

Signed-off-by: Yixuan Cao <caoyixuan2019@xxxxxxxxxxxxxxxx>
Documentation/mm/page_owner.rst | 20 ++++----------------
1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/Documentation/mm/page_owner.rst b/Documentation/mm/page_owner.rst
index f18fd8907049..127514955a5e 100644
--- a/Documentation/mm/page_owner.rst
+++ b/Documentation/mm/page_owner.rst
@@ -38,22 +38,10 @@ not affect to allocation performance, especially if the static keys jump
label patching functionality is available. Following is the kernel's code
size change due to this facility.

-- Without page owner::
- text data bss dec hex filename
- 48392 2333 644 51369 c8a9 mm/page_alloc.o
-- With page owner::
- text data bss dec hex filename
- 48800 2445 644 51889 cab1 mm/page_alloc.o
- 6662 108 29 6799 1a8f mm/page_owner.o
- 1025 8 8 1041 411 mm/page_ext.o
-Although, roughly, 8 KB code is added in total, page_alloc.o increase by
-520 bytes and less than half of it is in hotpath. Building the kernel with
-page owner and turning it on if needed would be great option to debug
-kernel memory problem.
+Although enabling page owner increases kernel size by several kilobytes,
+most of this code is outside page allocator and its hot path. Building
+the kernel with page owner and turning it on if needed would be great
+option to debug kernel memory problem.

There is one notice that is caused by implementation detail. page owner
stores information into the memory from struct page extension. This memory