[PATCH] Documentation/mm/page_owner.rst: update experimental data

[PATCH] Documentation/mm/page_owner.rst: update experimental data

[Yixuan Cao]

I noticed some experimental data need to be updated.

Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
---
 Documentation/mm/page_owner.rst | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Documentation/mm/page_owner.rst b/Documentation/mm/page_owner.rst
index f18fd8907049..8e2545bb4e17 100644
--- a/Documentation/mm/page_owner.rst
+++ b/Documentation/mm/page_owner.rst
@@ -41,17 +41,17 @@ size change due to this facility.
 - Without page owner::
 
    text    data     bss     dec     hex filename
-   48392   2333     644   51369    c8a9 mm/page_alloc.o
+   58581   3166     652   62399    f3bf 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
+   59085   3294     652   63031    f637 mm/page_alloc.o
+   7464     125      28    7617    1dc1 mm/page_owner.o
+   1396      32       8    1436     59c 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
+Although, roughly, 9 KB code is added in total, page_alloc.o increase by
+632 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.
 
-- 
2.17.1

Re: [PATCH] Documentation/mm/page_owner.rst: update experimental data

[Jonathan Corbet]

Yixuan Cao <caoyixuan2019@email.szu.edu.cn> writes:

> I noticed some experimental data need to be updated.
>
> Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
> ---
>  Documentation/mm/page_owner.rst | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/mm/page_owner.rst b/Documentation/mm/page_owner.rst
> index f18fd8907049..8e2545bb4e17 100644
> --- a/Documentation/mm/page_owner.rst
> +++ b/Documentation/mm/page_owner.rst
> @@ -41,17 +41,17 @@ size change due to this facility.
>  - Without page owner::
>  
>     text    data     bss     dec     hex filename
> -   48392   2333     644   51369    c8a9 mm/page_alloc.o
> +   58581   3166     652   62399    f3bf 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
> +   59085   3294     652   63031    f637 mm/page_alloc.o
> +   7464     125      28    7617    1dc1 mm/page_owner.o
> +   1396      32       8    1436     59c 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
> +Although, roughly, 9 KB code is added in total, page_alloc.o increase by
> +632 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.

This seems like a fine patch...but I do have to wonder if it really
makes sense to maintain this information, which will surely be subject
to frequent change.  Perhaps the whole thing is better replaced with a
line saying that enabling page owner adds ~9KB?

Thanks,

jon

Re: [PATCH] Documentation/mm/page_owner.rst: update experimental data

[Bagas Sanjaya]

[-- Attachment #1: Type: text/plain, Size: 1732 bytes --]

On Thu, Aug 25, 2022 at 12:09:35PM -0600, Jonathan Corbet wrote:
> >  - Without page owner::
> >  
> >     text    data     bss     dec     hex filename
> > -   48392   2333     644   51369    c8a9 mm/page_alloc.o
> > +   58581   3166     652   62399    f3bf 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
> > +   59085   3294     652   63031    f637 mm/page_alloc.o
> > +   7464     125      28    7617    1dc1 mm/page_owner.o
> > +   1396      32       8    1436     59c 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
> > +Although, roughly, 9 KB code is added in total, page_alloc.o increase by
> > +632 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.
> 
> This seems like a fine patch...but I do have to wonder if it really
> makes sense to maintain this information, which will surely be subject
> to frequent change.  Perhaps the whole thing is better replaced with a
> line saying that enabling page owner adds ~9KB?
> 

The size figure above is from size(1) from binutils, for which the
command is run (maybe) against vmlinux.

So I would like to say "Enabling page owner increases vmlinux size by
several kilobytes."

Thanks.

-- 
An old man doll... just what I always wanted! - Clara

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH] Documentation/mm/page_owner.rst: update experimental data

[Mike Rapoport]

On Fri, Aug 26, 2022 at 09:30:46AM +0700, Bagas Sanjaya wrote:
> On Thu, Aug 25, 2022 at 12:09:35PM -0600, Jonathan Corbet wrote:
> > >  - Without page owner::
> > >  
> > >     text    data     bss     dec     hex filename
> > > -   48392   2333     644   51369    c8a9 mm/page_alloc.o
> > > +   58581   3166     652   62399    f3bf 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
> > > +   59085   3294     652   63031    f637 mm/page_alloc.o
> > > +   7464     125      28    7617    1dc1 mm/page_owner.o
> > > +   1396      32       8    1436     59c 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
> > > +Although, roughly, 9 KB code is added in total, page_alloc.o increase by
> > > +632 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.
> > 
> > This seems like a fine patch...but I do have to wonder if it really
> > makes sense to maintain this information, which will surely be subject
> > to frequent change.  Perhaps the whole thing is better replaced with a
> > line saying that enabling page owner adds ~9KB?
> > 
> 
> The size figure above is from size(1) from binutils, for which the
> command is run (maybe) against vmlinux.
> 
> So I would like to say "Enabling page owner increases vmlinux size by
> several kilobytes."

Looks like original text tried to emphasize that there is no significant
change to page allocator code, and I think it's worth keeping it. E.g.
leaving something like

"Although, enabling page owner increases kernel size by several kilobytes,
most of this code is outside page allocator and its hot path."
 
instead of size(1) output and the sentences before and after it.

> Thanks.
> 
> -- 
> An old man doll... just what I always wanted! - Clara



-- 
Sincerely yours,
Mike.

[PATCH v2] Documentation/mm/page_owner.rst: delete frequently changing experimental data

[Yixuan Cao]

Thanks for Jonathan Corbet, Bagas Sanjaya and Mike Rapoport's
constructive suggestions. Notice that the size(1) output is
changing frequently, I remove the two tables and describe them
in a general way. Doing so avoids having to repeatedly maintain
the two tables due to kernel changes.

Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
---
 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..1b661ad85647 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
-- 
2.17.1

Re: [PATCH v2] Documentation/mm/page_owner.rst: delete frequently changing experimental data

[Bagas Sanjaya]

On 10/5/22 16:10, Yixuan Cao wrote:
> Thanks for Jonathan Corbet, Bagas Sanjaya and Mike Rapoport's
> constructive suggestions. Notice that the size(1) output is
> changing frequently, I remove the two tables and describe them
> in a general way. Doing so avoids having to repeatedly maintain
> the two tables due to kernel changes.
> 

For the patch description, better write:

"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."

> Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
> ---
>  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..1b661ad85647 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.
>  

s/Although,/Although/

Thanks for reviewing.

-- 
An old man doll... just what I always wanted! - Clara

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

[Yixuan Cao]

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@email.szu.edu.cn>
---
 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
-- 
2.17.1

[PATCH v4] Documentation/mm/page_owner.rst: delete frequently changing experimental data

[Yixuan Cao]

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 and Mike Rapoport's
constructive suggestions.

Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
---
 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
-- 
2.17.1

Re: [PATCH v4] Documentation/mm/page_owner.rst: delete frequently changing experimental data

[Bagas Sanjaya]

On 10/5/22 21:55, Yixuan Cao wrote:
> 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 and Mike Rapoport's
> constructive suggestions.
> 

The credits paragraph above can be removed (should be between
dash line and diffstat).

Otherwise LGTM.

Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>

-- 
An old man doll... just what I always wanted! - Clara

[PATCH v5] Documentation/mm/page_owner.rst: delete frequently changing experimental data

[Yixuan Cao]

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.

Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
---
 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
-- 
2.17.1

Re: [PATCH v4] Documentation/mm/page_owner.rst: delete frequently changing experimental data

[Jonathan Corbet]

Yixuan Cao <caoyixuan2019@email.szu.edu.cn> writes:

> 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 and Mike Rapoport's
> constructive suggestions.
>
> Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
> ---
>  Documentation/mm/page_owner.rst | 20 ++++----------------
>  1 file changed, 4 insertions(+), 16 deletions(-)

Applied, thanks.

jon