[PATCH] ring-buffer: Remove unused function __rb_data_page_index()

[PATCH] ring-buffer: Remove unused function __rb_data_page_index()

[Matthias Kaehlcke]

This fixes the following warning when building with clang:

kernel/trace/ring_buffer.c:1842:1: error: unused function
    '__rb_data_page_index' [-Werror,-Wunused-function]

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
 kernel/trace/ring_buffer.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 4ae268e687fe..a6b87582c4ff 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1800,12 +1800,6 @@ void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
 }
 EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite);
 
-static __always_inline void *
-__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
-{
-	return bpage->data + index;
-}
-
 static __always_inline void *__rb_page_index(struct buffer_page *bpage, unsigned index)
 {
 	return bpage->page->data + index;
-- 
2.13.0.303.g4ebf302169-goog

Re: [PATCH] ring-buffer: Remove unused function __rb_data_page_index()

[Doug Anderson]

Hi,

This appears to have been introduced in 2009 by commit afbab76a62b6
("ring-buffer: have read page swap increment counter with page
entries"), which removed the user of the function but not the function
itself.  If folks were so inclined, this could be picked back to
linux-stable, but I'm not sure it's worth it.

On Wed, May 17, 2017 at 5:14 PM, Matthias Kaehlcke <mka@chromium.org> wrote:
> This fixes the following warning when building with clang:
>
> kernel/trace/ring_buffer.c:1842:1: error: unused function
>     '__rb_data_page_index' [-Werror,-Wunused-function]
>
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
>  kernel/trace/ring_buffer.c | 6 ------
>  1 file changed, 6 deletions(-)
>
> diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
> index 4ae268e687fe..a6b87582c4ff 100644
> --- a/kernel/trace/ring_buffer.c
> +++ b/kernel/trace/ring_buffer.c
> @@ -1800,12 +1800,6 @@ void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
>  }
>  EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite);
>
> -static __always_inline void *
> -__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
> -{
> -       return bpage->data + index;
> -}
> -
>  static __always_inline void *__rb_page_index(struct buffer_page *bpage, unsigned index)
>  {
>         return bpage->page->data + index;

FWIW:

Reviewed-by: Douglas Anderson <dianders@chromium.org>

Re: [PATCH] ring-buffer: Remove unused function __rb_data_page_index()

[Steven Rostedt]

On Thu, 18 May 2017 12:40:02 -0700
Doug Anderson <dianders@chromium.org> wrote:

> Hi,
> 
> This appears to have been introduced in 2009 by commit afbab76a62b6
> ("ring-buffer: have read page swap increment counter with page
> entries"), which removed the user of the function but not the function
> itself.  If folks were so inclined, this could be picked back to
> linux-stable, but I'm not sure it's worth it.

It doesn't do anything but waste some disk space in the source
repository. It's a static inline function, which means it's not created
unless something calls it.

Thus, not worth the stable churn.

-- Steve

Re: [PATCH] ring-buffer: Remove unused function __rb_data_page_index()

[Doug Anderson]

Hi,

On Thu, May 18, 2017 at 12:46 PM, Steven Rostedt <rostedt@goodmis.org> wrote:
> On Thu, 18 May 2017 12:40:02 -0700
> Doug Anderson <dianders@chromium.org> wrote:
>
>> Hi,
>>
>> This appears to have been introduced in 2009 by commit afbab76a62b6
>> ("ring-buffer: have read page swap increment counter with page
>> entries"), which removed the user of the function but not the function
>> itself.  If folks were so inclined, this could be picked back to
>> linux-stable, but I'm not sure it's worth it.
>
> It doesn't do anything but waste some disk space in the source
> repository. It's a static inline function, which means it's not created
> unless something calls it.
>
> Thus, not worth the stable churn.

Yup, that's sane.  I guess not much chance of someone trying to get
clang to run w/ no warnings by just picking stable patches.  ;-)

-Doug

Re: [PATCH] ring-buffer: Remove unused function __rb_data_page_index()

[Steven Rostedt]

On Wed, 17 May 2017 17:14:15 -0700
Matthias Kaehlcke <mka@chromium.org> wrote:

> This fixes the following warning when building with clang:
> 
> kernel/trace/ring_buffer.c:1842:1: error: unused function
>     '__rb_data_page_index' [-Werror,-Wunused-function]

Ug, I this patch somehow fell through. I'm applying it now.

-- Steve

> 
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
>  kernel/trace/ring_buffer.c | 6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
> index 4ae268e687fe..a6b87582c4ff 100644
> --- a/kernel/trace/ring_buffer.c
> +++ b/kernel/trace/ring_buffer.c
> @@ -1800,12 +1800,6 @@ void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
>  }
>  EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite);
>  
> -static __always_inline void *
> -__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
> -{
> -	return bpage->data + index;
> -}
> -
>  static __always_inline void *__rb_page_index(struct buffer_page *bpage, unsigned index)
>  {
>  	return bpage->page->data + index;