On Fri, Sep 04, 2026 at 03:16:41PM -0400, Steven Rostedt wrote:
> From: Steven Rostedt <[email protected]>
> 
> Instead of hard coding 30 for the number of bits used for the static
> buffer ids in two places, create a macro. This way if it changes in the
> future, it will change in all the locations that use it.
> 
> Signed-off-by: Steven Rostedt <[email protected]>
> ---
>  kernel/trace/ring_buffer.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
> index 220b8405adfc..b88c75b52e8f 100644
> --- a/kernel/trace/ring_buffer.c
> +++ b/kernel/trace/ring_buffer.c
> @@ -335,6 +335,9 @@ static __always_inline unsigned int 
> rb_read_page_capacity(struct buffer_data_rea
>       return (PAGE_SIZE << rpage->order) - BUF_PAGE_HDR_SIZE;
>  }
>  
> +/* The number of bits for static buffer ids */
> +#define RB_STATIC_BITS       30
> +
>  /*
>   * Note, the buffer_page list must be first. The buffer pages
>   * are allocated in cache lines, which means that each buffer
> @@ -350,7 +353,7 @@ struct buffer_page {
>       local_t          entries;       /* entries on this page */
>       unsigned long    real_end;      /* real end of data */
>       unsigned         order;         /* order of the page */
> -     u32              id:30;         /* ID for external mapping */
> +     u32              id:RB_STATIC_BITS; /* ID for external mapping */
>       u32              range:1;       /* Mapped via a range */
>       struct buffer_data_page *page;  /* Actual data page */
>  };
> @@ -663,7 +666,7 @@ static unsigned long rb_static_max_pages(void)
>        * Static ring buffers are using bpage::id and must account for the
>        * reader page.
>        */
> -     return (1UL << 30) - 1;
> +     return (1UL << RB_STATIC_BITS) - 1;
>  }
>  
>  struct ring_buffer_iter {
> -- 
> 2.53.0
>

Reviewed-by: Vincent Donnefort <[email protected]>

-- 
Vincent

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