Re: [PATCH v17 2/3] mm: memory-failure: move return value documentation to function declaration

[jane.chu@oracle.com]

On 12/1/2024 7:05 PM, Shuai Xue wrote:
> Part of return value comments for memory_failure() were originally
> documented at the call site. Move those comments to the function
> declaration to improve code readability and to provide developers with
> immediate access to function usage and return information.
>
> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
> ---
>   arch/x86/kernel/cpu/mce/core.c |  7 -------
>   mm/memory-failure.c            | 10 +++++++---
>   2 files changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
> index 7fb5556a0b53..d1dd7f892514 100644
> --- a/arch/x86/kernel/cpu/mce/core.c
> +++ b/arch/x86/kernel/cpu/mce/core.c
> @@ -1398,13 +1398,6 @@ static void kill_me_maybe(struct callback_head *cb)
>   		return;
>   	}
>   
> -	/*
> -	 * -EHWPOISON from memory_failure() means that it already sent SIGBUS
> -	 * to the current process with the proper error info,
> -	 * -EOPNOTSUPP means hwpoison_filter() filtered the error event,
> -	 *
> -	 * In both cases, no further processing is required.
> -	 */
>   	if (ret == -EHWPOISON || ret == -EOPNOTSUPP)
>   		return;
>   
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index a7b8ccd29b6f..14c316d7d38d 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2211,9 +2211,13 @@ static void kill_procs_now(struct page *p, unsigned long pfn, int flags,
>    * Must run in process context (e.g. a work queue) with interrupts
>    * enabled and no spinlocks held.
>    *
> - * Return: 0 for successfully handled the memory error,
> - *         -EOPNOTSUPP for hwpoison_filter() filtered the error event,
> - *         < 0(except -EOPNOTSUPP) on failure.
> + * Return:
> + *   0             - success,
> + *   -ENXIO        - memory not managed by the kernel
> + *   -EOPNOTSUPP   - hwpoison_filter() filtered the error event,
> + *   -EHWPOISON    - the page was already poisoned, potentially
> + *                   kill process,
> + *   other negative values - failure.
>    */
>   int memory_failure(unsigned long pfn, int flags)
>   {

Looks good.

Reviewed-by: Jane Chu <jane.chu@oracle.com>

-jane