Re: [PATCH v3 2/2] mm: shmem: refactor thpsize_shmem_enabled_show() with helper arrays

[Lorenzo Stoakes <ljs@kernel.org>]

On Mon, May 18, 2026 at 12:32:38PM +0000, ranxiaokai627@163.com wrote:
> From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>
> Replace the hardcoded if/else chain of test_bit() calls and string
> literals in thpsize_shmem_enabled_show() with a loop over
> huge_shmem_orders_by_mode[] and huge_shmem_enabled_mode_strings[] arrays.
>
> This makes thpsize_shmem_enabled_show() consistent with
> thpsize_shmem_enabled_store() and eliminates duplicated mode name strings.
>
> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>

From: ranxiaokai627@163.com

This does not match the From: field of the email.

This is violating kernel process. See
https://docs.kernel.org/process/submitting-patches.html

Please either update this to your 163 email account or resend from your
zte.com.cn address, otherwise we can't take this.

Cheers, Lorenzo

> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Reviewed-by: Breno Leitao <leitao@debian.org>
> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
> ---
>  mm/shmem.c | 36 +++++++++++++++++++++++-------------
>  1 file changed, 23 insertions(+), 13 deletions(-)
>
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 46d2cfc30823..197c9cc314c5 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -5553,20 +5553,30 @@ static ssize_t thpsize_shmem_enabled_show(struct kobject *kobj,
>  					  struct kobj_attribute *attr, char *buf)
>  {
>  	int order = to_thpsize(kobj)->order;
> -	const char *output;
> -
> -	if (test_bit(order, &huge_shmem_orders_always))
> -		output = "[always] inherit within_size advise never";
> -	else if (test_bit(order, &huge_shmem_orders_inherit))
> -		output = "always [inherit] within_size advise never";
> -	else if (test_bit(order, &huge_shmem_orders_within_size))
> -		output = "always inherit [within_size] advise never";
> -	else if (test_bit(order, &huge_shmem_orders_madvise))
> -		output = "always inherit within_size [advise] never";
> -	else
> -		output = "always inherit within_size advise [never]";
> +	int active = HUGE_SHMEM_ENABLED_NEVER;
> +	int len = 0;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(huge_shmem_orders_by_mode); i++) {
> +		if (test_bit(order, huge_shmem_orders_by_mode[i])) {
> +			active = i;
> +			break;
> +		}
> +	}
> +
> +	for (i = 0; i < ARRAY_SIZE(huge_shmem_enabled_mode_strings); i++) {
> +		if (i == active)
> +			len += sysfs_emit_at(buf, len, "[%s] ",
> +					     huge_shmem_enabled_mode_strings[i]);
> +		else
> +			len += sysfs_emit_at(buf, len, "%s ",
> +					     huge_shmem_enabled_mode_strings[i]);
> +	}
> +
> +	/* Replace trailing space with newline */
> +	buf[len - 1] = '\n';
>
> -	return sysfs_emit(buf, "%s\n", output);
> +	return len;
>  }
>
>  static bool set_shmem_enabled_mode(int order, enum huge_shmem_enabled_mode mode)
> --
> 2.25.1
>
>