Re: [RESEND PATCH v4 13/15] fs/resctrl: Add interface to modify kernel-mode via info/kernel_mode

From: Reinette Chatre

Date: Thu Aug 13 2026 - 17:21:30 EST


Hi Babu,

On 8/13/26 1:55 PM, Babu Moger wrote:
> On 8/10/26 22:40, Reinette Chatre wrote:
>> On 7/7/26 2:50 PM, Babu Moger wrote:


>>> + *
>>> + * Return: @nbytes on success, negative errno with last_cmd_status set on error.
>>> + */
>>> +static ssize_t resctrl_kernel_mode_write(struct kernfs_open_file *of,
>>> +                     char *buf, size_t nbytes, loff_t off)
>>> +{
>>> +    enum resctrl_kernel_mode mode;
>>> +    char *mode_str, *group_str, *slash;
>>> +    const char *ctrl_name, *mon_name;
>>

...

>>> +
>>> +    for (mode = 0; mode < RESCTRL_NUM_KERNEL_MODES; mode++)
>>> +        if (!strcmp(mode_str, resctrl_mode_str[mode]))
>>> +            break;
>>> +
>>> +    if (mode == RESCTRL_NUM_KERNEL_MODES) {
>>> +        rdt_last_cmd_puts("Unknown kernel mode\n");
>>> +        ret = -EINVAL;
>>> +        goto out_unlock;
>>> +    }
>>> +
>>> +    if (!(test_bit(mode, &resctrl_kcfg.kmode))) {
>>> +        rdt_last_cmd_puts("Kernel mode not available\n");
>>> +        ret = -EINVAL;
>>> +        goto out_unlock;
>>> +    }
>>> +
>>> +    /*
>>> +     * INHERIT mode binds no rdtgroup. Ignore any user-supplied :group=
>>> +     * suffix and let show print the mode without a group.
>>
>> copy&paste?
>
> Hmm.. Text seems correct here to me. Did I miss something?

This is the function that parses user input so the comment describing what should
be displayed to user space seems out of place.

Reinette