Re: [PATCH v3 2/4] mm/ksm: add sysfs knobs for advisor

David Hildenbrand
2023-12-12T13:45:37Z

On 05.12.23 00:49, Stefan Roesch wrote:
> This adds four new knobs for the KSM advisor to influence its behaviour.
>
> The knobs are:
> - advisor_mode:
> none: no advisor (default)
> scan-time: scan time advisor
> - advisor_max_cpu: 70 (default, cpu usage percent)
> - advisor_min_pages: 500 (default)
> - advisor_max_pages: 30000 (default)
> - advisor_target_scan_time: 200 (default in seconds)
>
> The new values will take effect on the next scan round.
>
> Signed-off-by: Stefan Roesch <shr@devkernel.io>
> ---
> mm/ksm.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 127 insertions(+)
>
> diff --git a/mm/ksm.c b/mm/ksm.c
> index b27010fa2e946..18b7185bbc65b 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -3735,6 +3735,128 @@ static ssize_t smart_scan_store(struct kobject *kobj,
> }
> KSM_ATTR(smart_scan);
>
> +static ssize_t advisor_mode_show(struct kobject *kobj,
> + struct kobj_attribute *attr, char *buf)
> +{
> + const char *output;
> +
> + if (ksm_advisor == KSM_ADVISOR_NONE)
> + output = "[none] scan-time";
> + else if (ksm_advisor == KSM_ADVISOR_SCAN_TIME)
> + output = "none [scan-time]";
> +
> + return sysfs_emit(buf, "%s\n", output);
> +}
> +
> +static ssize_t advisor_mode_store(struct kobject *kobj,
> + struct kobj_attribute *attr, const char *buf,
> + size_t count)
> +{
> + if (sysfs_streq("scan-time", buf))
> + ksm_advisor = KSM_ADVISOR_SCAN_TIME;
> + else if (sysfs_streq("none", buf))
> + ksm_advisor = KSM_ADVISOR_NONE;
> + else
> + return -EINVAL;
> +
> + /* Set advisor default values */
> + init_advisor();

Is the "init_advisor()" really required?

> + set_advisor_defaults();

That function should go to this patch.

--
Cheers,

David / dhildenb