On Tue, 25 Jun 2024 14:26:05 +0100 Tvrtko Ursulin <tursulin@xxxxxxxxxx> wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxx>
>
> If a task has had MPOL_F_NUMA_BALANCING set it is useful to show that in
> procfs. Teach the mpol_to_str helper about its existance and while at it
> update the comment to account for "weighted interleave" when suggesting
> a recommended buffer size.
>
> ...
>
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -3293,8 +3293,9 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
> * @pol: pointer to mempolicy to be formatted
> *
> * Convert @pol into a string. If @buffer is too short, truncate the string.
> - * Recommend a @maxlen of at least 32 for the longest mode, "interleave", the
> - * longest flag, "relative", and to display at least a few node ids.
> + * Recommend a @maxlen of at least 42 for the longest mode, "weighted
> + * interleave", the longest flag, "balancing", and to display at least a few
> + * node ids.
> */
> void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
> {
> @@ -3331,12 +3332,15 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
> p += snprintf(p, buffer + maxlen - p, "=");
>
> /*
> - * Currently, the only defined flags are mutually exclusive
> + * The below two flags are mutually exclusive:
> */
> if (flags & MPOL_F_STATIC_NODES)
> p += snprintf(p, buffer + maxlen - p, "static");
> else if (flags & MPOL_F_RELATIVE_NODES)
> p += snprintf(p, buffer + maxlen - p, "relative");
> +
> + if (flags & MPOL_F_NUMA_BALANCING)
> + p += snprintf(p, buffer + maxlen - p, "balancing");
> }
>
> if (!nodes_empty(nodes))
Is it strange to report this via mount options? `static' and
`relative' can be set via mount options but afaict `balancing' cannot?
I guess not...
Documentation/filesystems/tmpfs.rst appears to be a suitable place to
document this new userspace API please.
