Re: Sysfs one-value-per-file (was Re: [PATCH] vmstat: don't auto expand the sysfs files)

[Pasha Tatashin]

On Wed, Dec 27, 2023 at 1:42 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, 26 Dec 2023 16:53:31 -0800 (PST) David Rientjes <rientjes@xxxxxxxxxx> wrote:
>
> > But for existing files and conventions, I think we should settle it as
> > "keep doing what you've been doing for 13+ years" and don't force this
> > argument every time a kernel developer wants to just add one more stat.
>
> Absolutely.  Let's do what makes most sense.  For new things, one value
> per file.  For stats which logically group with other existing stats,
> do whatever the existing other stats are currently doing.

The intent of "[PATCH] vmstat: don't auto expand the sysfs files" is
to do exactly this: keep the current fields in
/sys/devices/system/node/node*/vmstat as-is, but prevent future fields
added to node_stat, numa_stat, zone_stat from showing in vmstat.

Potentially, we could also extend checkpatch.pl to warn when
VMSTAT_SHOW_SYSFS is used in the future patches.

Pasha