Re: [PATCH] fs/drop_caches: move drop_caches sysctls into its own file

From: Luis Chamberlain
Date: Tue Mar 21 2023 - 14:10:40 EST


On Tue, Mar 21, 2023 at 05:19:18PM +0000, Matthew Wilcox wrote:
> On Tue, Mar 21, 2023 at 09:56:03AM -0700, Luis Chamberlain wrote:
> > On Tue, Mar 21, 2023 at 04:42:32PM +0000, Matthew Wilcox wrote:
> > > On Tue, Mar 21, 2023 at 09:09:07PM +0800, Yangtao Li wrote:
> > > > +static struct ctl_table drop_caches_table[] = {
> > > > + {
> > > > + .procname = "drop_caches",
> > > > + .data = &sysctl_drop_caches,
> > > > + .maxlen = sizeof(int),
> > > > + .mode = 0200,
> > > > + .proc_handler = drop_caches_sysctl_handler,
> > > > + .extra1 = SYSCTL_ONE,
> > > > + .extra2 = SYSCTL_FOUR,
> > > > + },
> > > > + {}
> > > > +};
> > >
> > > Could we avoid doing this until we no longer need an entire zero entry
> > > after the last one?
> >
> > That may be 2-3 kernel release from now. The way to use ARRAY_SIZE()
> > really is to deprecate the crap APIs that allow messy directory sysctl
> > structures.
>
> I'm OK with waiting another year to commence this cleanup. We've lived
> with the giant tables for decades already. Better to get the new API
> right than split the tables now, then have to touch all the places
> again.

We can do that sure.

Luis