Re: [PATCH] ipc: Limit sysctl value to IPCMNI

[Andrew Morton]

On Mon, 18 Jun 2018 13:27:24 +0800 Waiman Long <longman@xxxxxxxxxx> wrote:

> >>
> >> Maybe another possible solution would be to add another proc entry to
> >> handle this correctly, and make the old one only for compatibility.
> > Yes, I guess so.  Just leave the old tunable alone.  Possibly we
> > could add a printk_once("please switch to the new interface").
> 
> A problem with that is the fact that those sysctl parameters have been
> there for so long that it may be hard to persuade users to use the new
> sysctl parameters.

That's what a once-off warning could help with.  Tell them they're
using a deprecated interface.  It would take a few years, but when
people see the old interface is scheduled for removal, they'll switch,
over time.