Re: Finding kernel RAM consumers ?

[Arnd Bergmann <arnd@arndb.de>]

On Tue, Jun 7, 2022 at 11:44 AM Russell King (Oracle)
<linux@armlinux.org.uk> wrote:
> On Tue, Jun 07, 2022 at 10:38:54AM +0200, Arnd Bergmann wrote:
> >
> > Yes, of course, and there is nothing wrong with that. We already see
> > Cortex-A7 cores down to 7nm, all running Linux, and I expect there
> > will likely be another 5 to 10 years of new 32-bit chips, and then another
> > 10 years of people putting the existing chips into production, and after
> > that a slow decline of users updating their kernels before supporting
> > 32-bit hardware becomes too expensive to support in the kernel.
>
> It should be noted that 20 years puts us past the 2038 32-bit time_t
> wrap problem - and although there's been work to address that in the
> UAPI, that doesn't mean that userspace will cope.
>
> Anyone deploying a system that is expected to still be live beyond
> the end of 32-bit time_t had better be testing their userspace for
> that event now!

That is absolutely true, but it's also independent of what kernel is
being used. I assume that anyone who is this memory constrained
is using 32-bit thumb userspace even on 64-bit kernels.

The base distro support in embedded systems using openembedded
with musl-1.2.x usually works fine beyond y2038, but of course each
system should be tested for this before shipping as there are still
bugs in less common code.

         arnd