Re: [PATCH] Increase default MLOCK_LIMIT to 8 MiB

Drew DeVault
2021-11-17T08:23:17Z

On Tue Nov 16, 2021 at 10:37 PM CET, Andrew Morton wrote:
> We're never going to get this right, are we? The only person who can
> decide on a system's appropriate setting is the operator of that
> system. Haphazardly increasing the limit every few years mainly
> reduces incentive for people to get this right.
>
> And people who test their software on 5.17 kernels will later find that
> it doesn't work on 5.16 and earlier, so they still need to tell their
> users to configure their systems appropriately. Until 5.16 is
> obsolete, by which time we're looking at increasing the default again.
>
> I don't see how this change gets us closer to the desired state:
> getting distros and their users to configure their systems
> appropriately.

Perfect is the enemy of good. This is a very simple change we can make
to improve the status quo, and I think that's worth doing. I do not have
time to develop a more sophisticated solution which steers the defaults
based on memory present, and I definitely don't have the time to
petition every distro to configure a better default for their particular
needs. This is the easiest way to get broad adoption for a better
default.