Add configuration option to set tuning at runtime
Description
Hi, In current bind you can change tuning value only at buildtime with configure script option. This is a unfortunate for distributions which provide bind package. If you set tuning value in package during its build then you force all its users to use it. It would be better if configure script would set only default value and users would have a way how to change it as they like. This is important because there is a big difference in memory consumption between large and small tuning. Some users would like to have large tuning enabled because they are running big dns server which needs to be as fast as possible and others would like to have small tuning because they want bind to run with a smaller amount of memory.
Request
Configuration option in named.conf which could override the tuning value would be great. If you would be open to this change i could provide patch.
Links / references
https://bugzilla.redhat.com/show_bug.cgi?id=1578051
NOTE: At first we were investigating this as a memory bug but then we verified that the glibc allocators behaviour is normal and the memory consumption with large tuning is just so big.