[gentoo-user] How safe is it to change vanilla-USE-Flag in glibc?

[Franz Fellner]

Hey all,

I have issues with some prgrams eating too much memory. This seems to be related to glibc not trimming as necessary which results in way too much memory still occupied by the program after free()ing memory.
I can't use gcc (specifically g++) with quite some apps now because it starts collecting memory (+swap) until everything falls apart, and I finally came to the conclusion also gcc might suffer from bad trimming behaviour.
As glibc is the package that implements free I want to have a closer look at it. The first idea is to get rid of Gentoo patches which are controlled by USE="vanilla". Playing around with glibc might destroy my system. Downgrades are already unsupported. So my question:

Can I safely switch from -vanilla to +vanilla in glibc?

This is how glibc currently is installed:
sys-libs/glibc-2.23-r2(multilib rpc -audit -caps -debug -gd -hardened -nscd -profile -selinux -suid -systemtap -vanilla CROSSCOMPILE_OPTS="-headers-only")

Thx for your help
Franz