/system/bin/mediaserver and /system/bin/drmserver dont want these but Android disagrees I used this link Use Adb to disable Media Server

hoping to permanenenly disable the battery hogging media server process . It did not work Mediaserver still runs on my Android 4.4 Jiayu S3 phone as /system/bin/mediaserver and I found another just as pricky process called /system/bin/drmserver which shows up on adb # top .
So I mounted the /system in RW mode and removed -x from them both. 
After that I killed the existing processes for these binaries. The phone just froze .  After a force restart it will NOT BOOT until I restored the -x bit again ( restored execute ) .
What do these do . How do I  ensure they don't run if they are not needed.
This is a really old question but I have an answer for anyone wondering.If you do not care about playing DRM-protected content, just replace /system/bin/drmserver with an executable file that does nothing (e.g. just sleeps forever). Example: File someone made for a Magisk module that disabled DRM