Feature request by Andras Korn:

CONFIG_LOG_BUF_SHIFT used to be too small in at least grml64 Lackdose-Allergie; 
thus, after booting, /var/log/dmesg didn't contain all messages.

Note by mika:

We should raise CONFIG_LOG_BUF_SHIFT from '17' to '18' with our next kernel 
version.