I tried to burn a 2.8GB DVD on a beta3 system. Result was:

# growisofs -dvd-compat -Z /dev/sr0=image.iso
:-( unable to anonymously mmap 33554432: Resource temporarily unavailable

The culprit is it first does 

getrlimit(RLIMIT_MEMLOCK, {rlim_cur=32*1024, rlim_max=32*1024}) = 0
setrlimit(RLIMIT_MEMLOCK, {rlim_cur=36864*1024, rlim_max=36864*1024}) = 0
mlockall(MCL_CURRENT|MCL_FUTURE)        = 0
... and then later ...
mmap(NULL, 33554432, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1 EAGAIN (Resource temporarily unavailable)

The rlimit set is only ~36MB and the allocation is 33.5MB and with some
other allocations it's too much and the mmap fails.

Either the RLIMIT_MEMLOCK should be dropped or it needs to be increased
to the maximum amount of memory that can be allocated.