I'm wondering if vibe.d would be able to take advantage of the "maxcpus" kernel parameter, and using "pthreadsetaffinitynp" to use the inactive CPUs for worker tasks without interruption. I'm not sure if this should belong in libevent though.
This article was using Snort as an example, which is quite interesting because it can somewhat relate to vibe.d quite well:
http://blog.erratasec.com/2013/02/multi-core-scaling-its-not-multi.html#.UwQnPYUVRdQ
"For example, set “maxcpus=2”. This will cause Linux to use only the first two CPUs of the system. Sure, it knows other CPU cores exist, it just will never by default schedule a thread to run on them.
Then what you do in your code is call the “pthreadsetaffinitynp()” function call to put your thread on one of the inactive CPUs (there is Snort configuration option to do this per process). As long as you manually put only one thread per CPU, it will NEVER be interrupted by the Linux kernel. Only if you schedule two threads on a CPU will the interruption happen. Thus, you configure each Snort to run on its own dedicates Snort, and a lot of the jitter in IPS mode goes away."