Phoronix published a review on the Docker Performance With KPTI Page Table Isolation Patches (Meltdown Fix) A quote from the article:

Overall most of our benchmarks this week of the new Linux Kernel Page Table Isolation (KPTI) patches coming as a result of the Meltdown vulnerability have showed minimal impact overall on system performance. The exceptions have obviously been with workloads having high kernel interactions like demanding I/O cases and in terms of real-world impact, databases. But when testing VMs there's been some minor impact more broadly than bare metal testing and also Wine performance has been impacted. The latest having been benchmarked is seeing if the Docker performance has been impacted by the KPTI patches to see if it's any significant impact since overall the patched system overhead certainly isn't anything close to how it was initially hyped by some other media outlets.

 Docker Performance With KPTI Page Table Isolation Patches (Meltdown Fix) @ Phoronix