Some kernel developers recently have been trying to work around the massive, horrifying, long-term security holes that have recently been discovered in Intel hardware. In the course of doing so, there were some interesting comments about coding practices.
Christoph Hellwig and Jesper Dangaard Brouer were working on mitigating some of the giant speed sacrifices needed to avoid Intel's gaping security holes. And, Christoph said that one such patch would increase the networking throughput from 7.5 million packets per second to 9.5 million—a 25% speedup.
To do this, the patch would check the kernel's "fast path" for any
dma_direct_ops and replace them with a simple direct