8-CPU (SMP) #s for lockfree rtcache

Quoted 2 lines · Andi Kleen

And gain tons of new atomic_incs and decs everywhere in the process? I would prefer RCU.

Lots of people write drivers, many of them not SMP kernel locking gurus who have time to understand RCU and when they can or cannot sleep, and what happens if their unload is pre-empted and RCU is in use. The kernel core has to provide a clean easy interface. The network code is a superb example of this. All the hard thinking is done outside of the driver, at least unless you choose to join in that thinking to get the last scraps of performance.