[ltt-dev] [URCU RFC patch 0/3] call_rcu() performance improvements

[mathieu.desnoyers@efficios.com (Mathieu Desnoyers)]

Hi,

I did some benchmarking on the rbtree2 branch (on my rcu red black tree
implementation) and figured out some very important slowdown that were
due to the current call_rcu implementation. This patch series digs
through the problems I noticed and explains the solution. The three main
problems were:

- Lack of per-cpu affinity for per-cpu call_rcu threads.
- Use of pthread_cond, which requires a mutex, at each call_rcu
  execution to signal the call_rcu thread (heavy mutex contention).
- More delay than necessary between executions of the call_rcu thread in
  the wakeup-based scenario increased the cache footprint.

I'm proposing these patches as RFC. If you think they are acceptable,
I'll pull them into the liburcu mainline.

Comments are welcome,

Thanks,

Mathieu

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com