On 07/14, Peter Zijlstra wrote: > > The current percpu-rwsem read side is entirely free of serializing > instructions at the cost of having a synchronize_sched() in the write > path. > > The latency of the synchronize_sched() is too high for some users > (cgroups), so provide a __percpu_init_rwsem(.bias) argument to forgot > this synchronize_sched() at the cost of forcing all readers into the > slow path, which has serializing instructions.
Oh well... I personally do not think this is what we want... Can't we just add the stupid rcu_sync_enter() into cgroup_init() at least for now? Yes, this means the unnecessary .sync() at boot time, but it will go away after cleanups I am going to send. Because, again, we will probably want to change this bias dynamically. Oleg.
