Re: [RFC] Hierarchical BackOff Locks

Christoph Lameter
2005-06-24T17:53:08Z

On Wed, 22 Jun 2005, Zoltan Menyhart wrote:

> Can we consider instead of "cpu_to_node_map[(ia64_getreg(_IA64_REG_TP)->cpu)]"
> perhaps some "per_cpu__my_slock_idx" ?
>
> > + ia64_spinlock_val = ia64_cmpxchg4_acq(ia64_spinlock_ptr,
> > numa_node_id()+ 1, 0); \
>
> Instead of "numa_node_id()+ 1" perhaps some "per_cpu__my_slock_id" ?

I just tried to implement your proposed method but we will run into issues
with preemption. I would have preempt disable/enables or irq
disable/enables inline as well as in the contention handlers.