Re: [patch] rt: res_counter fix, v2

Peter Zijlstra
2009-02-12T17:29:28Z

On Thu, 2009-02-12 at 22:28 +0530, Balbir Singh wrote:

> > _nort() will just turn them into NOPs in essence.
> >
> > The question is, are these local IRQ flags manipulations really needed
> > in this code, and if yes, why?
>
> We needed the local IRQ flags, since these counters are updated from
> page fault context and from reclaim context with lru_lock held with
> IRQ's disabled. I've been thinking about replacing the spin lock with
> seq lock, but have not gotten to it yet.

Ah, in that case we can get away with _nort I think, as both those
contexts are preemptable on -rt.