Re: [PATCH -rt] revert bh_lru_lock() to preempt_disable()

[Daniel Walker]

On Wed, 2006-05-03 at 23:01 +0200, Ingo Molnar wrote:
> * Daniel Walker <dwalker@xxxxxxxxxx> wrote:
> 
> > > i agree that this is a problem, but the fix is incorrect. What would be 
> > > the right approach is to convert the PER_CPU bh_lrus to PER_CPU_LOCKED, 
> > > and to use the appropriate primitives to use them. That automatically 
> > > makes this code rt-safe. (it isnt right now)
> > 
> > Hmm, in UP it should be safe to access per cpu data under either a 
> > preempt_disable or local_irq_disable . I'm not sure how RT changes 
> > that .. Is there some other part of the code that isn't rt-safe, which 
> > I've overlooked ?
> 
> hm, you are right - that code can be in a preempt-off section. I've 
> applied your patch.

We could switch it to locked types if it's a latency concern..

Daniel

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