Messages in this thread | | | Subject | Re: [PATCH -rt] revert bh_lru_lock() to preempt_disable() | From | Daniel Walker <> | Date | Wed, 03 May 2006 13:47:37 -0700 |
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On Wed, 2006-05-03 at 22:47 +0200, Ingo Molnar wrote: > * Daniel Walker <dwalker@mvista.com> wrote: > > > The bh_lru_lock() was set to disable interrupt to protect from > > IPI's, which are only on SMP . So I don't think it's needed in UP > > PREEMPT_RT configs. > > 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 ?
Daniel
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