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

From: Ingo Molnar
Date: Wed May 03 2006 - 16:42:28 EST



* Daniel Walker <dwalker@xxxxxxxxxx> 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)

Ingo
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