Re: [RFC PATCH] introduce sys_membarrier(): process-wide memorybarrier (v5)

[Steven Rostedt]

On Thu, 2010-01-21 at 11:22 -0500, Mathieu Desnoyers wrote:
> * Steven Rostedt (rostedt@xxxxxxxxxxx) wrote:

> > You may also need spin_lock_irqsave, et al. variants too.
> 
> Yep, or we simply use the local_irq_save/restore separately. That could
> be a good idea given that only few specialized sites are affected.

If it gets used more often, then we need to consider RT. RT modifies
spin_lock_irqsave into a standard mutex that does not disable
interrupts. But if something does:

	local_irq_save(flags);
	spin_lock_mb(&lock);
	[...]

Then it will break RT (if lock is to be converted).

-- Steve


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