Messages in this thread | | | Date | Wed, 1 Jun 2005 21:39:06 +0200 | From | Ingo Molnar <> | Subject | Re: RT patch acceptance |
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* Andrea Arcangeli <andrea@suse.de> wrote:
> > So if PREEMPT-RT would use a soft cli/sti emulation, no problem should > > arise. > > So I wonder why it doesn't do that and it leaves local_irq_disable > uncovered [...] > > Perhaps that's planned and not yet implemented?
yes. As i said in an earlier mail:
> > (there are still some ways to introduce latencies into PREEMPT_RT, > > but they are not common and we are working on ways to cover them > > all.)
local_irq_disable() is one way, preempt_disable() is another way. Adding asm("cli") to your driver is a third way. In practice these items are not a big issue, so i'm not yet covering them. It's a small detail. Check the amount of local-irq-disable instances in the driver space vs. spinlock use.
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