Re: [RT PATCH] sched: rt: fix two possible deadlocks in push_irq_work_func

[Thomas Gleixner]

On Sun, 15 Nov 2015, Thomas Gleixner wrote:
> On Sat, 14 Nov 2015, yjin wrote:
> > > > Use raw_spin_{un,}lock_irq{save,restore} in push_irq_work_func() to
> > > > prevent following potentially deadlock scenario:
> > > Ug. No, the real fix is that the irq work is to be run from hard
> > > interrupt context.
> > But if so, we shouldn't call irq_work_tick() in run_timer_softirq(), right?
> 
> The work is marked IRQ_WORK_HARD_IRQ so it should be run from hard irq
> context. We only run the work, which is not marked IRQ_WORK_HARD_IRQ
> from the softirq on RT.

Which does not happen on MIPS as it uses the generic
arch_irq_work_has_interrupt() implementation which returns 'false'.

Thanks,

	tglx
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