Re: [REQUEST] eliminate the rthal_critical_enter/exit() from rthal_irq_request()

Hi,

I haven't had access to my laptop during this week so the patches
follow only now.

Yet another issue remains that may lead to a deadlock under some circumstances:

- rt_intr_delete() calls xnintr_detach() while holding the "nklock".

- xnintr_detach() (with CONFIG_SMP) spins in xnintr_shirq_spin()
when a corresponding ISR is currently running.

- now this ISR calls any function that uses "nklock" (everything make
use of it) ... Bum!

I first thought about moving xnintr_detach() out of the locked section
in rt_intr_delete() but it somewhat breaks interface consistency ---
e.g. xeno_mark_delete() is called before the object is completely
destroyed.

Another approach would be to introduce a service like
xnintr_synchronize() and enfource the upper interfaces (e.g. skins) to
make use of it in their _delete() methods.

The problem here is that the xnintr_shirq - interface is not complete
and safe without xnintr_shirq_spin() on detaching step and it becomes
somewhat blured with the enforcement like "on SMP systems one should
always call xnintr_synchronize() right after calling xnintr_detach()".

So I'm still thinking how to fix it better...


--
Best regards,
Dmitry Adamushko

hal.c-irqrequest-noglock.patch
Description: Binary data

core.c-virtualizeirq.patch
Description: Binary data

intr.c-noglock.patch
Description: Binary data

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