Messages in this thread | | | Date | Mon, 06 Jul 2015 19:09:00 +0200 | From | Eric Auger <> | Subject | Re: [RFC v2 3/6] irq: bypass: Extend skeleton for ARM forwarding control |
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On 07/06/2015 05:57 PM, Paolo Bonzini wrote: > > > On 06/07/2015 17:35, Eric Auger wrote: >>>> diff --git a/kernel/irq/bypass.c b/kernel/irq/bypass.c >>>>>> index 5d0f92b..efadbe5 100644 >>>>>> --- a/kernel/irq/bypass.c >>>>>> +++ b/kernel/irq/bypass.c >>>>>> @@ -19,6 +19,42 @@ static LIST_HEAD(producers); >>>>>> static LIST_HEAD(consumers); >>>>>> static DEFINE_MUTEX(lock); >>>>>> >>>>>> +/* lock must be hold when calling connect */ >>>> >>>> If a lock must be held while callbacks are called, you have to document >>>> that producers and consumers must _not_ call back into the IRQ bypass >>>> manager. (If they have to, you have to document explicitly "This >>>> function can be called from producer and consumer callbacks" whenever >>>> relevant). >> OK Thanks > > Also, please document on functions that take the irq bypass mutex that > they can sleep. In fact irq_bypass_{,un}register_{producer,consumer} > need kerneldoc comments. > > The good thing is that this helps a bit forming a lock hierarchy across > the subsystems, for example irq bypass mutex outside vfio_platform_irq > spinlock, because you cannot have a spinlock inside the mutex. I think > that all of your six callbacks are fine.
arghh, no that's wrong then. I have plenty of them in the KVM/arm vgic part :-(
Eric > > Paolo >
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