On Mon, 14 Jan 2013, Mark Rutland wrote: > On Mon, Jan 14, 2013 at 11:50:55AM +0000, Thomas Gleixner wrote: > > On Mon, 14 Jan 2013, Mark Rutland wrote: > > > > > On Mon, Jan 14, 2013 at 11:06:31AM +0000, Thomas Gleixner wrote: > > > > On Wed, 9 Jan 2013, Mark Rutland wrote: > > > > > +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST > > > > > +extern int tick_receive_broadcast(void); > > > > > +#else > > > > > +static inline int tick_receive_broadcast(void) > > > > > +{ > > > > > + return 0; > > > > > +} > > > > > > > > What's the inline function for? If an arch does not have broadcasting > > > > support it should not have a receive broadcast function call either. > > > > > > That was how this was originally structured [1], but Santosh suggested > > > this > > > would break the build for !GENERIC_CLOCKEVENTS_BROADCAST [1]. It means > > > that the > > > arch-specific receive path (i.e. IPI handler) doesn't have to be #ifdef'd, > > > which makes it less ugly. > > > > Hmm. If you want to keep the IPI around unconditionally the inline > > makes some sense, though the question is whether keeping an unused IPI > > around makes sense in the first place. I'd rather see a warning that > > an unexpected IPI happened than a silent inline function being called. > > How about I add a warning (e.g. "Impossible timer broadcast received.") and > return -EOPNOTSUPP when !GENERIC_CLOCKEVENTS_BROADCAST?
You still need to do something with the return value in the arch IPI code, right? > > > > Is anything going to use the return value? > > > > > > I'd added this after looking at the x86 lapic timers, where interrupts > > > might > > > remain pending over a kexec, and lapic interrupts come up before timers > > > are > > > registered. The return value is useful for shutting down the timer in > > > that case > > > (see x86's local_apic_timer_interrupt). > > > > Right, though then you need to check for evt->event_handler as well. > > I thought this previously also [1], but I couldn't find any path such that a > tick_cpu_device would have an evtdev without an event_handler. We always set > the > handler before setting evtdev, and alway wipe evtdev before wiping the > handler. > > Have I missed something? That's an x86 specific issue. Though we could try and make that functionality completely generic. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/