* Dave Chinner <david@xxxxxxxxxxxxx> wrote: > On Thu, Dec 10, 2009 at 08:59:47AM +0100, Ingo Molnar wrote: > > * Rafael J. Wysocki <rjw@xxxxxxx> wrote: > > > On Wednesday 09 December 2009, Ingo Molnar wrote: > > > > * Rafael J. Wysocki <rjw@xxxxxxx> wrote: > > > > > On Tuesday 08 December 2009, Alan Stern wrote: > > > > > > On Tue, 8 Dec 2009, Rafael J. Wysocki wrote: > > > > > > > > > > > > > BTW, is there a good reason why completion_done() doesn't use spin_lock_irqsave > > > > > > > and spin_unlock_irqrestore? complete() and complete_all() use them, so why not > > > > > > > here? > > > > > > > > > > > > And likewise in try_wait_for_completion(). It looks like a bug. Maybe > > > > > > these routines were not intended to be called with interrupts disabled, > > > > > > but that requirement doesn't seem to be documented. And it isn't a > > > > > > natural requirement anyway. > > When I implemented them they were not called from anywhere that > disabled interrupts. IIRC the main reason I used spin_lock_irq() > was because that is what wait_for_completion() used at the time.... Obviously wait_for_competion() as a non-atomic API that can block will (and should) use _irq() - but atomic variants (complete, but also the try-wait thing) use irqsafe methods. A fair portion of completions happen in IRQ context. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
