On Tue, 2007-03-20 at 15:24 +0530, Daniel Rodrick wrote: > On 3/19/07, Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote: > > > > > > > > i thought you couldn't use semaphores from interrupt context, anyway. > > > can someone clarify this? thanks. > > > > you can release semaphores in interrupt context, and you can do a > > trylock in interrupt context as well. > > > > When we increment / release a semaphore in interrupt context, in the > process of releasing the semaphore, won't the kernel try to reschedule > if a higher priority process was waiting on the semaphore? not until you exit the interrupt (and if you have kernel preempt disabled and are in kernel mode, not until you exit back to userspace). The reschedule point is on the go-back-to-userspace code... not in the actual irq side of things. -- if you want to mail me at work (you don't), use arjan (at) linux.intel.com Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
