>>>>> "Jon" == Jon Smirl <[EMAIL PROTECTED]> writes:
>> The scenario I'm thinking about with these patches are things like >> low-latency user-level networking between nodes in a cluster, where >> for good performance even with a kernel driver you don't want to >> share your interrupt line with anything else. Jon> The code needs to refuse to install if the IRQ line is shared. It does. The request_irq() call explicitly does not include SA_SHARED in its flags, so if the line is shared, it'll return an error to user space when the driver tries to open the file representing the interrupt. Jon> Also what about SMP, if you shut the IRQ off on one CPU isn't it Jon> still enabled on all of the others? Nope. disable_irq_nosync() talks to the interrupt controller, which is common to all the processors. The main problem is that it's slow, because it has to go off-chip. -- Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au The technical we do immediately, the political takes *forever* - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
