>>>>> "Jon" == Jon Smirl <[EMAIL PROTECTED]> writes:
Jon> On Fri, 11 Mar 2005 14:36:10 +1100, Peter Chubb Jon> <[EMAIL PROTECTED]> wrote: >> As many of you will be aware, we've been working on infrastructure >> for user-mode PCI and other drivers. The first step is to be able >> to handle interrupts from user space. Subsequent patches add >> infrastructure for setting up DMA for PCI devices. Jon> I've tried implementing this before and could not get around the Jon> interrupt problem. Most interrupts on the x86 architecture are Jon> shared. Disabling the IRQ at the PIC blocks all of the shared Fortunately, most interrupts on IA64, ARM, etc., are unshared. And with PCI-Express, the problem will go away. Even on X86, things aren't all bad: one can usually find a PCI slot which doesn't share interrupts with anything you care about. 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. -- 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/
