[lkml]   [2005]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: User mode drivers: part 1, interrupt handling (patch for 2.6.11)
    >>>>> "Jon" == Jon Smirl <> writes:

    Jon> On Fri, 11 Mar 2005 14:36:10 +1100, Peter Chubb
    Jon> <> 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 peterc AT
    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
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 14:11    [W:0.019 / U:8.552 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site