[lkml]   [2003]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: The well-factored 386
    On Tue, Jul 29, 2003 at 01:59:41PM +0100, you [John Bradford] wrote:
    > > > I didn't realise he was talking about an x86 emulator. I thought he
    > > > was analyzing real hardware.
    > > >
    > > > The one thing that made it on-topic for me was his quiet suggestion
    > > > that "forreal" mode interrupts are faster, and that it might, perhaps,
    > > > be possible to modify a Linux kernel to run in that mode - to take
    > > > advantage of the faster interrupts.
    > >
    > > That would have to be a kernel for very special use. The "forreal"
    > > mode has protection turned off. As far as I know, that
    > > means any user process can take over the cpu as if
    > > it was running in kernel mode.
    > >
    > > Perhaps useful for some embedded use with only a couple well-tested
    > > processes running. Still, a programming error could overwrite
    > > kernel memory instead of segfaulting.
    > Anything that's single user and non-networked isn't beyond the realms
    > of feasability - it would be useful for a games console, or high
    > performance graphics work.
    > It would be an interesting project, but what concerns me is how well
    > implemented these non-standard modes actually are. It's possible that
    > there are processors out there that don't work reliably with them, or
    > don't implement them at all.

    Have you looked at Kernel Mode Linux?

    I don't think it uses "forreal" mode, but it allows running selected user
    processes in kernel mode thus getting rid of system call overhead.

    [Note to Toshiyuki Maeda: the complete thread is at
    in case you want to catch some context. The "forreal" idea is mentioned in
    the first mail of the thread.]

    -- v --
    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 13:47    [W:0.021 / U:4.460 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site