Re: Is there spinlocks/semaphores available for drivers?

[Matthew Dillon]

:And would there still be areas of the kernel that disable multiple
:interrupts, perhaps CAM or the network stack for instance?  What do
:all the splbio and splnet calls translate into in this new scheme?
:
:-- 
:Dan Eischen

    The entire design of the kernel is currently predicated on the spl*()
    mechanism.  We obviously can't rip it out in a day.  I'm guessing it 
    will probably take two years ... or never if we can eek out sufficient
    performance with it still in place.

    I think there is a good chance we can reap the performance benefits 
    without ripping the spl*() API to shreads, even if we have to rewrite
    the cpl mechanism that runs the show under the hood.  The system most
    likely to be rewritten to avoid spl*() (under normal operation) is
    the network subsystem.  That alone will give us a big boost.

        Network subsystem       easy
        Disk subsystem          hard
        VM subsystem            really hard

    I outline how the current cpl mechanism can be used almost verbatim
    in an interrupt-thread environment in my SMP document, under
    'interrupt sequencing'.

        http://www.backplane.com/FreeBSD4/smp-api.html

                                        -Matt
                                        Matthew Dillon 
                                        <[EMAIL PROTECTED]>


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