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    SubjectRe: Info: NAPI performance at "low" loads
       From: Jeff Garzik <>
    Date: Tue, 17 Sep 2002 17:54:42 -0400

    David S. Miller wrote:
    > Any driver should be able to get the NAPI overhead to max out at
    > 2 PIOs per packet.

    Just to pick nits... my example went from 2 or 3 IOs [depending on the
    presence/absence of a work loop] to 6 IOs.

    I mean "2 extra PIOs" not "2 total PIOs".

    I think it's doable for just about every driver, even tg3 with it's
    weird semaphore scheme takes 2 extra PIOs worst case with NAPI.

    The semaphore I have to ACK anyways at hw IRQ time anyways, and since
    I keep a software copy of the IRQ masking register, mask and unmask
    are each one PIO.
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