Re: [PATCH 2/5] forcedeth: interrupt handling cleanup

["Yinghai Lu" <yhlu.kernel@gmail.com>]

On 10/7/07, Jeff Garzik <jeff@garzik.org> wrote:
> Yinghai Lu wrote:
> > On 10/6/07, Jeff Garzik <jeff@garzik.org> wrote:
> >> commit a606d2a111cdf948da5d69eb1de5526c5c2dafef
> >> Author: Jeff Garzik <jeff@garzik.org>
> >> Date:   Fri Oct 5 22:56:05 2007 -0400
> >>
> >>     [netdrvr] forcedeth: interrupt handling cleanup
> >>
> >>     * nv_nic_irq_optimized() and nv_nic_irq_other() were complete duplicates
> >>       of nv_nic_irq(), with the exception of one function call.  Consolidate
> >>       all three into a single interrupt handler, deleting a lot of redundant
> >>       code.
> >>
> >>     * greatly simplify irq handler locking.
> >>
> >>       Prior to this change, the irq handler(s) would acquire and release
> >>       np->lock for each action (RX, TX, other events).
> >>
> >>       For the common case -- RX or TX work -- the lock is always acquired,
> >>       making all successive acquire/release combinations largely redundant.
> >>
> >>       Acquire the lock at the beginning of the irq handler, and release it at
> >>       the end of the irq handler.  This is simple, easy, and obvious.
> >>
> >>     * remove irq handler work loop.
> >>
> >>       All interesting events emanating from the irq handler either have
> >>       their own work loops, or they poke a timer into action.
> >>
> >>       Therefore, delete the pointless master interrupt handler work loop.
> >>
> >>     Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
> >>
> Do you have ideas/suggestions for a different method?

in the e1000 driver, it has seperate handler for msi and ioapic.

but in forcedeth, the nv_nic_irq_optimized keep check msi_flags...,
with num of msi interrupt number, that could cause cpu loading get a
little bit high..., even the network performance is ok.

YH