Call for stge(4) testers
Pyun YongHyeon
pyunyh at gmail.com
Mon Jul 10 03:54:39 UTC 2006
On Sun, Jul 09, 2006 at 08:07:55PM -0700, John-Mark Gurney wrote:
> Pyun YongHyeon wrote this message on Mon, Jul 10, 2006 at 11:27 +0900:
> > On Sat, Jul 08, 2006 at 09:24:23PM -0700, Matthew Jacob wrote:
> > > Jason THorpe did one for NetBSD.
> > >
> > > I did one for Solaris. Nice chip. Too bad it wasn't more popular.
> >
> > I'm satisfied with the performance and easy interface for the chip.
> > But the lack of Tx interrupt moderation and extra accesses to a
> > status register to check which kind of Tx errors were occurred are
> > serious fault. Since the the error condition uses the same status
> > bit in interrupt status register it's hard to distingush failures
> > from sucess without extra register accesses.
>
> bah, tx interrupts are so last century... there isn't any reason to
> have them... just schedule a timeout or wakeup a thread when the
> number of tx descriptors are low.. and if you ran out, you could
> even do the minimal work to free them up right in place...
>
I'm afraid it's not that simple. If we just reclaim Tx descriptors
based only on number of available Tx descriptors it would hold a lot
of mbuf chains in memory for a long time. My approach to solve this
is hybrid(a watermark which control when to raise a Tx interrupt
plus clean up handler which is called every hz)
--
Regards,
Pyun YongHyeon
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