On 29 November 2012 21:37, Claudio Jeker <[email protected]> wrote:
> On Thu, Nov 29, 2012 at 09:21:49PM +0100, Mark Kettenis wrote:
>> > Date: Thu, 29 Nov 2012 20:49:00 +0100
>> > From: Claudio Jeker <[email protected]>
>> >
>> > On Thu, Nov 29, 2012 at 11:50:09AM -0500, Kenneth R Westerback wrote:
>> > > On Thu, Nov 29, 2012 at 04:41:09PM +0100, Mike Belopuhov wrote:
>> > > > hi,
>> > > >
>> > > > drivers ex age alc ale jme se vic vte xe upl and octeon/cmac
>> > > > make use of the if_iqdrops counter that is not shown by any of our
>> > > > tools (like netstat).  looks like most of its usage comes from
>> > > > freebsd where they show it in the "netstat -di" output in a new
>> > > > column.  do we want to do that or just convert them to if_ierrors
>> > > > since 90% of our drivers do only if_ierrors.  there's also doesn't
>> > > > seem to be any rule when to use if_iqdrops (well, since in most
>> > > > drivers there's no input queueing -- check out upl(4) :)
>> > > >
>> > > > the diff below changes all the drivers in our tree to use
>> > > > if_ierrors instead of if_iqdrops.  i've decided to leave
>> > > > octeon/cmac driver as is because if_iqdrops is used for
>> > > > debugging purposes there.
>> > > >
>> > > > ack?  nack?  meh?
>> > >
>> > > Seems like a good idea to me to not lose those errors. I have
>> > > no great desire for a new column in netstat, but no great
>> > > antagonism to one either.
>> > >
>> >
>> > I guess the idea is to show which interfaces are overloading the input
>> > queues. At least that is my interpretation of if_iqdrops (input queue
>> > drops). In a away it makes sense but I'm not to attached to it. I would
>> > prefer we would actually print out the output queue drops on the interface
>> > queue.
>>
>> Actually, in the network (hardware) drivers this is used to flag the
>> "oh shit, I cannot allocate a new mbuf, let's drop the packet I just
>> received such that I can keep my ring filled" conditions.  It is
>> somewhat useful to be able to distinguish this condition from packets
>> that were dropped by the hardware because they were not received
>> correctly.
>
> True, it would also help in mclgeti drivers to distinguish between packets
> that got dropped because of errors or because of mclgeti.
>

but we don't increment ierrors when mclgeti fails.

Reply via email to