On 29 November 2012 21:21, Mark Kettenis <[email protected]> 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. >
indeed, freebsd originated drivers (age, ale, alc, jme, se, vte) and ex do this when allocation fails, but vic, xe when something is wrong with the packet. i'd argue that we certainly want to change vic and xe since it has little to do with any input queue whatsoever. but on the other hand adding code to netstat to handle a handful of rather unpopular nics seems to be an overkill. and spreading the if_iqdrops love across the tree doesn't sound like a great use of time.
