--- On Tue, 8/18/09, Julian Elischer <jul...@elischer.org> wrote:
> From: Julian Elischer <jul...@elischer.org> > Subject: Re: [PATCH] Fix for e1000 (em/igb) NOARP issue [Was Re: em(4): > sending ARP regardless of NOARP flag] > To: d...@delphij.net > Cc: pyu...@gmail.com, "Barney Cordoba" <barney_cord...@yahoo.com>, "David > Christensen" <davi...@broadcom.com>, "freebsd-net@freebsd.org" > <freebsd-net@freebsd.org>, "Jack Vogel" <jfvo...@gmail.com>, "Jack F Vogel" > <j...@freebsd.org>, yong...@freebsd.org > Date: Tuesday, August 18, 2009, 6:55 PM > Xin LI wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > Barney Cordoba wrote: > >> --- On Tue, 8/18/09, Pyun YongHyeon <pyu...@gmail.com> > wrote: > >> > >>> From: Pyun YongHyeon <pyu...@gmail.com> > >>> Subject: Re: [PATCH] Fix for e1000 (em/igb) > NOARP issue [Was Re: em(4): sending ARP regardless of NOARP > flag] > >>> To: "Xin LI" <delp...@delphij.net> > >>> Cc: "Barney Cordoba" <barney_cord...@yahoo.com>, > "David Christensen" <davi...@broadcom.com>, > "d...@delphij..net" > <d...@delphij.net>, > "freebsd-net@freebsd.org" > <freebsd-net@freebsd.org>, > "Jack Vogel" <jfvo...@gmail.com>, > "Jack F Vogel" <j...@freebsd.org>, > yong...@freebsd.org, > "Julian Elischer" <jul...@elischer.org> > >>> Date: Tuesday, August 18, 2009, 5:49 PM > >>> On Tue, Aug 18, 2009 at 02:03:37PM > >>> -0700, Xin LI wrote: > >>>> -----BEGIN PGP SIGNED MESSAGE----- > >>>> Hash: SHA1 > >>>> > >>>> Hi, Jack, > >>>> > >>>> I have looked into the code history and > found that > >>> sys/dev/em/if_em.c,v > >>>> 1.119 has introduced the arp_ifinit() call > in order to > >>> fix the problem > >>>> that if_em won't send ARP when IP address > is changed. > >>>> > >>>> I think we can further improve it as > attached, say, > >>> only do it when > >>>> IFF_NOARP is not set. This should > have no effect > >>> for usual > >>>> configuration but fix the problem when > NOARP is the > >>> desired behavior. > >>> That change was introduced by me. I guess the > root cause of > >>> the > >>> problem was long initialization time of > hardware which in > >>> turn > >>> resulted in unbearable boot time when > multiple-alias > >>> addresses are > >>> assigned to em(4). I don't remember > details,though. > >>> > >>> Since we're in the release cycle, the change > you suggested > >>> would be > >>> quick fix for 8.0. I think em(4)/igb(4) should > remove > >>> SIOCSIFADDR > >>> handling in driver which is layering > violation. > >> There are 2 kinds of programmers; those who do > things "correctly', > >> and those that do things that work. > >> > >> 99.99999% of the people will be using ARPs, so > don't be silly and > >> break the driver to solve a case that almost > no-one cares about please. > > > > Cisco.Ironport runs 50% (2 out of 4) of their em > interfaces in noarp > mode. Ah, are they running Jack's drivers unmodified? Seems unlikely. NOARP does work. Does your network catch on fire if the interface sends an ARP out? Does equipment start failing like dominos? My point was don't make ARPs not work (the reason the "hack" is in there is to make something work better) to preserve some fantasy of "layering" that went out with the 8-track player. The check for the NOARP flag is a better solution until the subsystem works the way its supposed to work. Barney _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
