Date: Fri, 18 Nov 2011 12:53:52 -0800 From: Maksim Yevmenkin <maksim.yevmenkin@gmail.com> To: Juli Mallett <jmallett@freebsd.org> Cc: freebsd-net <freebsd-net@freebsd.org> Subject: Re: confused with if_baudrate Message-ID: <CAFPOs6qGgmiaEdLHhmkZ7aQvjhv836-kiWXw5X22xt5cvmRtfw@mail.gmail.com> In-Reply-To: <CACVs6=_HOGNhc84hL7yN1NxmS%2BEO5ykEQhOAQuBvjiyxe9JPrg@mail.gmail.com> References: <CAFPOs6oVZ-%2B8%2B37SoDQmSawAOYnZBAQbLstPaJ5i3wScd8WVeQ@mail.gmail.com> <CACVs6=_HOGNhc84hL7yN1NxmS%2BEO5ykEQhOAQuBvjiyxe9JPrg@mail.gmail.com>
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On Thu, Nov 17, 2011 at 1:39 PM, Juli Mallett <jmallett@freebsd.org> wrote: > On Thu, Nov 17, 2011 at 13:12, Maksim Yevmenkin > <maksim.yevmenkin@gmail.com> wrote: >> hello, >> >> i'm a little bit confused about if_baudrate. from system headers >> >> #define if_baudrate =A0 =A0 if_data.ifi_baudrate >> >> and >> >> u_long =A0ifi_baudrate; =A0 =A0 =A0 =A0 =A0 /* linespeed */ >> >> so, i'm taking this as if_baudrate really should be an interface line >> speed in megabits per second. am i correct? if so, then it appears >> that at least some drivers lie about true line speed. for example from >> ixgbe(4) >> >> =A0 =A0 =A0 =A0ifp->if_baudrate =3D 1000000000; >> >> it looks like its order of magnitude lower (i.e. 1 gigabit per second >> instead of 10 gigabits per second). am i missing something here or its >> just a typo? > > ixgbe's developer is excessively concerned about overflow on 32-bit > hosts (and unwilling to correct it under a preprocessor conditional), > unlike several of the other 10GbE driver developers, although I think > one 10GbE driver opts to omit if_baudrate entirely. well, this is unfortunate as if_baudrate reported as part of ifmib, so, when interface is monitored over snmp value of ifSpeed and HCOutSpeed can not be trusted :( thanks, max
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