Date: Tue, 4 Sep 2018 09:28:15 -0700 From: John-Mark Gurney <jmg@funkthat.com> To: Marko Zec <zec@fer.hr> Cc: Vincenzo Maffione <v.maffione@gmail.com>, Luigi Rizzo <rizzo@iet.unipi.it>, "freebsd-net@freebsd.org" <net@freebsd.org> Subject: Re: vale and netmap module questions Message-ID: <20180904162815.GA75530@funkthat.com> In-Reply-To: <20180904164303.68c43b6e@x23> References: <20180901014953.GV45503@funkthat.com> <CA%2B_eA9gH_uzxV_YLBH1XdM-ygPUxXzD_W9_b45jTmeY-t0bQKg@mail.gmail.com> <20180901211123.GZ45503@funkthat.com> <20180904164303.68c43b6e@x23>
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Marko Zec wrote this message on Tue, Sep 04, 2018 at 16:43 +0200:
> On Sat, 1 Sep 2018 14:11:23 -0700
> John-Mark Gurney <jmg@funkthat.com> wrote:
> > Vincenzo Maffione wrote this message on Sat, Sep 01, 2018 at 22:25
> > +0200:
> ...
> > > On x86_64 netmap is not built as a module, so everything works
> > > fine. I don't see any reason why it should be a module in aarch64.
> >
> > Well, sys/modules/netmap exists... If it isn't planned on ever being
> > made to work, it should be removed so people don't get confused, or
> > at least marked broken so it doesn't get built...
> >
> > I built it manually because it was quicker than recompiling an entire
> > kernel and rebooting...
>
> Hi John-Mark,
>
> out of curiosity I tested all four kernel config combinations with
> "device netmap" and "options VIMAGE" being on and off (both are on by
> default now in GENERIC) on amd64 @r338446, and found that kldloading
> netmap.ko can't provoke a panic. Was there a particular sequence of
> commands issued after kldloading netmap which led to the crash you
> reported earlier?
Nope. I would kldload netmap, and then run the tcpdump command listed
in the original report, and it would just panic...
Also note that my panic was on arm64, NOT amd64.. so it could be
something platform specific...
> Nevertheless, note that building the kernel without "device netmap" is
> borderline pointless even if netmap core built as a kld module works, as
> this will result in all the drivers being built without the required
> netmap bits, which means they will only work in the painfully slow
> "emulation" mode with netmap.
I was only doing it to test something out quickly..
> Perhaps the panic you stepped into was related to the emulation mode
> being used with netmap, instead of using the native netmap hooks in
> device drivers? Or maybe was it vale + VNET related?
All I know was that it was the arm64 GENERIC kernel + module netmap
+ running tcpdump w/ that command... Nothing special configured, just
a single ethernet interface configured w/ DHCP. No firewall configured,
just sshd and ntpd enabled..
--
John-Mark Gurney Voice: +1 415 225 5579
"All that I will do, has been done, All that I have, has not."
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