From: Gregg Levine <gregg.drwho8@gmail.com>
To: Larry McVoy <lm@mcvoy.com>
Cc: tuhs@tuhs.org
Subject: Re: [TUHS] A/UX [was Linux is on-topic]
Date: Mon, 20 Jul 2020 22:30:03 -0400 [thread overview]
Message-ID: <CAC5iaNFjqdG+sfxbTtir=f5-5PPpvO_9adWvnDjkf_fpm=HSNw@mail.gmail.com> (raw)
In-Reply-To: <20200721015057.GV26294@mcvoy.com>
Hello!
Larry? I'm surprised. I've worked with QNX a few times. I also grok
that you're one who has mad respect for QNX. Because I'm one also.
It's an interesting OS,
-----
Gregg C Levine gregg.drwho8@gmail.com
"This signature fought the Time Wars, time and again."
On Mon, Jul 20, 2020 at 9:53 PM Larry McVoy <lm@mcvoy.com> wrote:
>
> On Mon, Jul 20, 2020 at 06:54:40AM -0600, Andrew Warkentin wrote:
> > On 7/20/20, Larry McVoy <lm@mcvoy.com> wrote:
> > > This isn't quite the same but Victor Yodaiken wrote a real time kernel
> > > that ran all of Linux as a user process. Super cool idea and it worked
> > > great, he would demo it sampling the parallel port while Linux was running
> > > some X11 perf thing, tarring up /usr and untarring on nfs://server/tmp/usr
> > > and doing a ftp transfer. Basically beating the crap out of Linux as
> > > hard as he could while running a real time sampler and it never missed.
> > >
> > > Clem should pay attention, in my opinion, this is how you do Unix and
> > > real time. Because Unix is time sharing and throughput, that is the
> > > opposite of what real time is. Wedging real time into Unix is a mistake.
> > >
> >
> > QNX manages to do realtime fairly decently while still being
> > Unix-like, although it's certainly not a conventional Unix. With a
> > multi-server OS with a properly designed microkernel, it is possible
> > for realtime threads to more or less ignore the fact that they're
> > running on a Unix-like OS (provided that they can access some kind of
> > IPC API that closely matches that of the kernel) since all the OS
> > services other than the microkernel are running beside them at
> > non-realtime priorities, and not underneath them as in a conventional
> > OS. It's kind of doing the same thing as running a Unix kernel as a
> > process under a realtime kernel, but the Unix environment is
> > implemented by servers and libraries instead of a monolithic kernel.
>
> QNX is awesome.
>
> I was friends with Dan Hildebrandt, he was one of the 3 people who were
> allowed to touch the microkernel code. That kernel could fit easily in
> a 4K instruction cache and leave room for other processes. They measured
> everything in cache misses, every commit had them thinking about cache
> misses.
>
> I'm definitely a unikernel guy but I had mad respect for QNX, Dan and
> I would talk often about stuff, like how would this work in your world
> and how would it work in my world. The QNX core team was amazing.
>
> Sadly, we lost Dan to brain cancer (I think) in 1998.
> --
> ---
> Larry McVoy lm at mcvoy.com http://www.mcvoy.com/lm
next prev parent reply other threads:[~2020-07-21 2:32 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 18:08 [TUHS] H.J. Lu Bootable Root & Base System disks Norman Wilson
2020-07-17 18:14 ` John Cowan
2020-07-17 18:19 ` Larry McVoy
2020-07-17 19:53 ` [TUHS] Linux is on-topic Warren Toomey
2020-07-17 19:57 ` Larry McVoy
2020-07-17 20:00 ` Adam Thornton
2020-07-17 20:04 ` Larry McVoy
2020-07-17 20:03 ` Dan Cross
2020-07-17 23:31 ` A. P. Garcia
2020-07-19 10:26 ` emanuel stiebler
2020-07-17 20:07 ` Warren Toomey
2020-07-17 20:12 ` Warner Losh
2020-07-17 20:19 ` Clem Cole
2020-07-19 9:54 ` Sergio Pedraja
2020-07-17 20:08 ` Michael Kjörling
2020-07-17 20:55 ` Grant Taylor via TUHS
2020-07-17 21:28 ` Michael Kjörling
2020-07-18 20:22 ` Ed Carp
2020-07-18 20:29 ` Warner Losh
2020-07-19 2:31 ` Gregg Levine
2020-07-19 3:46 ` Wesley Parish
2020-07-19 4:42 ` Grant Taylor via TUHS
2020-07-19 18:01 ` Michael Parson
2020-07-20 8:47 ` [TUHS] A/UX [was Linux is on-topic] arnold
2020-07-20 9:46 ` Arno Griffioen
2020-07-20 16:35 ` Arthur Krewat
2020-07-20 17:44 ` Arno Griffioen
2020-07-20 19:07 ` Rich Morin
2020-07-20 19:45 ` Al Kossow
2020-07-20 19:49 ` Al Kossow
2020-07-24 0:01 ` Chris Hanson
2020-07-20 20:20 ` Ed Carp
2020-07-20 21:02 ` John Cowan
2020-07-20 22:27 ` Ed Carp
2020-07-24 0:04 ` Chris Hanson
2020-07-31 23:02 ` Dave Horsfall
2020-07-31 23:12 ` Richard Salz
2020-08-01 1:36 ` Larry McVoy
2020-08-01 16:08 ` Nemo Nusquam
2020-08-01 17:01 ` Arthur Krewat
2020-08-13 0:00 ` Dave Horsfall
2020-08-13 1:47 ` Larry McVoy
2020-08-13 3:15 ` Grant Taylor via TUHS
2020-08-13 4:02 ` Larry Cashdollar via TUHS
2020-08-31 21:12 ` Dave Horsfall
2020-09-03 14:10 ` Michael Parson
2020-08-13 1:53 ` Nemo Nusquam
2020-08-13 17:14 ` Dan Cross
2020-08-13 17:19 ` Henry Bent
2020-08-13 17:58 ` Warner Losh
2020-08-13 20:04 ` John Cowan
2020-08-13 20:52 ` Dan Cross
2020-08-14 17:31 ` Paul Winalski
2020-08-15 1:24 ` Dave Horsfall
2020-08-18 13:57 ` Derek Fawcus
2020-08-18 14:11 ` John Cowan
2020-08-31 21:20 ` Dave Horsfall
2020-08-13 19:18 ` Adam Thornton
2020-08-13 19:28 ` Warner Losh
2020-08-13 20:15 ` [TUHS] AIX link repost [was " Charles H Sauer
2020-08-13 20:09 ` [TUHS] " Rich
2020-08-13 20:16 ` Larry McVoy
2020-08-13 20:17 ` Dr Iain Maoileoin
2020-08-14 1:04 ` Christopher Browne
2020-08-14 17:18 ` Jim Capp
2020-08-14 17:37 ` Jim Capp
2020-08-14 17:39 ` Jon Steinhart
2020-08-15 0:33 ` Rich
2020-08-15 1:20 ` Larry McVoy
2020-08-15 2:08 ` Dave Horsfall
2020-08-15 2:47 ` Warner Losh
2020-08-15 17:44 ` Paul Winalski
2020-08-15 12:05 ` Thomas Paulsen
2020-08-15 1:33 ` Jon Steinhart
2020-08-15 2:02 ` Dave Horsfall
2020-08-15 2:45 ` Andrew Hume
2020-08-15 16:55 ` William Cheswick
2020-08-15 3:29 ` Larry McVoy
2020-08-15 1:40 ` Gregg Levine
2020-08-13 22:24 ` Grant Taylor via TUHS
2020-07-24 0:02 ` Chris Hanson
2020-07-20 9:48 ` Andrew Warkentin
2020-07-20 11:49 ` Larry McVoy
2020-07-20 14:36 ` Clem Cole
2020-07-20 17:24 ` John Cowan
2020-07-20 22:11 ` Ed Carp
2020-07-21 1:04 ` Larry McVoy
2020-07-22 3:13 ` tytso
2020-07-22 5:40 ` Bakul Shah
2020-07-22 14:16 ` Larry McVoy
2020-07-20 12:32 ` Derrik Walker v2.0
2020-07-20 12:54 ` Andrew Warkentin
2020-07-21 1:50 ` Larry McVoy
2020-07-21 2:30 ` Gregg Levine [this message]
2020-07-22 3:44 ` Jason
2020-07-22 12:23 ` Derrik Walker v2.0
2020-07-20 14:28 ` Clem Cole
2020-07-22 3:50 ` Jason
2020-07-22 4:26 ` Henry Bent
2020-07-24 0:10 ` Chris Hanson
2020-07-20 0:24 ` [TUHS] Linux is on-topic Ed Carp
2020-07-22 3:41 ` Jason
2020-07-22 16:15 ` Michael Parson
2020-07-18 3:34 ` Tomasz Rola
2020-07-18 16:45 ` Christopher Browne
2020-07-19 7:32 ` Lars Brinkhoff
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