2 Sep
2021
2 Sep
'21
3:58 a.m.
One of the things I really appreciate about participating in this community
and studying Unix history (and the history of other systems) is that it
gives one firm intellectual ground from which to evaluate where one is
going: without understanding where one is and where one has been, it's
difficult to assert that one isn't going sideways or completely backwards.
Maybe either of those outcomes is appropriate at times (paradigms shift; we
make mistakes; etc) but generally we want to be moving mostly forward.
The danger when immersing ourselves in history, where we must consider and
appreciate the set of problems that created the evolutionary paths leading
to the systems we are studying, is that our thinking can become calcified
in assuming that those systems continue to meet the needs of the problems
of today. It is therefore always important to reevaluate our base
assumptions in light of either disconfirming evidence or (in our specific
case) changing environments.
To that end, I found Timothy Roscoe's (ETH) joint keynote address at
ATC/OSDI'21 particularly compelling. He argues that what we consider the
"operating system" is only controlling a fraction of a modern computer
these days, and that in many ways our models for what we consider "the
computer" are outdated and incomplete, resulting in systems that are
artificially constrained, insecure, and with separate components that do
not consider each other and therefore frequently conflict. Further,
hardware is ossifying around the need to present a system interface that
can be controlled by something like Linux (used as a proxy more generally
for a Unix-like operating system), simultaneously broadening the divide and
making it ever more entrenched.
Another theme in the presentation is that, to the limited extent
the broader systems research community is actually approaching OS topics at
all, it is focusing almost exclusively on Linux in lieu of new, novel
systems; where non-Linux systems are featured (something like 3 accepted
papers between SOSP and OSDI in the last two years out of $n$), the
described systems are largely Linux-like. Here the presentation reminded me
of Rob Pike's "Systems Software Research is Irrelevant" talk (slides of
which are available in various places, though I know of no recording of
that talk).
Roscoe's challenge is that all of this should be seen as both a challenge
and an opportunity for new research into operating systems specifically:
what would it look like to take a holistic approach towards the hardware
when architecting a new system to drive all this hardware? We have new
tools that can make this tractable, so why don't we do it? Part of it is
bias, but part of it is that we've lost sight of the larger picture. My own
question is, have we become entrenched in the world of systems that are
"good enough"?
Things he does NOT mention are system interfaces to userspace software; he
doesn't seem to have any quibbles with, say, the Linux system call
interface, the process model, etc. He's mostly talking about taking into
account the hardware. Also, in fairness, his highlighting a "small" portion
of the system and saying, "that's what the OS drives!" sort of reminds me
of the US voter maps that show vast tracts of largely unpopulated land
colored a certain shade as having voted for a particular candidate, without
normalizing for population (land doesn't vote, people do, though in the US
there is a relationship between how these things impact the overall
election for, say, the presidency).
I'm curious about other peoples' thoughts on the talk and the overall topic?
https://www.youtube.com/watch?v=36myc8wQhLo
- Dan C.