flowtable usable or not
kmacy at freebsd.org
Sat Mar 3 17:22:10 UTC 2012
> Less effort is required to get greater profit without having to mess
> around with things because they fit the generic case as opposed to a
> number of niche cases or provide OS features that a user may or may
> not use.
My initial venting of my frustrations at Doug appears to have turned
an open-ended discussion of FreeBSD's merits as a desktop vs. a server
OS. I don't have the inclination to read every response closely, but I
think that it is generating more heat than light. I have three points
that I would like to make before I attempt to transition this thread
back to its initial purpose:
a) We as a members of the community are collectively responsible for
the state of FreeBSD. Simply disabling features or removing
functionality that doesn't work or doesn't work optimally and / or
filing bug reports but not being able or willing to respond to
feedback requests is in essence a form of neglect. Although we all
have day to day obligations for which the use of FreeBSD is extremely
impractical if not impossible ... any progress, any improvements, any
advancements will only happen because *we* made it happen.
b) There are many features and many changes that are introduced in to
FreeBSD which extend the potential user base which are of no obvious
benefit to many users. Just because one doesn't need a feature and
doesn't hear users crying out for it, doesn't mean that it isn't
c) My grievance was in no way with Doug Barton or ports per se, but
with his response as a representative instance of a behaviour which
bothers me, and, taken over time, is detrimental to the whole.
Back to the initial subject line: "flowtable usable or not"
It is possible to re-structure the routing code to have a smaller
cache footprint / shorter lookup time / and eliminate all locking in
the packet transmit path (ip_output, ip_forward). However, it would
take more time and effort than I have to do so as a recreational
activity. The set of people able to fund such an effort is
non-intersecting with the set of people who would benefit the most
heavily from it. Hence, for the time being, for those who want to be
able to approach anywhere near 1Mpps, much less 10 or 15 times that,
whilst continuing to use the regular stack (i.e. not running netmap)
we are left only with flowtable for bypassing the locking and compute
overhead of per-packet route lookups.
It is beyond debate that under some, if not many, circumstances
flowtable was unusable and perhaps continues to be. Hence, any further
reports of "it was broken so I turned it off, and now my life is
better" should be left unsent. If you, the reader, are willing to
contribute to the testing of changes, provide backtraces from cores
etc. please follow up.
Thank you for your support.
“The real damage is done by those millions who want to 'get by.'
The ordinary men who just want to be left in peace. Those who don’t
want their little lives disturbed by anything bigger than themselves.
Those with no sides and no causes. Those who won’t take measure of
their own strength, for fear of antagonizing their own weakness. Those
who don’t like to make waves—or enemies.
Those for whom freedom, honour, truth, and principles are only
literature. Those who live small, love small, die small. It’s the
reductionist approach to life: if you keep it small, you’ll keep it
under control. If you don’t make any noise, the bogeyman won’t find
But it’s all an illusion, because they die too, those people who
roll up their spirits into tiny little balls so as to be safe. Safe?!
>From what? Life is always on the edge of death; narrow streets lead to
the same place as wide avenues, and a little candle burns itself out
just like a flaming torch does.
I choose my own way to burn.”
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