Formula One Scheduler (was Re: Help with git)

[Valdis.Kletnieks at vt.edu]

On Fri, 08 Aug 2014 13:28:45 -0700, Arlie Stephens said:
> On Aug 08 2014, Valdis.Kletnieks at vt.edu wrote:
> > There's a big difference between knowing how to change the spark plugs on
> > a VW Beetle, and being able to walk into a Formula One pit and make tuning
> > suggestions that actually help the performance.
> >
> > And yes, there's *that* big a gap between the usual beginner programmer
> > and some parts of the kernel.  In fact, I'll go out on a limb and say that
> > there are more people in this world that really understand Formula One
> > engines than people who really understand the Linux scheduler. :)
>
> Now that's depressing.

There are 11 teams competing in the 2014 Formula One series.  Say 10 engine
jocks on each team - that leaves us 120 or so people who *really* know
the engines. (And that's probably an under-estimate - McLaren's total
engineering staff is around 240 people, so they probably

Looking at next-20140807:

for i in kernel/sched/*.[ch]; do git blame $i; done | cut -f2- -d'(' | awk '{print $1" "$2}' | sort | uniq -c | sort -nr

There's only 235 entries total.

The top 20:

   8922 Peter Zijlstra
   1629 Ingo Molnar
   1483 Paul Turner
   1317 Dario Faggioli
   1282 Linus Torvalds
   1202 Juri Lelli
    999 Frederic Weisbecker
    703 Gregory Haskins
    643 Rik van
    621 Mel Gorman
    612 Paul Gortmaker
    517 Mike Galbraith
    492 Li Zefan
    472 Steven Rostedt
    346 Nicolas Pitre
    338 Thomas Gleixner
    309 Kirill Tkhai
    282 Tejun Heo
    272 Rusty Russell
    210 Suresh Siddha

The cutoff for "less than 40 lines" is at spot #54, and "less than 10 lines" is
at spot #98, after which point the next 137 people have contributed
single-digit amounts of code.  (Lots of well-known names down in that
single-digit club, too - but those numbers smell more like people who have
changed a kernel API and just fixed up the scheduler uses of the API rather
than doing deep understanding of the kernel).

So less than 100 kernel scheduler contributors, to 120 F1 engine designers.

(And yes, I'm glossing over people who have written big chunks of scheduler
code that have since been replaced.  Feel free to dig through git history
and do your own numbers if you want something more accurate :)

So yeah.  Go ahead and be depressed. :)


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