TTY task group scheduling

Jeremy Chadwick freebsd at jdc.parodius.com
Fri Nov 19 14:44:54 UTC 2010


On Fri, Nov 19, 2010 at 02:18:52PM +0000, Vincent Hoffman wrote:
> On 19/11/2010 12:42, Eric Masson wrote:
> > Bruce Cran <bruce at cran.org.uk> writes:
> >
> > Hello,
> >
> >> Google suggests that the work was a GSoC project in 2005 on a pluggable
> >> disk scheduler.
> > It seems that something similar has found its way in DFlyBSD, dsched.
> And indeed to FreeBSD, man gsched. Added sometime round April
> http://svn.freebsd.org/viewvc/base/head/sys/geom/sched/README?view=log

It's been pointed out on the list a couple times, and I've sent mail to
the authors about this, that gsched breaks (very, very badly) things
like sysinstall, and does other strange things like leaves trailing
periods at the end of its ".sched." labels.  This appears to be by
design, but I'm still left thinking "?!"  It's hard to discern technical
innards/workings of GEOM since the documentation is so poor (and reading
the code doesn't help, especially with regards to libgeom).

IMHO, the gsched "stuff", as a "layer", should probably be moved into
the I/O framework by default, with the functionality *disabled* by
default and tunables to adjust it.  That's just how I feel about it.

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |



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