Re: [ANNOUNCE][RFC] PlugSched-6.3.1 for 2.6.16-rc5

Peter Williams wrote:
Al Boldi wrote:
Peter Williams wrote:
Al Boldi wrote:
Control parameters for the scheduler can be read/set via files in:

/sys/cpusched/<scheduler>/

The default values for spa make it really easy to lock up the system.

Which one of the SPA schedulers and under what conditions? I've been
mucking around with these and may have broken something. If so I'd
like to fix it.

spa_no_frills, with a malloc-hog less than timeslice. Setting
promotion_floor to max unlocks the console.

OK, you could also try increasing the promotion interval.

Seems that this will only delay the lock in spa_svr but not inhibit it.

It should be noted that spa_no_frills isn't really expected to behave
very well as it's a pure round robin scheduler.

It's a bare bone scheduler that allows to prioritize procs to the admins
desire, instead of leaving the priority management to the scheduler, which
may be undesirable for some but not all.

It's intended purpose is as a basis for more sophisticated schedulers.

And that's why the same problem exists in the child scheds, i.e. spa_ws,
spa_svr, zaphod, but not spa_ebs.

I've been thinking
about removing it as a bootable scheduler and only making its children
available but I find it useful to compare benchmark and other test
results from it with that from the other schedulers to get an idea of
the extra costs involved.

Thanks!

--
Al

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