Re: 2.6.17-rc2+ regression -- audio skipping

From: Peter Williams
Date: Mon May 22 2006 - 01:37:40 EST


Mike Galbraith wrote:
On Mon, 2006-05-22 at 13:30 +1000, Peter Williams wrote:
What about the batch tasks? How do you ensure that they don't get starved? Remember they're "batch" tasks not "background" tasks.


Here, batch means background. To make them batch as in only static
priority, I'd just do away with the second array. Batch as background
makes more sense to me, and since it's my ball and my playground... ;-)


In reality, both batch and background are useful distinct concepts. I think of a batch task as one that needs to be treated fairly (in accordance with its nice value) but for which fairness shouldn't be broken to give it a boost as you might for an interactive task or media streamer. I.e. doing useful work but not interactive or a media streamer and the occasional long latency isn't a disaster.

Background tasks are ones where you don't care if they ever get any cpu :-) except as necessary to prevent priority inversion.

In my schedulers I generalize background to "soft cpu rate caps" with a cap of zero being the same as background. I have patches to add both soft and hard cpu rate caps to the standard scheduler but I'm sitting on them until things settle down a bit.

Anyway, schedulers based on single priority arrays (such as staircase) are looking more attractive every day. :-)

Peter
--
Peter Williams pwil3058@xxxxxxxxxxxxxx

"Learning, n. The kind of ignorance distinguishing the studious."
-- Ambrose Bierce
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