Re: [2.4.17/18pre] VM and swap - it's really unusable

yodaiken
2002-01-12T19:38:30Z

On Sat, Jan 12, 2002 at 02:23:00PM -0500, Ed Sweetman wrote:
> hardware to hardware could have a higher priority than normal programs being
> run. That way they're not preempted by simple programs, it would have to
> be purposely preempted by the user.

Priority is currently, and sensibly, by process. A process may run user
code, do sys-calls, or field interrupts both soft and hard. Now do you want to
adjust the priority at every transition?

> Lowering the latency, sure the low latency code probably does nearly as well
> as the preempt patch. that's fine. Shortening the time locks are held by
> better code can help to a certain extent (unless a lot of the kernel code is
> poorly written, which i doubt). at it's present state though, my idea to
> fix the kernel would be to give parts of the kernel where locks are made,

"Fix" what? What is the objective of your fix?

> that shouldn't be broken normally, higher priorities. That way we can
> distinguish between safe locks to preempt at and the ones that can do harm.
> But those people who require their app to be treated special can run it
> with -20 and preempt everything. To me that makes sense. Is there a

So:
get semaphore on slab memory and raise priority
get preempted by "treated special" app that then
does an operation on the slab queues

Is that what you want?

> reason why it doesn't? Besides ethstetics. the only way the ethsetic

It doesn't work? Is that a sufficient reason?

--
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Victor Yodaiken
Finite State Machine Labs: The RTLinux Company.
www.fsmlabs.com www.rtlinux.com