Messages in this thread | | | Date | Wed, 20 Oct 2004 13:58:33 -0400 | From | Timothy Miller <> | Subject | Re: [PATCH 1/3] Separate IRQ-stacks from 4K-stacks option |
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Lee Revell wrote: > On Wed, 2004-10-20 at 11:35, Arjan van de Ven wrote: > >>On Wed, Oct 20, 2004 at 11:46:32AM -0400, Timothy Miller wrote: >> >>>The rules about how long a hard irq would be allowed to run would have >>>to be draconian. >> >>they already are. > > > The IDE I/O completion in hardirq context means that one can run for > almost 3ms. Apparently at OLS it was decided that the target for > desktop responsiveness was 1ms. So this is a real problem.
What is happening that takes 3ms, and why can't it be broken up?
Are you talking here about PIO? Is there a limited amount of time you have to do the PIO before the data goes away? It may be acceptable to just live with PIO being slow, since high-performance systems will all be using DMA anyhow.
> > What exactly do you mean by "draconian"?
In this case, I mean extremely harsh and restrictive. Usually, it means "excessively harsh", but in this case, I mean that in a good way. :)
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