Messages in this thread | | | Subject | Re: Preempt & how long it takes to interrupt (was Re: [2.4.17/18pre] VM and swap - it's really unusable) | From | Robert Love <> | Date | 20 Jan 2002 15:22:16 -0500 |
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On Fri, 2002-01-18 at 17:41, Pavel Machek wrote:
> So... how long do you have to stay in interrupt for it to be a bug? > > There's *no* requirement that says "it may not take second to handle > an interrupt". Actually I guess that some nasty conditions (UHCI needs > reset?) may take that long in interrupt. Oh and actually few releases > ago, console switching was done from interrupt and it *did* take 2 > seconds for me. > > If someone assumes interrupts are "short", he has broken code already.
Agreed. Conversely, however, writing code that introduces long interrupt-off periods should be considered a BUG.
In other words, relying on short interrupt-off periods is bad form, but so is writing gross code that rudely keeps them off.
I think we all considered the long off periods in VT switching and fbdev a bug.
Robert Love
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