Messages in this thread | | | Date | Tue, 10 Sep 2002 13:55:33 +0200 | From | Stephan von Krawczynski <> | Subject | Re: [PATCH][RFC] per isr in_progress markers |
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On Mon, 9 Sep 2002 21:37:42 +0200 (SAST) Zwane Mwaikambo <zwane@mwaikambo.name> wrote:
> > (Btw, if there is, that would also allow us to notice the "constantly > > screaming PCI interrupt" without help from the low-level isrs) > > As an aside, i just had an idea for another way to improve interrupt > handling latency. Instead of walking through all the isrs in the chain, > we can have an isr flag wether it was the source of the irq, and if so we > stop right there and not walk through the other isrs. Obviously taking > into account that some devices are dumb and have no real way of > determining. > > Zwane
Hello,
a short note on that: this proved to be a particularly bad idea back in the amiga-days. All that happened with this idea (Amiga which has basically only 2 usable interrupts has heavy interrupt sharing) is that every good programmer told the system that it was not the source of the ongoing interrupt - even if it was - because otherwise you lost interrupts in heavy-load environment. Shared interrupts _can_ work well, but you have to do short interrupt-routines and don't mess the thing by over-intelligent (in fact non-atomic) operation.
Regards, Stephan
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