On Mon, 2003-10-13 at 12:22, David Gillies wrote: > Please excuse this very newbie-ish question, but what > is considered a 'fast' interrupt handler? I know the > definition is an irq handler without an associated > tasklet or BH, but what I mean is, how many clock > cycles should such a handler be allowed to run for? No, a fast interrupt handler is not one without an associated bottom half. A fast interrupt handler is simply one which runs with all interrupts disabled (SA_INTERRUPT). There is no hard and fast rule such as "how many cycles" or whatever. In reality, I would suggest not making your driver run with all interrupts disabled. Only the timer interrupt (which, note, does have a bottom half) should be a fast interrupt these days, if at all possible. In older kernels there was a larger distinction. These days it really doesn't mean anything. Robert Love -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
