On Sun, 16 Jan 2005 20:28:24 +0100, Florian Schmidt <mista.tapas@xxxxxxx> wrote: > > > There is a link on the wiki about setting irq priorities, but it seems > > to be broken. How do I set these? and how do I set SCHED_FIFO for an irq > > handler? > > Hmm, "irq priorities" are something different from "irq handler > priorities". The former refers to the priorities on the interrupt > controller. Usually messing with these is not needed, especially on RP > kernels, as the top level irq handler routines are very short. > > What we want to control is the priority of the bottom half irq handler > which is doing the grunt work. For this, the chrt utility from the > schedutils package is useful.. > > chrt -f -p 99 `pidof "IRQ 5"` > > for example, makes the bottom half irq handler for IRQ 5 run SCHED_FIFO > with a priority of 99. Inspect the output of > > cat /proc/interrupts > > to see which irq number corresponds to which device.. > > Use > > chrt -p `pidof "IRQ 5"` > > to inspect the scheduler classes and priorities for irq's.. > This is essentially what Rui's rtirq script does, based on some user input. Florian, I noticed your wiki was locked. It would be great to get some of the up to date info up somewhere (mostly the RT preempt stuff). I was about 1/2 through writing a gentoo how-to when I realized it was much more generic (and most of this stuff isnt in portage anyway). Is there a way to sey up the wiki with a generic lad password? The way the RT stuff (and the kernel in general) has changed and evolved in the last 6 months seems to say we need a doc for this stuff thats really living.
