-- When I'm asked what language is my mother tongue, I simply answer "C". On Fri, 10 Aug 2007, Remy Bohmer wrote: > Hello Darren, Juergen and Ingo, > > Maybe Ingo can look at it, and find a way to implement it more > generic? (In the softirq_info struct we could default set all prios > back to 50, and than from functional point of view there will be no > change for other RT-patch users, but makes Embedded-users life easier. Hi Remy, I'm taking your concern seriously, and we are seeing other areas that it would be nice to set up a different irq priority than the default at boot. Perhaps adding in a new command line interface (We may need to extend the command line size limit). Where one could do irq_priority_map=10-51,21-40,... Where the first number is the irq number followed by the irq priority. We can also do something similar to softirqs. Would something like that satisfy your needs? > > While looking at the IRQ-threads: Notice that setting all IRQ-threads > priorities to 50 with SCHED_FIFO is a bit strange to begin with, > because on a non-RT kernel all IRQ's have different priorities and a > higher prio irq can preempt a lower prio one. (on X86) The current Only if the lower one enabled interrupts ;-) Also that's hardware defined, not user defined. Note that the sofitrqs are not prioritized either. Well, they are by their position in the pending bitmask. But one softirq will not preempt another. > implementation will not preempt another irq-thread due to the same > prios and fifo scheduling. > The implementation I have in this patch follows the original behaviour > more closely, but changing that also could lead to some discussion... > We originally had a special "priority" for each new irq, but found that it really didn't make sense, and we had pressure to make them all the same, and let the user change them. What we need is a way to pass information to the kernel to set a userdefined default. When I get time, I can write up a patch to do something like this. -- Steve - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
