2009/6/17 Thomas Gleixner <tglx@xxxxxxxxxxxxx>: > On Tue, 16 Jun 2009, Uwe Kleine-König wrote: >> On Tue, Jun 16, 2009 at 07:59:28AM +0000, Martin Shepherd wrote: >> > Suresh Kumar SHUKLA <suresh.shukla <at> st.com> writes: >> > > // get IRQ descriptor from IRQ, it contains pid >> > > desc = &irq_desc[IRQ_BASIC_TIMER_3_1]; >> > >> > That's a very useful clue. I was thinking that I would have to walk the process >> > tree to find the thread by name. Following up on this clue, it appears as though >> > in kernel 2.6.29.4 I should be able to use desc=irq_to_desc(irq) to look up the >> > IRQ descriptor, then use pid=get_task_pid(desc->thread), to get the PID of the >> > IRQ thread, then use sys_sched_setscheduler(pid,...) to change its priority. >> > I'll try that out in the morning. >> I wouldn't recommend calling sys_sched_setscheduler from kernel space. >> That's the userspace API and you need to pass a __user pointer as third >> argument. >> >> The right way is to do this change from userspace. > > What a nonsense. Care to look at the code ? > > The irq/softirq threads call sys_sched_setscheduler() already to > change their priorities. Yes, I agree with your explanation. > The right way to do this is to have an interface > set_irq_thread_prio(irq, prio) You means that we have to utilize wrapper function using sys_sched_setscheduler() function for PID setting of IRQ thread. It's right? Thks, GeunSik Lim > Thanks, > > tglx -- Regards, GeunSik Lim ( Samsung Electronics ) Blog : http://blog.naver.com/invain/ e-Mail: geunsik.lim@xxxxxxxxxxx leemgs@xxxxxxxxx , leemgs1@xxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ -- 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
