Messages in this thread | | | Date | Fri, 7 Jul 2006 18:36:22 +0200 | From | Haavard Skinnemoen <> | Subject | Re: AVR32 architecture patch against Linux 2.6.18-rc1 available |
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On Fri, 07 Jul 2006 18:08:48 +1000 Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> need_resched() translates to a test_bit, which doesn't have any > barriers, so it could be optimised away completely. And if you're > intending to use preempt, you need to have preemption disabled in the > idle loop.
Actually, preemption seems to be disabled when entering cpu_idle(), but it must be enabled around the call to schedule(). That explains the "scheduling while atomic" storm we saw when enabling CONFIG_PREEMPT anyway.
CONFIG_PREEMPT support is one of the things still missing, btw. I'll implement that next, now that genirq seems to be working.
> Documentation/sched-arch.txt attempts to explain, and something like > arm26's cpu_idle() is a nice, simple example to follow.
I'll do that. Thanks.
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