Re: preempt-timing-2.6.8-rc1

Lee Revell
2004-07-25T05:15:42Z

On Tue, 2004-07-13 at 10:39, William Lee Irwin III wrote:
> On Tue, Jul 13, 2004 at 05:24:32PM +0300, Lenar L?hmus wrote:
> > What I've excluded (happens all the time):
> > 1) 2ms non-preemptible critical section violated 1 ms preempt threshold
> > starting at schedule+0x36/0x480 and ending at do_IRQ+0xec/0x130
> > it's 2ms 98%. This really happens all the time. Bogus?
>
> Wild guess is that you took an IRQ in dec_preempt_count() and that threw
> your results off. Let me know if the patch below helps at all. My guess
> is it'll cause more apparent problems than it solves.

I applied the patch to 2.6.8-rc2 + voluntary-preempt-I4, and am
constantly getting these:

2ms non-preemptible critical section violated 1 ms preempt threshold starting at schedule+0x65/0x5b0 and ending at do_IRQ+0x101/0x170
[<c01066e7>] dump_stack+0x17/0x20
[<c011426e>] dec_preempt_count+0x10e/0x120
[<c0107cb1>] do_IRQ+0x101/0x170
[<c01062a8>] common_interrupt+0x18/0x20
[<c010421d>] cpu_idle+0x2d/0x40
[<c030a782>] start_kernel+0x1a2/0x1f0
[<c010019f>] 0xc010019f
printk: 1 messages suppressed.
2ms non-preemptible critical section violated 1 ms preempt threshold starting at schedule+0x65/0x5b0 and ending at do_IRQ+0x101/0x170
[<c01066e7>] dump_stack+0x17/0x20
[<c011426e>] dec_preempt_count+0x10e/0x120
[<c0107cb1>] do_IRQ+0x101/0x170
[<c01062a8>] common_interrupt+0x18/0x20
[<c010421d>] cpu_idle+0x2d/0x40
[<c030a782>] start_kernel+0x1a2/0x1f0
[<c010019f>] 0xc010019f
printk: 1 messages suppressed.
2ms non-preemptible critical section violated 1 ms preempt threshold starting at schedule+0x65/0x5b0 and ending at do_IRQ+0x101/0x170
[<c01066e7>] dump_stack+0x17/0x20
[<c011426e>] dec_preempt_count+0x10e/0x120
[<c0107cb1>] do_IRQ+0x101/0x170
[<c01062a8>] common_interrupt+0x18/0x20
[<c010421d>] cpu_idle+0x2d/0x40
[<c030a782>] start_kernel+0x1a2/0x1f0
[<c010019f>] 0xc010019f

This seems related to keyboard input; if I keep a key pressed down they
happen regularly.

These are similar to the XRUN traces I get from ALSA, so I think there
is a real problem here.

Lee