Re: [patch] preempt-timing-on-2.6.8-rc2-O2

William Lee Irwin III
2004-08-08T02:33:24Z

On Mon, 2004-08-02 at 06:51, Ingo Molnar wrote:
>> Newest patch at:
>> http://redhat.com/~mingo/voluntary-preempt/preempt-timing-on-2.6.8-rc2-O2

On Sat, Aug 07, 2004 at 10:31:06PM -0400, Lee Revell wrote:
> I get a *lot* of these:
> (swapper/0): 996us non-preemptible critical section violated 100 us
> preempt threshold starting at schedule+0x55/0x5a0 and ending at
> do_IRQ+0x110/0x180
> [<c0106717>] dump_stack+0x17/0x20
> [<c0113eec>] dec_preempt_count+0x3c/0x50
> [<c0107a20>] do_IRQ+0x110/0x180
> [<c01062d8>] common_interrupt+0x18/0x20
> [<c0104222>] cpu_idle+0x32/0x50
> [<c030a782>] start_kernel+0x1a2/0x1f0
> [<c010019f>] 0xc010019f
> This has to be a false positive, because if there were really ~1ms
> non-preemptible critical sections all over the place I would be getting
> xruns.

This seems to be 996us spent in do_IRQ() when it interrupts idle tasks.

-- wli