Re: 2.6.24-rc7-rt2

From: Steven Rostedt
Date: Thu Jan 17 2008 - 12:26:25 EST



On Thu, 17 Jan 2008, Mariusz Kozlowski wrote:

> Hello,
>
> > > I found this in dmesg:
> > >
> > > BUG: swapper:0 task might have lost a preemption check!
> > > Pid: 0, comm: swapper Not tainted 2.6.24-rc7-rt2 #3
> > > [<c010386b>] show_trace_log_lvl+0x1d/0x3b
> > > [<c01042f3>] show_trace+0x12/0x14
> > > [<c0104a2f>] dump_stack+0x6a/0x70
> > > [<c0115419>] preempt_enable_no_resched+0x5c/0x5e
> >
> > This is really really strange. cpu_idle calls __preempt_enable_no_resched
> > and not preempt_enable_no_resched (notice the prefixed underscores).
> > So I don't know how you got that output. Did you get any strance rejects
> > in applying this patch?
>
> Nope. Your rt patch applied cleanly to vanilla 2.6.24-rc7.
>

OK, do you still get this message? Also I'm assuming this is x86, right?

Could you also do the following.

Go into your kernel build directory.
Start up gdb (I'm hoping that you compiled with DEBUG_INFO)
gdb vmlinux
(gdb) li *0xc0100e35

and show me what you get.

Thanks,

-- Steve

>
> > > [<c0100e35>] cpu_idle+0x6d/0x82
> > > [<c0323b6e>] rest_init+0x66/0x68
> > > [<c043aba6>] start_kernel+0x20c/0x276
> > > [<00000000>] 0x0
> > > =======================
> > > ---------------------------
> > > | preempt count: 00000000 ]
> > > | 0-level deep critical section nesting:
> > > ----------------------------------------
> > >
> > > Box runs fine though.
>
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