Re: Problems with 2.6.17-rt8

[Bill Huey (hui) <billh@gnuppy.monkey.org>]

On Thu, Aug 03, 2006 at 10:27:41AM -0400, Steven Rostedt wrote:
> The rest was probably caused as a side effect from above.  The above is
> already broken!
> 
> You have NUMA configured too, so this is also something to look at.
> 
> I still wouldn't ignore the first bug message you got:
> 
> ----
> BUG: scheduling while atomic: udev_run_devd/0x00000001/1568
> 
> Call Trace:
>        <ffffffff8045c693>{__schedule+155}
>        <ffffffff8045f156>{_raw_spin_unlock_irqrestore+53}
>        <ffffffff80242241>{task_blocks_on_rt_mutex+518}
>        <ffffffff80252da0>{free_pages_bulk+39}
>        <ffffffff80252da0>{free_pages_bulk+39}
> ...
> ----
> 
> This could also have a side effect that messes things up.
> 
> Unfortunately, right now I'm assigned to other tasks and I cant spend
> much more time on this at the moment.  So hopefully, Ingo, Thomas or
> Bill, or someone else can help you find the reason for this problem.

free_pages_bulk is definitely being called inside of an atomic.
I force this stack trace when the in_atomic() test is true at the
beginning of the function.


[   29.362863] Call Trace:
[   29.367107]        <ffffffff802a82ac>{free_pages_bulk+86}
[   29.373122]        <ffffffff80261726>{_raw_spin_unlock_irqrestore+44}
[   29.380233]        <ffffffff802a8778>{__free_pages_ok+428}
[   29.386336]        <ffffffff8024f101>{free_hot_page+25}
[   29.392165]        <ffffffff8022e298>{__free_pages+41}
[   29.397898]        <ffffffff806b604d>{__free_pages_bootmem+174}
[   29.404457]        <ffffffff806b5266>{free_all_bootmem_core+253}
[   29.411112]        <ffffffff806b5340>{free_all_bootmem_node+9}
[   29.417574]        <ffffffff806b254e>{numa_free_all_bootmem+61}
[   29.424122]        <ffffffff8046e96e>{_etext+0}
[   29.429224]        <ffffffff806b1392>{mem_init+128}
[   29.434691]        <ffffffff806a17ab>{start_kernel+377}
[   29.440520]        <ffffffff806a129b>{_sinittext+667}
[   29.446669] ---------------------------
[   29.450963] | preempt count: 00000001 ]
[   29.455257] | 1-level deep critical section nesting:
[   29.460732] ----------------------------------------
[   29.466212] .. [<ffffffff806a169a>] .... start_kernel+0x68/0x221
[   29.472815] .....[<ffffffff806a129b>] ..   ( <= _sinittext+0x29b/0x2a2)
[   29.480056]

bill