On 08/01/2011 04:39 AM, Benjamin Herrenschmidt wrote:
> On Mon, 2011-08-01 at 11:59 +0200, Peter Zijlstra wrote:
>>> Signed-off-by: David Ahern
>>> CC: Benjamin Herrenschmidt
>>> CC: Anton Blanchard
>>
>> Hmm, Paul, didn't you fix something like this early on? Anyway, I've
>> no
>> objections
On Mon, 2011-08-01 at 11:59 +0200, Peter Zijlstra wrote:
> > Signed-off-by: David Ahern
> > CC: Benjamin Herrenschmidt
> > CC: Anton Blanchard
>
> Hmm, Paul, didn't you fix something like this early on? Anyway, I've
> no
> objections since I'm really not familiar enough with the PPC side of
>
On Sat, 2011-07-30 at 14:53 -0600, David Ahern wrote:
> A page fault occurred walking the callchain while creating a perf
> sample for the context-switch event. To handle the page fault the
> mmap_sem is needed, but it is currently held by setup_arg_pages.
> (setup_arg_pages calls shift_arg_pages w
Panic observed on an older kernel when collecting call chains for
the context-switch software event:
[]rb_erase+0x1b4/0x3e8
[]__dequeue_entity+0x50/0xe8
[]set_next_entity+0x178/0x1bc
[]pick_next_task_fair+0xb0/0x118
[]schedule+0x500/0x614
[]rwsem_down_failed_common+0xf0/0x264
[]rwsem_down_r
Hi David,
> > I am hoping someone familiar with PPC can help understand a panic
> > that is generated when capturing callchains with context switch
> > events.
> >
> > Call trace is below. The short of it is that walking the callchain
> > generates a page fault. To handle the page fault the mmap_
