Re: pipe/page fault oddness.

From: Dave Jones
Date: Tue Sep 30 2014 - 14:21:17 EST


On Tue, Sep 30, 2014 at 09:46:45AM -0700, Linus Torvalds wrote:
> On Tue, Sep 30, 2014 at 9:40 AM, Dave Jones <davej@xxxxxxxxxx> wrote:
> >
> > ah, echo 0 > tracing_on isn't enough, I had to 0 out set_ftrace_pid too.
> > Never mind. Subsequent traces all looking the same, minus the tracing
> > junk though.
>
> Yeah, looks like that copy_page_to_iter+0x3b3 is always there.
>
> > Is there some way I can figure out what address it's faulting on ?
> > I wonder if that might give some clues.
>
> Could be useful. There's a trace_page_fault_kernel() entry that should
> give it to you, along with error code.

Hm.

page_fault_kernel: address=__per_cpu_end ip=copy_page_to_iter error_code=0x2

over and over..

Dave


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/