Re: [PATCH 2/5] tools lib traceevent: handle the '->' operator

[Steven Rostedt]

On Tue, 18 Mar 2014 23:18:24 +0900
Namhyung Kim <namhyung@xxxxxxxxxx> wrote:

> Hi Ramkumar,
> 
> On Tue, Mar 18, 2014 at 11:12 PM, Ramkumar Ramachandra
> <artagnon@xxxxxxxxx> wrote:
> > Hi Namhyung,
> >
> > On Tue, Mar 18, 2014 at 3:58 AM, Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> >> Hmm.. AFAIK we don't support the '->' operator so I think it's an error
> >> in the callsite.  Where do you see the message though?  I couldn't find
> >> it on my setup.
> >>
> >> I'd also like to add following patch to see the location of parse
> >> failure easily.
> >
> > I applied your patch and ran 'perf test'. I get:
> >
> >   Warning: [i915:i915_gem_evict_vm] unknown op '->'
> >
> > So, where should we dig to find this callsite?
> 
> /sys/kernel/debug/tracing/events/i915/i915_gen_evict_vm/format :)
> 

Actually, that's a bug in the kernel. You should *NEVER* redirect from
the ring buffer. There's no guarantee that the data still exists and
this can cause a kernel oops.

-- Steve
--
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/