Re: [tracing, hang] dumping events gets stuck in synchronise_sched

[Dave Chinner]

On Tue, Aug 17, 2010 at 04:37:44PM +0800, Lai Jiangshan wrote:
> On 08/17/2010 03:37 PM, Dave Chinner wrote:
> > Tracing folks,
> > 
> > I've got a machine stuck with a cpu spinning in a tight loop (the
> > new writeback/sync livelock avoidance code is, well, livelocking),
> > and I was trying to find out what triggered by using the writeback
> > trace events. Unfortunately, I can't dump the trace events because
> > it gets stuck here:
> 
> > 
> > Given that the trace events are there mainly for debugging, this
> > seems like a bit of an oversight - hanging a CPU in a tight loop is
> > not an uncommon event during code development....
> > 
> 
> You can try 'cat trace_pipe', if I did not miss you meaning.

I'll try it, but I'm really after the static event list which is why
I'm using the trace file rather than trace_pipe. I want the history,
not new events as they happen. 

Cheers,

Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx
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