Re: [PATCHv3] tracing - avoid soft lockup in trace_pipe

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Mar 25, 2011 at 11:49:37AM -0400, Steven Rostedt wrote:
> On Fri, 2011-03-25 at 12:05 +0100, Jiri Olsa wrote:
> 
> > right, I'm now able to trigger the issue when running setting the tracing
> > as said in the patch and plus running this in few instacies:
> > 
> > (while [ 1 ]; do find / > /dev/null ; done) &
> 
> That didn't work for me either. But if I run hackbench 50 on the box,
> then the trace does hang while it is running.
> 
> > 
> > It's strange I did not need this last time.. not sure why :)
> > 
> > 
> > anyway, the original reproducer I picked this issue from is ltp suite:
> > http://sourceforge.net/projects/ltp/files/LTP%20Source/ltp-20100131/ltp-full-20100131.tgz/download
> > 
> > and running following test:
> > ltp-full-20101031/testcases/kernel/tracing/ftrace_stress_test/ftrace_stress_test.sh 
> > 
> > reproduces the issue all the time for me, and the patch fixies it.
> > Attaching patch rebased to the current master with changed comment.
> 
> Thanks, I'll queue it up for 2.6.40, as I do not think this is that
> critical of a bug.
great, thanks

jirka