Re: [PATCH] tracing/function-return-tracer: set a more human readable output

[Ingo Molnar <mingo@elte.hu>]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> 
> On Wed, 26 Nov 2008, Ingo Molnar wrote:
> 
> > 
> > the regex filter doesnt work well yet when used with the graph tracer:
> > 
> > [ 2994.079079] ------------[ cut here ]------------
> > [ 2994.079079] WARNING: at kernel/trace/ftrace.c:373 ftrace_bug+0x8c/0x1ce()
> > [ 2994.079079] Modules linked in:
> > [ 2994.079079] Pid: 12, comm: kstop/0 Not tainted 2.6.28-rc6-tip #2056
> > [ 2994.079079] Call Trace:
> > [ 2994.079079]  [<c02273dd>] warn_on_slowpath+0x46/0x60
> > [ 2994.079079]  [<c0268308>] ? trace_graph_return+0x89/0xa7
> > [ 2994.079079]  [<c0268308>] ? trace_graph_return+0x89/0xa7
> > [ 2994.079079]  [<c0213e85>] ? ftrace_return_to_handler+0x6b/0x74
> > [ 2994.079079]  [<c0357f66>] ? memcpy+0xe/0x31
> > [ 2994.079079]  [<c02633e6>] ? rb_commit+0x29/0x2d
> > [ 2994.079079]  [<c0264c8b>] ? ring_buffer_unlock_commit+0x15/0x1a
> > [ 2994.079079]  [<c0213ece>] ? ftrace_modify_code+0x21/0xa3
> > [ 2994.079079]  [<c0213e85>] ? ftrace_return_to_handler+0x6b/0x74
> > [ 2994.079079]  [<c026c3ce>] ? probe_kernel_read+0xe/0x5c
> > [ 2994.079079]  [<c0261ec7>] ? trace_selftest_dynamic_test_func+0x3/0xc
> > [ 2994.079079]  [<c0203926>] ? return_to_handler+0xa/0x14
> > [ 2994.079079]  [<c0261ec7>] ? trace_selftest_dynamic_test_func+0x3/0xc
> > [ 2994.079079]  [<c0213ee5>] ? ftrace_modify_code+0x38/0xa3
> > [ 2994.079079]  [<c0261ec7>] ? trace_selftest_dynamic_test_func+0x3/0xc
> > [ 2994.079079]  [<c0262749>] ftrace_bug+0x8c/0x1ce
> > [ 2994.079079]  [<c026299c>] ftrace_replace_code+0x111/0x13d
> > [ 2994.079079]  [<c0253b53>] ? stop_cpu+0x0/0xa5
> > [ 2994.079079]  [<c02629e6>] __ftrace_modify_code+0x1e/0x32
> > [ 2994.079079]  [<c0253bbe>] stop_cpu+0x6b/0xa5
> > [ 2994.079079]  [<c020391c>] return_to_handler+0x0/0x14
> > [ 2994.079079]  [<c020391c>] return_to_handler+0x0/0x14
> > [ 2994.079079]  [<c0237fc1>] ? autoremove_wake_function+0x0/0x35
> > [ 2994.079079]  [<c023584b>] ? worker_thread+0x0/0xc7
> > [ 2994.079079]  [<c0237eba>] kthread+0x40/0x66
> > [ 2994.079079]  [<c0237e7a>] ? kthread+0x0/0x66
> > [ 2994.079079]  [<c02038cb>] kernel_thread_helper+0x7/0x10
> > [ 2994.079079] ---[ end trace bff97d149b80ecde ]---
> > [ 2994.079079] ftrace failed to modify [<c0261ec7>] trace_selftest_dynamic_test_func+0x3/0xc
> > [ 2994.079079]  actual: e8:0c:1a:fa:ff
> > 
> > produced via:
> > 
> >  # cd /debug/tracing/
> >  # cat set_ftrace_filter
> >  # echo schedule > set_ftrace_filter
> >  # cat set_ftrace_filter
> >  cat: set_ftrace_filter: No such device
> 
> This is probably fixed with my patch set.

yeah - but note that the graph-tracer rename came in the way of them. 
Mind redoing your two patches ontop of latest tip/master?

	Ingo