Messages in this thread | | | Date | Mon, 20 Apr 2009 15:55:55 -0400 (EDT) | From | Steven Rostedt <> | Subject | Re: [PATCH 0/4] [GIT PULL] tracing: recursion and compile fixes |
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On Mon, 20 Apr 2009, Steven Rostedt wrote:
> > On Mon, 20 Apr 2009, Ingo Molnar wrote: > > Running tests on all trace events: > > Testing all events: <4>Tracing recursion: HC[0]:SC[0]:NMI[0] > > Recursion is wrong :-/ > > > ------------[ cut here ]------------ > > WARNING: at kernel/trace/ring_buffer.c:1510 ring_buffer_lock_reserve+0xf7/0x1ce() > > Hardware name: To Be Filled By O.E.M. > > Pid: 1, comm: swapper Not tainted 2.6.30-rc2-tip-01538-ge8201b9-dirty #37740 > > Call Trace: > > <IRQ> [<ffffffff80268a01>] warn_slowpath+0xcc/0x114 > > [<ffffffff80299ed3>] ? trace_hardirqs_on_caller+0x11d/0x179 > > [<ffffffff80299ba6>] ? mark_held_locks+0x60/0x95 > > [<ffffffff802ca335>] ring_buffer_lock_reserve+0xf7/0x1ce > > [<ffffffff802ceb60>] trace_buffer_lock_reserve+0x34/0x7e > > [<ffffffff810c8f97>] ? do_IRQ+0xf/0xe8 > > [<ffffffff802cf949>] trace_current_buffer_lock_reserve+0x36/0x4c > > [<ffffffff802d9da4>] function_test_events_call+0x7e/0xe2 > > [<ffffffff80216313>] ? ret_from_intr+0x0/0x16 > > [<ffffffff80215616>] ftrace_call+0x5/0x2b > > [<ffffffff8021630e>] ? common_interrupt+0xe/0x13 > > [<ffffffff810c8f9c>] ? do_IRQ+0x14/0xe8 > > The function tracer was called before we updated the hardirq_count :-/ > > I liked the fact that we can detect same level recursion. Perhaps I'll > just make a depth test instead. Have a max of 16? times we can recurse > (should be plenty) and then bug if we hit it? >
The other option is not to trace any interrupt function that is called before "irq_enter". That would mean we would need to add notrace to do_IRQ and friends.
-- Steve
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