Re: 2.6.33: ftrace triggers soft lockup

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 2010-03-03 at 14:04 +0800, Américo Wang wrote:
> Hi, Steven, Frederic, Ingo,
> 
> I am not sure if this is ftrace's fault, but it is ftrace who triggers
> the soft lockup. On my machine, it is pretty easy, just run:
> 
> echo function_graph > current_tracer
> 
> I found this when 2.6.33-rc7, but forgot to report here. I just tried today's
> Linus tree, it still has this problem.
> 
> Attached are the full soft lockup warnings.
> 
> Below is my related configs:

Actually this is not enough for me. Could you send me the full config,
as well as the full dmesg, not just the dump.

Thanks!

-- Steve

> 
> CONFIG_STACKTRACE_SUPPORT=y
> # CONFIG_RCU_TRACE is not set
> # CONFIG_TREE_RCU_TRACE is not set
> CONFIG_TRACEPOINTS=y
> CONFIG_HAVE_ARCH_TRACEHOOK=y
> # CONFIG_NF_CONNTRACK is not set
> # CONFIG_NETFILTER_XT_TARGET_TRACE is not set
> CONFIG_MOUSE_PS2_TRACKPOINT=y
> CONFIG_TRACE_IRQFLAGS_SUPPORT=y
> CONFIG_TRACE_IRQFLAGS=y
> CONFIG_STACKTRACE=y
> # CONFIG_BACKTRACE_SELF_TEST is not set
> CONFIG_USER_STACKTRACE_SUPPORT=y
> CONFIG_NOP_TRACER=y
> CONFIG_HAVE_FTRACE_NMI_ENTER=y
> CONFIG_HAVE_FUNCTION_TRACER=y
> CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y
> CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST=y
> CONFIG_HAVE_DYNAMIC_FTRACE=y
> CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y
> CONFIG_HAVE_SYSCALL_TRACEPOINTS=y
> CONFIG_FTRACE_NMI_ENTER=y
> CONFIG_EVENT_TRACING=y
> CONFIG_CONTEXT_SWITCH_TRACER=y
> CONFIG_TRACING=y
> CONFIG_GENERIC_TRACER=y
> CONFIG_TRACING_SUPPORT=y
> CONFIG_FTRACE=y
> CONFIG_FUNCTION_TRACER=y
> CONFIG_FUNCTION_GRAPH_TRACER=y
> # CONFIG_IRQSOFF_TRACER is not set
> # CONFIG_SYSPROF_TRACER is not set
> # CONFIG_SCHED_TRACER is not set
> # CONFIG_FTRACE_SYSCALLS is not set
> # CONFIG_BOOT_TRACER is not set
> # CONFIG_KSYM_TRACER is not set
> # CONFIG_STACK_TRACER is not set
> # CONFIG_KMEMTRACE is not set
> # CONFIG_WORKQUEUE_TRACER is not set
> CONFIG_BLK_DEV_IO_TRACE=y
> CONFIG_DYNAMIC_FTRACE=y
> CONFIG_FTRACE_MCOUNT_RECORD=y
> # CONFIG_FTRACE_STARTUP_TEST is not set
> # CONFIG_MMIOTRACE is not set
> CONFIG_SAMPLE_TRACEPOINTS=m
> # CONFIG_SAMPLE_TRACE_EVENTS is not set
> CONFIG_HAVE_MMIOTRACE_SUPPORT=y
> 
> Sorry that I don't have time to look into this. If you need other info,
> just say.
> 
> Thanks!