Re: [for-next][PATCH 0/5] selftests: ftrace: Tracing updates to allow instance testing

[Namhyung Kim]

Hi Steve,

On Tue, Apr 25, 2017 at 09:24:40AM -0400, Steven Rostedt wrote:
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
> for-next
> 
> Head SHA1: d6322f6cc483bd512efd3360fa76d0286a5b528b
> 
> 
> Steven Rostedt (VMware) (5):
>       selftests: ftrace: Allow some tests to be run in a tracing instance
>       selftests: ftrace: Make func_event_triggers and func_traceonoff_triggers tests do instances
>       selftests: ftrace: Have event tests also run in an tracing instance
>       selftests: ftrace: Have some basic tests run in a tracing instance too
>       selftests: ftrace: Allow some event trigger tests to run in an instance

Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>


But I saw a warning during the below test.  I used the for-next branch
but the commit id was different:

c486bbae781cce337a31cbbbc609f2313ab54542 ("Merge branch
'trace/ftrace/core' into trace/ftrace/next").

Thanks,
Namhyung


[2] Basic test for tracers
[  908.674961] 
[  908.675178] ===============================
[  908.675611] [ ERR: suspicious RCU usage.  ]
[  908.675922] 4.11.0-rc5kvm+ #230 Tainted: G        W      
[  908.675922] -------------------------------
[  908.675922] /home/namhyung/project/linux/include/linux/rcupdate.h:842 rcu_read_lock() used illegally while idle!
[  908.675922] 
[  908.675922] other info that might help us debug this:
[  908.675922] 
[  908.675922] 
[  908.675922] RCU used illegally from idle CPU!
[  908.675922] rcu_scheduler_active = 2, debug_locks = 0
[  908.675922] RCU used illegally from extended quiescent state!
[  908.675922] 2 locks held by swapper/0/0:
[  908.675922]  #0:  (max_trace_lock){......}, at: [<ffffffff81143c33>] check_critical_timing+0xa3/0x150
[  908.675922]  #1:  (rcu_read_lock){......}, at: [<ffffffff8111f9b5>] __is_insn_slot_addr+0x5/0x120
[  908.675922] 
[  908.675922] stack backtrace:
[  908.675922] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W       4.11.0-rc5kvm+ #230
[  908.675922] Call Trace:
[  908.675922]  dump_stack+0x68/0x93
[  908.675922]  lockdep_rcu_suspicious+0xe0/0x100
[  908.675922]  ? start_kernel+0x3b7/0x3c4
[  908.675922]  __is_insn_slot_addr+0xe4/0x120
[  908.675922]  ? start_kernel+0x3b7/0x3c4
[  908.675922]  __kernel_text_address+0x69/0xb0
[  908.675922]  ? start_kernel+0x3b7/0x3c4
[  908.675922]  unwind_get_return_address+0x47/0x60
[  908.675922]  __save_stack_trace+0x83/0xd0
[  908.675922]  save_stack_trace+0x1b/0x20
[  908.675922]  __ftrace_trace_stack+0x22e/0x240
[  908.675922]  __trace_stack+0x10/0x20
[  908.675922]  check_critical_timing+0xe9/0x150
[  908.675922]  ? do_idle+0x88/0x120
[  908.675922]  ? default_idle_call+0x23/0x37
[  908.675922]  ? do_idle+0x88/0x120
[  908.675922]  stop_critical_timings+0xcf/0xe0
[  908.675922]  default_idle_call+0x23/0x37
[  908.675922]  do_idle+0x88/0x120
[  908.675922]  cpu_startup_entry+0x1d/0x20
[  908.675922]  rest_init+0x130/0x140
[  908.675922]  start_kernel+0x3b7/0x3c4
[  908.675922]  x86_64_start_reservations+0x2f/0x31
[  908.675922]  x86_64_start_kernel+0x17d/0x190
[  908.675922]  start_cpu+0x14/0x14
[  908.675922]  ? start_cpu+0x14/0x14
	[PASS]