Re: linux-next: Tree for Feb 4

Sedat Dilek
2015-02-05T22:16:26Z

On Thu, Feb 5, 2015 at 11:09 PM, Steven Rostedt <rostedt@goodmis.org> wrote:
> On Thu, 5 Feb 2015 22:45:59 +0100
> Sedat Dilek <sedat.dilek@gmail.com> wrote:
>
>> Steve, this was a typo it's called tlb_flush not tlb_flush*ed*:
>
> Heh, yeah, I typed that entire line in by hand. Just be lucky that was
> the only typo ;-)
>
>>
>> # cat /sys/kernel/debug/tracing/events/tlb/tlb_flush/enable
>> 1
>>
>> [ 391.090381] intel_pstate CPU 1 exiting
>> [ 391.104491] smpboot: CPU 1 is now offline
>>
>
> Now, if you disable that (echo 0 to that file), do you still get the
> rcu lockdep splat if you suspend and resume?
>

YES, I get the call-trace again!

# cat /sys/kernel/debug/tracing/events/tlb/tlb_flush/enable
0

# cat /sys/devices/system/cpu/cpu1/online
0

[ 2470.606222] intel_pstate CPU 1 exiting
[ 2470.628153]
[ 2470.628155] ===============================
[ 2470.628156] [ INFO: suspicious RCU usage. ]
[ 2470.628159] 3.19.0-rc7-next-20150204.9-iniza-small #1 Not tainted
[ 2470.628160] -------------------------------
[ 2470.628162] include/trace/events/tlb.h:37 suspicious
rcu_dereference_check() usage!
[ 2470.628163]
[ 2470.628163] other info that might help us debug this:
[ 2470.628163]
[ 2470.628164]
[ 2470.628164] RCU used illegally from offline CPU!
[ 2470.628164] rcu_scheduler_active = 1, debug_locks = 0
[ 2470.628165] no locks held by swapper/1/0.
[ 2470.628166]
[ 2470.628166] stack backtrace:
[ 2470.628169] CPU: 1 PID: 0 Comm: swapper/1 Not tainted
3.19.0-rc7-next-20150204.9-iniza-small #1
[ 2470.628171] Hardware name: SAMSUNG ELECTRONICS CO., LTD.
530U3BI/530U4BI/530U4BH/530U3BI/530U4BI/530U4BH, BIOS 13XK 03/28/2013
[ 2470.628176] 0000000000000001 ffff88011a44fe18 ffffffff817ecf4d
0000000000000011
[ 2470.628179] ffff88011a448290 ffff88011a44fe48 ffffffff810d6b57
ffff8800cc2660c0
[ 2470.628182] 0000000000000001 ffffffff81d35160 0000000000000002
ffff88011a44fe78
[ 2470.628183] Call Trace:
[ 2470.628192] [<ffffffff817ecf4d>] dump_stack+0x4c/0x65
[ 2470.628198] [<ffffffff810d6b57>] lockdep_rcu_suspicious+0xe7/0x120
[ 2470.628203] [<ffffffff810b7459>] idle_task_exit+0x1c9/0x260
[ 2470.628208] [<ffffffff81054c4e>] play_dead_common+0xe/0x50
[ 2470.628211] [<ffffffff81054ca5>] native_play_dead+0x15/0x140
[ 2470.628216] [<ffffffff8102963f>] arch_cpu_idle_dead+0xf/0x20
[ 2470.628219] [<ffffffff810cdbae>] cpu_startup_entry+0x37e/0x580
[ 2470.628222] smpboot: CPU 1 didn't die...
[ 2470.628224] [<ffffffff81053e20>] start_secondary+0x140/0x150

- Sedat -