On arm64 qemu_arm64, juno-r2 and dragonboard-410c while running kselftest ftrace
on stable rc 5.5.1-rc1 to till today 5.5.16-rc2 and 5.6 found this
kernel warning.
[ 386.349099] kselftest: Running tests in ftrace
[ 393.984018]
[ 393.984290] =============================
[ 393.984781] WARNING: suspicious RCU usage
[ 393.988690] 5.6.3-rc2 #1 Not tainted
[ 393.992679] -----------------------------
[ 393.996327] /usr/src/kernel/include/trace/events/ipi.h:36
suspicious rcu_dereference_check() usage!
[ 394.000241]
[ 394.000241] other info that might help us debug this:
[ 394.000241]
[ 394.009094]
[ 394.009094] RCU used illegally from idle CPU!
[ 394.009094] rcu_scheduler_active = 2, debug_locks = 1
[ 394.017084] RCU used illegally from extended quiescent state!
[ 394.028187] 1 lock held by swapper/3/0:
[ 394.033826] #0: ffff80001237b6a8 (max_trace_lock){....}, at:
check_critical_timing+0x7c/0x1a8
[ 394.037480]
[ 394.037480] stack backtrace:
[ 394.046158] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.6.3-rc2 #1
[ 394.050584] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
[ 394.056663] Call trace:
[ 394.063515] dump_backtrace+0x0/0x1e0
[ 394.065686] show_stack+0x24/0x30
[ 394.069505] dump_stack+0xe8/0x150
[ 394.072805] lockdep_rcu_suspicious+0xcc/0x110
[ 394.076106] arch_irq_work_raise+0x208/0x210
[ 394.080533] __irq_work_queue_local+0x5c/0x80
[ 394.084959] irq_work_queue+0x38/0x78
[ 394.089212] __update_max_tr+0x150/0x218
[ 394.092858] update_max_tr_single.part.82+0x98/0x100
[ 394.096851] update_max_tr_single+0x1c/0x28
[ 394.101798] check_critical_timing+0x198/0x1a8
[ 394.105705] stop_critical_timings+0x128/0x148
[ 394.110221] cpuidle_enter_state+0x74/0x4f8
[ 394.114645] cpuidle_enter+0x3c/0x50
[ 394.118726] call_cpuidle+0x44/0x80
[ 394.122542] do_idle+0x22c/0x2d0
[ 394.125755] cpu_startup_entry+0x28/0x48
[ 394.129229] secondary_start_kernel+0x1b4/0x210
metadata:
git branch: linux-5.5.y and linux-5.6.y
git repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
kernel-config:
http://snapshots.linaro.org/openembedded/lkft/lkft/sumo/juno/lkft/linux-stable-rc-5.5/65/config
Full test log,
5.6 test logs,
https://lkft.validation.linaro.org/scheduler/job/1350627#L12612
https://lkft.validation.linaro.org/scheduler/job/1350731#L9509
5.5 test logs,
https://lkft.validation.linaro.org/scheduler/job/1322704#L9777
https://lkft.validation.linaro.org/scheduler/job/1153369#L9745
https://lkft.validation.linaro.org/scheduler/job/1351155#L8982
https://lkft.validation.linaro.org/scheduler/job/1351065#L12349
--
Linaro LKFT
https://lkft.linaro.org
