FYI, we noticed the following commit:
commit: acb04058de49458010c44bb35b849d45113fd668 ("sched/clock: Fix hotplug
crash")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
in testcase: cpu-hotplug
with following parameters:
on test machine: qemu-system-x86_64 -enable-kvm -cpu Nehalem -smp 2 -m 1G
caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
+-------------------------------------+------------+------------+
| | 02cfdc95a0 | acb04058de |
+-------------------------------------+------------+------------+
| boot_successes | 4 | 0 |
| boot_failures | 0 | 4 |
| INFO:suspicious_RCU_usage | 0 | 4 |
| RCU_used_illegally_from_offline_CPU | 0 | 4 |
+-------------------------------------+------------+------------+
[ 30.328035] masked ExtINT on CPU#1
[ 30.328035]
[ 30.328035] ===============================
[ 30.328035] [ INFO: suspicious RCU usage. ]
[ 30.328035] 4.10.0-rc3-00271-gacb0405 #1 Not tainted
[ 30.328035] -------------------------------
[ 30.328035] kernel/workqueue.c:712 sched RCU or wq_pool_mutex should be held!
[ 30.328035]
[ 30.328035] other info that might help us debug this:
[ 30.328035]
[ 30.328035]
[ 30.328035] RCU used illegally from offline CPU!
[ 30.328035] rcu_scheduler_active = 1, debug_locks = 0
[ 30.328035] no locks held by swapper/1/0.
[ 30.328035]
[ 30.328035] stack backtrace:
[ 30.328035] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.10.0-rc3-00271-gacb0405 #1
[ 30.328035] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.9.3-20161025_171302-gandalf 04/01/2014
[ 30.328035] Call Trace:
[ 30.328035] dump_stack+0x86/0xc0
[ 30.328035] lockdep_rcu_suspicious+0xf7/0x100
[ 30.328035] get_work_pool+0x55/0xa6
To reproduce:
git clone
git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
cd lkp-tests
bin/lkp qemu -k <bzImage> job-script # job-script is attached in this
email
Thanks,
Xiaolong