Subject: Re: [PATCH net-next v1] net: openvswitch: decouple flow_table from ovs_mutex

From: kernel test robot <[email-masked]>
Date: Wed, 18 Mar 2026 22:09:05 +0800

Hello,

kernel test robot noticed "WARNING:suspicious_RCU_usage" on:

commit: e556fbe58fe8144bc9e7f0909344b22af53c05ce ("[PATCH net-next v1] net: openvswitch: decouple flow_table from ovs_mutex")
url: https://github.com/intel-lab-lkp/linux/commits/Adrian-Moreno/net-openvswitch-decouple-flow_table-from-ovs_mutex/20260314-152511
base: https://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git 9089c5f3c444ad6e9eb172e9375615ed0b0bc31c
patch link: https://lore.kernel.org/all/[email-masked]/
patch subject: [PATCH net-next v1] net: openvswitch: decouple flow_table from ovs_mutex

in testcase: boot

config: x86_64-randconfig-013-20260317
compiler: clang-20
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 32G

(please refer to attached dmesg/kmsg for entire log/backtrace)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email-masked]>
| Closes: https://lore.kernel.org/oe-lkp/[email-masked]

[   67.815648][   T24] WARNING: suspicious RCU usage
[   67.819156][   T24] 7.0.0-rc3-00655-ge556fbe58fe8 #1 Tainted: G                T
[   67.821304][   T24] -----------------------------
[   67.822695][   T24] net/openvswitch/datapath.c:2666 RCU-list traversed in non-reader section!!
[   67.825209][   T24]
[   67.825209][   T24] other info that might help us debug this:
[   67.825209][   T24]
[   67.828074][   T24]
[   67.828074][   T24] rcu_scheduler_active = 2, debug_locks = 1
[   67.830500][   T24] 3 locks held by kworker/0:2/24:
[   67.831886][   T24]  #0: ffff88810007db40 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works (kernel/workqueue.c:3250)
[   67.835011][   T24]  #1: ffff88810184fd30 ((work_completion)(&(&ovs_net->masks_rebalance)->work)){+.+.}-{0:0}, at: process_scheduled_works (kernel/workqueue.c:3251)
[   67.841040][   T24]  #2: ffffffff96bd5220 (ovs_mutex){+.+.}-{4:4}, at: ovs_dp_masks_rebalance (net/openvswitch/datapath.c:2666)
[   67.843339][   T24]
[   67.843339][   T24] stack backtrace:
[   67.844454][   T24] CPU: 0 UID: 0 PID: 24 Comm: kworker/0:2 Tainted: G                T   7.0.0-rc3-00655-ge556fbe58fe8 #1 PREEMPT(lazy)
[   67.846651][   T24] Tainted: [T]=RANDSTRUCT
[   67.846651][   T24] Workqueue: events ovs_dp_masks_rebalance
[   67.846651][   T24] Call Trace:
[   67.846651][   T24]  <TASK>
[   67.846651][   T24]  dump_stack_lvl (lib/dump_stack.c:123)
[   67.846651][   T24]  lockdep_rcu_suspicious (kernel/locking/lockdep.c:6877)
[   67.846651][   T24]  ovs_dp_masks_rebalance (net/openvswitch/datapath.c:?)
[   67.846651][   T24]  ? process_scheduled_works (kernel/workqueue.c:3251)
[   67.846651][   T24]  process_scheduled_works (kernel/workqueue.c:?)
[   67.846651][   T24]  worker_thread (kernel/workqueue.c:?)
[   67.846651][   T24]  ? _raw_spin_unlock_irqrestore (arch/x86/include/asm/preempt.h:104 kernel/locking/spinlock.c:194)
[   67.846651][   T24]  kthread (kernel/kthread.c:438)
[   67.846651][   T24]  ? worker_attach_to_pool (kernel/workqueue.c:3385)
[   67.846651][   T24]  ? kthread_unuse_mm (kernel/kthread.c:381)
[   67.846651][   T24]  ret_from_fork (arch/x86/kernel/process.c:164)
[   67.846651][   T24]  ? kthread_unuse_mm (kernel/kthread.c:381)
[   67.846651][   T24]  ret_from_fork_asm (arch/x86/entry/entry_64.S:258)
[   67.846651][   T24]  </TASK>

The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260318/[email-masked]

-- 
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https://github.com/intel/lkp-tests/wiki