hi, Z qiang,
On Wed, May 08, 2024 at 12:55:25PM +0800, Z qiang wrote:
> >
> >
> >
> > Hello,
> >
> > kernel test robot noticed "BUG:using_smp_processor_id()in_preemptible" on:
> >
> > commit: 4c66bc7cacc08e8abcf5049d2b90bfd800904336 ("rcu/nocb: Use kthread
> > parking instead of ad-hoc implementation")
> > https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
> >
> > [test failed on linux-next/master 9221b2819b8a4196eecf5476d66201be60fbcf29]
> >
> > in testcase: boot
> >
> > compiler: gcc-13
> > test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> >
> > (please refer to attached dmesg/kmsg for entire log/backtrace)
> >
> >
> > +--------------------------------------------------------------+------------+------------+
> > | | 6deb20902f
> > | 4c66bc7cac |
> > +--------------------------------------------------------------+------------+------------+
> > | BUG:using_smp_processor_id()in_preemptible | 0
> > | 12 |
> > +--------------------------------------------------------------+------------+------------+
> >
> >
> > 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 protected]>
> > | Closes: https://lore.kernel.org/oe-lkp/[email protected]
> >
> >
> > [ 4.099901][ T18] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/0/18
> > [ 4.101313][ T18] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.102493][ T18] CPU: 0 PID: 18 Comm: rcuop/0 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.104098][ T18] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.104398][ T18] Call Trace:
> > [ 4.104398][ T18] <TASK>
> > [ 4.104398][ T18] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.104398][ T18] dump_stack (lib/dump_stack.c:124)
> > [ 4.104398][ T18] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.104398][ T18] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.104398][ T18] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.104398][ T18] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
>
>
> Please try the following modifications:
the issue gone with below patch.
Tested-by: kernel test robot <[email protected]>
>
> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> index 340bbefe5f65..b93e40206621 100644
> --- a/kernel/rcu/tree_plugin.h
> +++ b/kernel/rcu/tree_plugin.h
> @@ -28,8 +28,8 @@ static bool rcu_rdp_is_offloaded(struct rcu_data *rdp)
> !(lockdep_is_held(&rcu_state.barrier_mutex) ||
> (IS_ENABLED(CONFIG_HOTPLUG_CPU) && lockdep_is_cpus_held())
> ||
> rcu_lockdep_is_held_nocb(rdp) ||
> - (rdp == this_cpu_ptr(&rcu_data) &&
> - !(IS_ENABLED(CONFIG_PREEMPT_COUNT) && preemptible())) ||
> + (!(IS_ENABLED(CONFIG_PREEMPT_COUNT) && preemptible()) &&
> + rdp == this_cpu_ptr(&rcu_data)) ||
> rcu_current_is_nocb_kthread(rdp)),
> "Unsafe read of RCU_NOCB offloaded state"
> );
>
> Thanks
> Zqiang
>
>
> > [ 4.104398][ T18] ? __this_cpu_preempt_check (lib/smp_processor_id.c:67)
> > [ 4.104398][ T18] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4421
> > (discriminator 16))
> > [ 4.104398][ T18] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.104398][ T18] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.104398][ T18] kthread (kernel/kthread.c:388)
> > [ 4.104398][ T18] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.104398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.104398][ T18] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.104398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.104398][ T18] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.104398][ T18] </TASK>
> > [ 4.106221][ T18] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/0/18
> > [ 4.107796][ T18] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.108547][ T18] CPU: 0 PID: 18 Comm: rcuop/0 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.109667][ T18] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.111064][ T18] Call Trace:
> > [ 4.111064][ T18] <TASK>
> > [ 4.111064][ T18] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.111064][ T18] dump_stack (lib/dump_stack.c:124)
> > [ 4.111064][ T18] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.111064][ T18] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.111064][ T18] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.111064][ T18] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
> > [ 4.111064][ T18] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.111064][ T18] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.111064][ T18] kthread (kernel/kthread.c:388)
> > [ 4.111064][ T18] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.111064][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.111064][ T18] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.111064][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.111064][ T18] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.111064][ T18] </TASK>
> > [ 4.132677][ T1] NMI watchdog: Perf NMI watchdog permanently disabled
> > [ 4.135331][ T18] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/0/18
> > [ 4.137454][ T18] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.137849][ T18] CPU: 0 PID: 18 Comm: rcuop/0 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.139414][ T18] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.141064][ T18] Call Trace:
> > [ 4.141064][ T18] <TASK>
> > [ 4.141064][ T18] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.141064][ T18] dump_stack (lib/dump_stack.c:124)
> > [ 4.141064][ T18] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.141064][ T18] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.141064][ T18] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.141064][ T18] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
> > [ 4.141064][ T18] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.141064][ T18] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.141064][ T18] kthread (kernel/kthread.c:388)
> > [ 4.141064][ T18] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.141064][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.141064][ T18] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.141064][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.141064][ T18] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.141064][ T18] </TASK>
> > [ 4.141391][ T18] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/0/18
> > [ 4.143427][ T18] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.144497][ T18] CPU: 0 PID: 18 Comm: rcuop/0 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.146055][ T18] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.147731][ T18] Call Trace:
> > [ 4.147731][ T18] <TASK>
> > [ 4.147731][ T18] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.147731][ T18] dump_stack (lib/dump_stack.c:124)
> > [ 4.147731][ T18] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.147731][ T18] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.147731][ T18] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.147731][ T18] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
> > [ 4.147731][ T18] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.147731][ T18] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.147731][ T18] kthread (kernel/kthread.c:388)
> > [ 4.147731][ T18] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.147731][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.147731][ T18] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.147731][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.147731][ T18] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.147731][ T18] </TASK>
> > [ 4.148538][ T18] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/0/18
> > [ 4.150537][ T18] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.151144][ T18] CPU: 0 PID: 18 Comm: rcuop/0 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.152635][ T18] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.154398][ T18] Call Trace:
> > [ 4.154398][ T18] <TASK>
> > [ 4.154398][ T18] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.154398][ T18] dump_stack (lib/dump_stack.c:124)
> > [ 4.154398][ T18] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.154398][ T18] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.154398][ T18] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.154398][ T18] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
> > [ 4.154398][ T18] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.154398][ T18] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.154398][ T18] kthread (kernel/kthread.c:388)
> > [ 4.154398][ T18] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.154398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.154398][ T18] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.154398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.154398][ T18] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.154398][ T18] </TASK>
> > [ 4.156100][ T1] smp: Bringing up secondary CPUs ...
> > [ 4.159421][ T18] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/0/18
> > [ 4.161134][ T18] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.162569][ T18] CPU: 0 PID: 18 Comm: rcuop/0 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.164398][ T18] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.164398][ T18] Call Trace:
> > [ 4.164398][ T18] <TASK>
> > [ 4.164398][ T18] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.164398][ T18] dump_stack (lib/dump_stack.c:124)
> > [ 4.164398][ T18] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.164398][ T18] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.164398][ T18] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.164398][ T18] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
> > [ 4.164398][ T18] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.164398][ T18] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.164398][ T18] kthread (kernel/kthread.c:388)
> > [ 4.164398][ T18] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.164398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.164398][ T18] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.164398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.164398][ T18] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.164398][ T18] </TASK>
> > [ 4.168016][ T18] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/0/18
> > [ 4.170139][ T18] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.171170][ T18] CPU: 0 PID: 18 Comm: rcuop/0 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.173242][ T18] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.174398][ T18] Call Trace:
> > [ 4.174398][ T18] <TASK>
> > [ 4.174398][ T18] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.174398][ T18] dump_stack (lib/dump_stack.c:124)
> > [ 4.174398][ T18] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.174398][ T18] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.174398][ T18] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.174398][ T18] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
> > [ 4.174398][ T18] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.174398][ T18] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.174398][ T18] kthread (kernel/kthread.c:388)
> > [ 4.174398][ T18] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.174398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.174398][ T18] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.174398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.174398][ T18] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.174398][ T18] </TASK>
> > [ 4.189949][ T1] smpboot: x86: Booting SMP configuration:
> > [ 4.191158][ T1] .... node #0, CPUs: #1
> > [ 1.668906][ T0] masked ExtINT on CPU#1
> > [ 4.202955][ T29] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/1/29
> > [ 4.204471][ T29] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.205845][ T29] CPU: 0 PID: 29 Comm: rcuop/1 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.207731][ T29] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.207731][ T29] Call Trace:
> > [ 4.207731][ T29] <TASK>
> > [ 4.207731][ T29] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.207731][ T29] dump_stack (lib/dump_stack.c:124)
> > [ 4.207731][ T29] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.207731][ T29] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.207731][ T29] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.207731][ T29] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
> > [ 4.207731][ T29] ? __this_cpu_preempt_check (lib/smp_processor_id.c:67)
> > [ 4.207731][ T29] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4421
> > (discriminator 16))
> > [ 4.207731][ T29] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.207731][ T29] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.207731][ T29] kthread (kernel/kthread.c:388)
> > [ 4.207731][ T29] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.207731][ T29] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.207731][ T29] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.207731][ T29] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.207731][ T29] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.207731][ T29] </TASK>
> > [ 4.207989][ T18] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/0/18
> > [ 4.209997][ T18] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.211188][ T18] CPU: 0 PID: 18 Comm: rcuop/0 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.212898][ T18] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.214398][ T18] Call Trace:
> > [ 4.214398][ T18] <TASK>
> > [ 4.214398][ T18] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.214398][ T18] dump_stack (lib/dump_stack.c:124)
> > [ 4.214398][ T18] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.214398][ T18] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.214398][ T18] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.214398][ T18] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
> > [ 4.214398][ T18] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.214398][ T18] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.214398][ T18] kthread (kernel/kthread.c:388)
> > [ 4.214398][ T18] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.214398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.214398][ T18] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.214398][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.214398][ T18] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.214398][ T18] </TASK>
> > [ 4.215399][ T18] BUG: using smp_processor_id() in preemptible
> > [00000000] code: rcuop/0/18
> > [ 4.217064][ T18] caller is debug_smp_processor_id
> > (lib/smp_processor_id.c:61)
> > [ 4.217772][ T18] CPU: 0 PID: 18 Comm: rcuop/0 Not tainted
> > 6.9.0-rc2-00079-g4c66bc7cacc0 #1
> > [ 4.219363][ T18] Hardware name: QEMU Standard PC (i440FX + PIIX,
> > 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 4.221064][ T18] Call Trace:
> > [ 4.221064][ T18] <TASK>
> > [ 4.221064][ T18] dump_stack_lvl (lib/dump_stack.c:116)
> > [ 4.221064][ T18] dump_stack (lib/dump_stack.c:124)
> > [ 4.221064][ T18] check_preemption_disabled
> > (arch/x86/include/asm/preempt.h:84 (discriminator 15)
> > lib/smp_processor_id.c:53 (discriminator 15))
> > [ 4.221064][ T18] debug_smp_processor_id (lib/smp_processor_id.c:61)
> > [ 4.221064][ T18] rcu_rdp_is_offloaded (kernel/rcu/tree_plugin.h:27
> > (discriminator 1))
> > [ 4.221064][ T18] nocb_cb_wait (kernel/rcu/tree_nocb.h:936 (discriminator
> > 2))
> > [ 4.221064][ T18] rcu_nocb_cb_kthread (kernel/rcu/tree_nocb.h:983
> > (discriminator 1))
> > [ 4.221064][ T18] ? nocb_cb_wait (kernel/rcu/tree_nocb.h:976)
> > [ 4.221064][ T18] kthread (kernel/kthread.c:388)
> > [ 4.221064][ T18] ? kthread (kernel/kthread.c:373 (discriminator 2))
> > [ 4.221064][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.221064][ T18] ret_from_fork (arch/x86/kernel/process.c:153)
> > [ 4.221064][ T18] ? kthread_complete_and_exit (kernel/kthread.c:341)
> > [ 4.221064][ T18] ret_from_fork_asm (arch/x86/entry/entry_64.S:256)
> > [ 4.221064][ T18] </TASK>
> >
> >
> >
> > The kernel config and materials to reproduce are available at:
> > https://download.01.org/0day-ci/archive/20240507/[email protected]
> >
> >
> >
> > --
> > 0-DAY CI Kernel Test Service
> > https://github.com/intel/lkp-tests/wiki
> >
> >
