Greeting, FYI, we noticed the following commit (built with gcc-10): commit: 5b79c4a1469bcc5793a361ef57d5d2e2393cabcc ("mm/debug_vm_pgtable: introduce struct pgtable_debug_args") https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master in testcase: locktorture version: with following parameters: runtime: 300s test: cpuhotplug test-description: This torture test consists of creating a number of kernel threads which acquire the lock and hold it for specific amount of time, thus simulating different critical region behaviors. test-url: https://www.kernel.org/doc/Documentation/locking/locktorture.txt on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +--------------------------------------------------------------+------------+------------+ | | a9aac8ea55 | 5b79c4a146 | +--------------------------------------------------------------+------------+------------+ | initcall_debug_vm_pgtable_returned_with_preemption_imbalance | 0 | 6 | | WARNING:at_init/main.c:#do_one_initcall | 0 | 6 | | EIP:do_one_initcall | 0 | 6 | | Kernel_panic-not_syncing:No_working_init_found | 0 | 6 | +--------------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 38.527560][ T1] ------------[ cut here ]------------ [ 38.528444][ T1] initcall debug_vm_pgtable+0x0/0x3cd returned with preemption imbalance [ 38.529965][ T1] WARNING: CPU: 0 PID: 1 at init/main.c:1295 do_one_initcall+0x227/0x2c0 [ 38.531240][ T1] Modules linked in: [ 38.531871][ T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 5.14.0-rc2-00027-g5b79c4a1469b #1 a0a7f3ec31aa9416e222f7109d2330341e30c9 4a [ 38.533875][ T1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 [ 38.535237][ T1] EIP: do_one_initcall+0x227/0x2c0 [ 38.536044][ T1] Code: 64 ff 0d 0c 67 ab c3 0f 85 2d fe ff ff e8 69 4a 6a 01 e9 23 fe ff ff 8d 74 26 00 8d 45 b4 50 56 68 5c 2a 06 c3 e8 6d ce 58 0 1 <0f> 0b 83 c4 0c e9 64 fe ff ff 8d b4 26 00 00 00 00 64 a1 5c 14 ab [ 38.538745][ T1] EAX: 00000047 EBX: 00000000 ECX: 00000000 EDX: 00000001 [ 38.539813][ T1] ESI: c39a68f4 EDI: 00000000 EBP: c4d47f74 ESP: c4d47f1c [ 38.540841][ T1] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010296 [ 38.542035][ T1] CR0: 80050033 CR2: b7dcbbf0 CR3: 03ad9000 CR4: 000406d0 [ 38.543178][ T1] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 38.544210][ T1] DR6: fffe0ff0 DR7: 00000400 [ 38.544931][ T1] Call Trace: [ 38.545505][ T1] ? pmd_advanced_tests+0x14d/0x14d [ 38.546318][ T1] ? lock_is_held_type+0xc6/0x120 [ 38.547089][ T1] ? rcu_read_lock_sched_held+0x41/0x80 [ 38.547929][ T1] do_initcalls+0xf9/0x11b [ 38.548631][ T1] kernel_init_freeable+0xc5/0xf4 [ 38.549427][ T1] ? rest_init+0x260/0x260 [ 38.550123][ T1] kernel_init+0x17/0xf0 [ 38.550804][ T1] ret_from_fork+0x1c/0x30 [ 38.551499][ T1] irq event stamp: 16309295 [ 38.552220][ T1] hardirqs last enabled at (16309305): [] console_unlock+0x27e/0x3b0 [ 38.553556][ T1] hardirqs last disabled at (16309312): [] console_unlock+0x305/0x3b0 [ 38.554902][ T1] softirqs last enabled at (16309200): [] __do_softirq+0x2f0/0x4fa [ 38.556235][ T1] softirqs last disabled at (16309091): [] call_on_stack+0x45/0x50 [ 38.557543][ T1] ---[ end trace 0025ffb206fe1364 ]--- To reproduce: # build kernel cd linux cp config-5.14.0-rc2-00027-g5b79c4a1469b .config make HOSTCC=gcc-10 CC=gcc-10 ARCH=i386 olddefconfig prepare modules_prepare bzImage modules make HOSTCC=gcc-10 CC=gcc-10 ARCH=i386 INSTALL_MOD_PATH= modules_install cd find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k -m modules.cgz job-script # job-script is attached in this email --- 0DAY/LKP+ Test Infrastructure Open Source Technology Center https://lists.01.org/hyperkitty/list/lkp@lists.01.org Intel Corporation Thanks, Oliver Sang