Greeting, FYI, we noticed the following commit (built with gcc-11): commit: 77c570a1ea85ba4ab135c61a028420a6e9fe77f3 ("blk-cgroup: Remove unnecessary rcu_read_lock/unlock()") https://github.com/ammarfaizi2/linux-block axboe/linux-block/for-next in testcase: boot on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 4G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 14.834675][ T1] ------------[ cut here ]------------ [ 14.835078][ T1] WARNING: CPU: 0 PID: 1 at block/blk-cgroup.c:301 blkg_create+0x39/0x513 [ 14.835690][ T1] Modules linked in: [ 14.835984][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.18.0-rc3-00076-g77c570a1ea85 #1 [ 14.836486][ T1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014 [ 14.836486][ T1] EIP: blkg_create+0x39/0x513 [ 14.836486][ T1] Code: 89 cb 83 ec 0c 83 05 a0 82 8f d9 01 83 15 a4 82 8f d9 00 e8 a5 be 4c ff 85 c0 75 1e 83 05 a8 82 8f d9 01 83 15 ac 82 8f d9 00 < 0f> 0b 83 05 b0 82 8f d9 01 83 15 b4 82 8f d9 00 83 3d 58 9d a6 d8 [ 14.836486][ T1] EAX: 00000000 EBX: f5c26c00 ECX: 00000000 EDX: 00000000 [ 14.836486][ T1] ESI: f5e4c000 EDI: d98f7280 EBP: c12f5e88 ESP: c12f5e70 [ 14.836486][ T1] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010046 [ 14.836486][ T1] CR0: 80050033 CR2: ffd3a000 CR3: 18d38000 CR4: 000406d0 [ 14.836486][ T1] Call Trace: [ 14.836486][ T1] ? _raw_spin_lock_irq+0xba/0xe4 [ 14.836486][ T1] blkcg_init_queue+0xaf/0x20f [ 14.836486][ T1] __alloc_disk_node+0x20c/0x3cc [ 14.836486][ T1] __blk_alloc_disk+0x55/0x97 [ 14.836486][ T1] brd_alloc+0x1d9/0x393 [ 14.836486][ T1] ? debugfs_create_dir+0x20/0x17a [ 14.836486][ T1] brd_init+0x12e/0x1f3 [ 14.836486][ T1] ? ramdisk_size+0x3d/0x3d [ 14.836486][ T1] do_one_initcall+0x6f/0x21e [ 14.836486][ T1] ? lock_is_held+0x19/0x2b [ 14.836486][ T1] ? rcu_read_lock_sched_held+0x4f/0xb7 [ 14.836486][ T1] do_initcalls+0x17f/0x1ec [ 14.836486][ T1] kernel_init_freeable+0x30c/0x3af [ 14.836486][ T1] ? rest_init+0x2f7/0x2f7 [ 14.836486][ T1] kernel_init+0x33/0x2ad [ 14.836486][ T1] ret_from_fork+0x19/0x24 [ 14.836486][ T1] irq event stamp: 212188 [ 14.836486][ T1] hardirqs last enabled at (212187): [] __raw_spin_unlock_irqrestore+0x6e/0xf1 [ 14.836486][ T1] hardirqs last disabled at (212188): [] _raw_spin_lock_irq+0x5f/0xe4 [ 14.836486][ T1] softirqs last enabled at (210872): [] __do_softirq+0x463/0x4ed [ 14.836486][ T1] softirqs last disabled at (210863): [] call_on_stack+0x20/0x3a [ 14.836486][ T1] ---[ end trace 0000000000000000 ]--- To reproduce: # build kernel cd linux cp config-5.18.0-rc3-00076-g77c570a1ea85 .config make HOSTCC=gcc-11 CC=gcc-11 ARCH=i386 olddefconfig prepare modules_prepare bzImage modules make HOSTCC=gcc-11 CC=gcc-11 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 # if come across any failure that blocks the test, # please remove ~/.lkp and /lkp dir to run from a clean state. -- 0-DAY CI Kernel Test Service https://01.org/lkp