FYI, we noticed the following commit: https://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git next commit 9d8f983fe74ecbc411f4824e42e7901df8e7cd85 ("x86/efi: Force EFI reboot to process pending capsules") on test machine: vm-lkp-wsx03-1G: 1 threads qemu-system-x86_64 -enable-kvm -cpu host with 1G memory caused below changes: [ 18.069005] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:97 [ 18.071639] in_atomic(): 0, irqs_disabled(): 1, pid: 7, name: rcu_sched [ 18.073274] CPU: 0 PID: 7 Comm: rcu_sched Tainted: G D 4.6.0-rc4-00028-g9d8f983 #1 [ 18.075685] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 18.078135] ffff88003436f9a0 ffff88003436f9a0 ffffffff8142e53a ffff880034370000 [ 18.080700] 0000000000000061 ffff88003436f9b8 ffffffff810a1048 ffffffff81c8cdd0 [ 18.083325] ffff88003436f9e0 ffffffff810a10d9 ffffffff81f30be0 0000000000000000 [ 18.085940] Call Trace: [ 18.086911] [<ffffffff8142e53a>] dump_stack+0x63/0x89 [ 18.088260] [<ffffffff810a1048>] ___might_sleep+0xd8/0x120 [ 18.089860] [<ffffffff810a10d9>] __might_sleep+0x49/0x80 [ 18.091272] [<ffffffff818f5110>] mutex_lock+0x20/0x50 [ 18.092636] [<ffffffff81771edd>] efi_capsule_pending+0x1d/0x60 [ 18.094272] [<ffffffff8104e749>] native_machine_emergency_restart+0x59/0x280 [ 18.095975] [<ffffffff8104e5d9>] machine_emergency_restart+0x19/0x20 [ 18.097685] [<ffffffff8109d4b8>] emergency_restart+0x18/0x20 [ 18.099303] [<ffffffff81172d6d>] panic+0x1ba/0x217 [ 18.100631] [<ffffffff81030a22>] oops_end+0xc2/0xd0 [ 18.102078] [<ffffffff810654a2>] no_context+0x112/0x380 [ 18.117867] [<ffffffff81065f40>] ? vmalloc_fault+0x340/0x340 [ 18.119315] [<ffffffff8106578c>] __bad_area_nosemaphore+0x7c/0x200 [ 18.120886] [<ffffffff81065915>] ? bad_area_nosemaphore+0x5/0x20 [ 18.122374] [<ffffffff81065924>] bad_area_nosemaphore+0x14/0x20 [ 18.123909] [<ffffffff81065fcb>] __do_page_fault+0x8b/0x4d0 [ 18.125327] [<ffffffff81065f45>] ? __do_page_fault+0x5/0x4d0 [ 18.126832] [<ffffffff810664d3>] trace_do_page_fault+0x43/0x140 [ 18.128385] [<ffffffff8105f6ba>] do_async_page_fault+0x1a/0xa0 [ 18.130434] [<ffffffff818f96f8>] async_page_fault+0x28/0x30 [ 18.131933] [<ffffffff818f61e8>] ? schedule_timeout+0x158/0x2d0 [ 18.133486] [<ffffffff818f9ca8>] ? ftrace_epilogue+0x2/0x2 [ 18.135512] [<ffffffff811475be>] ? ftrace_return_to_handler+0x8e/0x100 [ 18.137597] [<ffffffff818f3060>] ? __schedule+0x8b0/0x8b0 [ 18.139604] [<ffffffff818f9ebd>] return_to_handler+0x15/0x27 [ 18.141556] [<ffffffff818f9ea8>] ? ftrace_graph_caller+0xa8/0xa8 [ 18.143176] [<ffffffff810e3781>] rcu_gp_kthread+0x421/0x970 [ 18.145048] [<ffffffff810e7bc0>] ? trace_raw_output_tick_stop+0x80/0x80 [ 18.146682] [<ffffffff818f9ea8>] ftrace_graph_caller+0xa8/0xa8 [ 18.148193] [<ffffffff810e3360>] ? rcu_process_callbacks+0x610/0x610 [ 18.149766] [<ffffffff8109aef4>] kthread+0xd4/0xf0 [ 18.151185] [<ffffffff818f7682>] ret_from_fork+0x22/0x40 [ 18.152852] [<ffffffff8109ae20>] ? kthread_park+0x60/0x60 FYI, raw QEMU command line is: qemu-system-x86_64 -enable-kvm -cpu host -kernel /pkg/linux/x86_64-rhel/gcc-4.9/9d8f983fe74ecbc411f4824e42e7901df8e7cd85/vmlinuz-4.6.0-rc4-00028-g9d8f983 -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-lkp-wsx03-1G-10/bisect_kernel_selftests-defaults-debian-x86_64-2015-02-07.cgz-x86_64-rhel-9d8f983fe74ecbc411f4824e42e7901df8e7cd85-20160425-37341-1dgwxmg-0.yaml ARCH=x86_64 kconfig=x86_64-rhel branch=linux-devel/devel-spot-201604251010 commit=9d8f983fe74ecbc411f4824e42e7901df8e7cd85 BOOT_IMAGE=/pkg/linux/x86_64-rhel/gcc-4.9/9d8f983fe74ecbc411f4824e42e7901df8e7cd85/vmlinuz-4.6.0-rc4-00028-g9d8f983 max_uptime=3600 RESULT_ROOT=/result/kernel_selftests/defaults/vm-lkp-wsx03-1G/debian-x86_64-2015-02-07.cgz/x86_64-rhel/gcc-4.9/9d8f983fe74ecbc411f4824e42e7901df8e7cd85/0 LKP_SERVER=inn earlyprintk=ttyS0,115200 systemd.log_level=err debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal rw ip=::::vm-lkp-wsx03-1G-10::dhcp' -initrd /fs/sdc1/initrd-vm-lkp-wsx03-1G-10 -m 1024 -smp 1 -device e1000,netdev=net0 -netdev user,id=net0,hostfwd=tcp::23609-:22 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -drive file=/fs/sdc1/disk0-vm-lkp-wsx03-1G-10,media=disk,if=virtio -drive file=/fs/sdc1/disk1-vm-lkp-wsx03-1G-10,media=disk,if=virtio -pidfile /dev/shm/kboot/pid-vm-lkp-wsx03-1G-10 -serial file:/dev/shm/kboot/serial-vm-lkp-wsx03-1G-10 -daemonize -display none -monitor null To reproduce: git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml Thanks, Xiaolong