FYI, we noticed the following commit: https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux mm-vmscan-node-lru-v7r15 commit 1e38bcb0550fa03da7035446eecb1bc07ef8c8c8 ("linux-next") on test machine: vm-kbuild-1G: 2 threads qemu-system-x86_64 -enable-kvm -cpu Haswell,+smep,+smap with 1G memory caused below changes: +----------------------------------------------------------------+------------+------------+ | | d313dc67d1 | 1e38bcb055 | +----------------------------------------------------------------+------------+------------+ | boot_successes | 17 | 2 | | boot_failures | 0 | 11 | | INFO:suspicious_RCU_usage | 0 | 11 | | BUG:sleeping_function_called_from_invalid_context_at_mm/slab.h | 0 | 11 | | BUG:scheduling_while_atomic | 0 | 11 | | WARNING:at_kernel/softirq.c:#__local_bh_disable_ip | 0 | 11 | | WARNING:at_kernel/time/timer.c:#del_timer_sync | 0 | 11 | | Kernel_panic-not_syncing:Aiee,killing_interrupt_handler | 0 | 8 | | backtrace:do_sys_open | 0 | 11 | | backtrace:SyS_open | 0 | 11 | | backtrace:SYSC_newstat | 0 | 11 | | backtrace:SyS_newstat | 0 | 11 | | backtrace:SYSC_newlstat | 0 | 10 | | backtrace:SyS_newlstat | 0 | 10 | +----------------------------------------------------------------+------------+------------+ mount.nfs (1100) used greatest stack depth: 11440 bytes left =============================== [ INFO: suspicious RCU usage. ] 4.7.0-rc3-mm1-00203-g1e38bcb #338 Not tainted ------------------------------- include/linux/rcupdate.h:556 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by wrapper/1152: #0: (rcu_read_lock){......}, at: [<ffffffff81228bc8>] rcu_read_lock+0x0/0x68 #1: (rcu_read_lock){......}, at: [<ffffffff8135be1b>] rcu_read_lock+0x0/0x68 stack backtrace: CPU: 1 PID: 1152 Comm: wrapper Not tainted 4.7.0-rc3-mm1-00203-g1e38bcb #338 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 0000000000000000 ffff88005bdafa98 ffffffff8177b8d1 ffff88005c8f0ec0 0000000000000001 ffff88005bdafac8 ffffffff81121540 ffffffff839ff9dd 0000000000000187 0000000000000000 0000000002400040 ffff88005bdafad8 Call Trace: [<ffffffff8177b8d1>] dump_stack+0x82/0xb8 [<ffffffff81121540>] lockdep_rcu_suspicious+0xf7/0x100 [<ffffffff81106d42>] rcu_preempt_sleep_check+0x45/0x47 [<ffffffff81106d60>] ___might_sleep+0x1c/0x1c4 [<ffffffff81106f7d>] __might_sleep+0x75/0x7c [<ffffffff812077e5>] slab_pre_alloc_hook+0x32/0x3f [<ffffffff81209569>] kmem_cache_alloc_trace+0x3d/0x133 [<ffffffff81361a40>] ? nfs_alloc_fattr+0x20/0x37 [<ffffffff81361a40>] nfs_alloc_fattr+0x20/0x37 [<ffffffff81363517>] __nfs_revalidate_inode+0xeb/0x2eb [<ffffffff8135edd7>] nfs_do_access+0x3ec/0x46f [<ffffffff82d41059>] ? generic_lookup_cred+0x1a/0x1c [<ffffffff82d3ffa8>] ? rpcauth_lookupcred+0x61/0x6a [<ffffffff8135ef51>] nfs_permission+0xbe/0x188 [<ffffffff81226b4e>] __inode_permission+0x3e/0xa0 [<ffffffff81226bef>] inode_permission+0x3f/0x41 [<ffffffff812292a8>] link_path_walk+0x47/0x478 [<ffffffff812297f6>] ? path_init+0x11d/0x2a4 [<ffffffff81229f12>] path_openat+0x2ba/0x750 [<ffffffff8109bfd8>] ? kvm_clock_read+0x25/0x2e [<ffffffff8122ba0e>] do_filp_open+0x4d/0xa3 [<ffffffff8110df59>] ? sched_clock_cpu+0x15/0xae [<ffffffff82eda4bd>] ? _raw_spin_unlock+0x27/0x31 [<ffffffff812375fb>] ? __alloc_fd+0x1b2/0x1c4 [<ffffffff8121c55c>] do_sys_open+0x72/0x102 [<ffffffff8121c55c>] ? do_sys_open+0x72/0x102 [<ffffffff8121c60a>] SyS_open+0x1e/0x20 [<ffffffff82edad7c>] entry_SYSCALL_64_fastpath+0x1f/0xbd [<ffffffff8111f86f>] ? trace_hardirqs_off_caller+0x3f/0xab BUG: sleeping function called from invalid context at mm/slab.h:391 in_atomic(): 1, irqs_disabled(): 0, pid: 1152, name: wrapper INFO: lockdep is turned off. CPU: 1 PID: 1152 Comm: wrapper Not tainted 4.7.0-rc3-mm1-00203-g1e38bcb #338 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 0000000000000000 ffff88005bdafad8 ffffffff8177b8d1 ffff88005c8f0ec0 0000000000000480 ffff88005bdafb00 ffffffff81106f01 ffffffff839ff9dd 0000000000000187 0000000000000000 ffff88005bdafb28 ffffffff81106f7d Call Trace: [<ffffffff8177b8d1>] dump_stack+0x82/0xb8 [<ffffffff81106f01>] ___might_sleep+0x1bd/0x1c4 [<ffffffff81106f7d>] __might_sleep+0x75/0x7c [<ffffffff812077e5>] slab_pre_alloc_hook+0x32/0x3f [<ffffffff81209569>] kmem_cache_alloc_trace+0x3d/0x133 [<ffffffff81361a40>] ? nfs_alloc_fattr+0x20/0x37 [<ffffffff81361a40>] nfs_alloc_fattr+0x20/0x37 [<ffffffff81363517>] __nfs_revalidate_inode+0xeb/0x2eb [<ffffffff8135edd7>] nfs_do_access+0x3ec/0x46f [<ffffffff82d41059>] ? generic_lookup_cred+0x1a/0x1c [<ffffffff82d3ffa8>] ? rpcauth_lookupcred+0x61/0x6a [<ffffffff8135ef51>] nfs_permission+0xbe/0x188 [<ffffffff81226b4e>] __inode_permission+0x3e/0xa0 [<ffffffff81226bef>] inode_permission+0x3f/0x41 [<ffffffff812292a8>] link_path_walk+0x47/0x478 [<ffffffff812297f6>] ? path_init+0x11d/0x2a4 [<ffffffff81229f12>] path_openat+0x2ba/0x750 [<ffffffff8109bfd8>] ? kvm_clock_read+0x25/0x2e [<ffffffff8122ba0e>] do_filp_open+0x4d/0xa3 [<ffffffff8110df59>] ? sched_clock_cpu+0x15/0xae [<ffffffff82eda4bd>] ? _raw_spin_unlock+0x27/0x31 [<ffffffff812375fb>] ? __alloc_fd+0x1b2/0x1c4 [<ffffffff8121c55c>] do_sys_open+0x72/0x102 [<ffffffff8121c55c>] ? do_sys_open+0x72/0x102 [<ffffffff8121c60a>] SyS_open+0x1e/0x20 [<ffffffff82edad7c>] entry_SYSCALL_64_fastpath+0x1f/0xbd [<ffffffff8111f86f>] ? trace_hardirqs_off_caller+0x3f/0xab BUG: scheduling while atomic: wrapper/1152/0x00000003 INFO: lockdep is turned off. Modules linked in: CPU: 1 PID: 1152 Comm: wrapper Not tainted 4.7.0-rc3-mm1-00203-g1e38bcb #338 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 0000000000000000 ffff88005bdaf7d8 ffffffff8177b8d1 ffff88005c8f0ec0 0000000000000000 ffff88005bdaf7f0 ffffffff81106466 ffff8800569d9040 ffff88005bdaf850 ffffffff82ed6095 ffff88005bdaf820 00ffffff811229ba Call Trace: [<ffffffff8177b8d1>] dump_stack+0x82/0xb8 [<ffffffff81106466>] __schedule_bug+0x61/0x70 [<ffffffff82ed6095>] __schedule+0x6b/0x76f [<ffffffff82d3e160>] ? trace_event_raw_event_xs_tcp_data_ready+0xd4/0xd4 [<ffffffff82ed6821>] schedule+0x88/0x9d [<ffffffff82d3e184>] rpc_wait_bit_killable+0x24/0xab [<ffffffff82ed6d60>] __wait_on_bit+0x4d/0x7b [<ffffffff82ed6e00>] out_of_line_wait_on_bit+0x72/0x7d [<ffffffff82d3e160>] ? trace_event_raw_event_xs_tcp_data_ready+0xd4/0xd4 [<ffffffff81119687>] ? autoremove_wake_function+0x3a/0x3a [<ffffffff82d359a3>] ? call_transmit_status+0xa4/0xa4 [<ffffffff82d3f222>] __rpc_execute+0x19b/0x411 [<ffffffff811194cd>] ? wake_up_bit+0x25/0x2a [<ffffffff82d3f753>] rpc_execute+0x105/0x16d [<ffffffff82d360f4>] rpc_run_task+0x121/0x12d [<ffffffff81376b67>] nfs4_call_sync_sequence+0x55/0x73 [<ffffffff8137e0b3>] nfs4_call_sync+0x31/0x33 [<ffffffff81380aba>] _nfs4_proc_getattr+0xb6/0xc8 [<ffffffff8177b902>] ? dump_stack+0xb3/0xb8 [<ffffffff81380b15>] nfs4_proc_getattr+0x49/0x172 [<ffffffff81380b15>] ? nfs4_proc_getattr+0x49/0x172 [<ffffffff81361a40>] ? nfs_alloc_fattr+0x20/0x37 [<ffffffff81363553>] __nfs_revalidate_inode+0x127/0x2eb [<ffffffff8135edd7>] nfs_do_access+0x3ec/0x46f [<ffffffff82d41059>] ? generic_lookup_cred+0x1a/0x1c [<ffffffff82d3ffa8>] ? rpcauth_lookupcred+0x61/0x6a [<ffffffff8135ef51>] nfs_permission+0xbe/0x188 [<ffffffff81226b4e>] __inode_permission+0x3e/0xa0 [<ffffffff81226bef>] inode_permission+0x3f/0x41 [<ffffffff812292a8>] link_path_walk+0x47/0x478 [<ffffffff812297f6>] ? path_init+0x11d/0x2a4 [<ffffffff81229f12>] path_openat+0x2ba/0x750 [<ffffffff8109bfd8>] ? kvm_clock_read+0x25/0x2e [<ffffffff8122ba0e>] do_filp_open+0x4d/0xa3 [<ffffffff8110df59>] ? sched_clock_cpu+0x15/0xae [<ffffffff82eda4bd>] ? _raw_spin_unlock+0x27/0x31 [<ffffffff812375fb>] ? __alloc_fd+0x1b2/0x1c4 [<ffffffff8121c55c>] do_sys_open+0x72/0x102 [<ffffffff8121c55c>] ? do_sys_open+0x72/0x102 [<ffffffff8121c60a>] SyS_open+0x1e/0x20 [<ffffffff82edad7c>] entry_SYSCALL_64_fastpath+0x1f/0xbd [<ffffffff8111f86f>] ? trace_hardirqs_off_caller+0x3f/0xab BUG: scheduling while atomic: wrapper/1152/0x7fffffff INFO: lockdep is turned off. Modules linked in: CPU: 1 PID: 1152 Comm: wrapper Tainted: G W 4.7.0-rc3-mm1-00203-g1e38bcb #338 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 0000000000000000 ffff88005bdaf8a8 ffffffff8177b8d1 ffff88005c8f0ec0 0000000000000000 ffff88005bdaf8c0 ffffffff81106466 ffff8800569d9040 ffff88005bdaf920 ffffffff82ed6095 ffff88005bdaf8f0 00ffffff811229ba Call Trace: [<ffffffff8177b8d1>] dump_stack+0x82/0xb8 [<ffffffff81106466>] __schedule_bug+0x61/0x70 [<ffffffff82ed6095>] __schedule+0x6b/0x76f [<ffffffff82d3e160>] ? trace_event_raw_event_xs_tcp_data_ready+0xd4/0xd4 [<ffffffff82ed6821>] schedule+0x88/0x9d [<ffffffff82d3e184>] rpc_wait_bit_killable+0x24/0xab [<ffffffff82ed6d60>] __wait_on_bit+0x4d/0x7b [<ffffffff82ed6e00>] out_of_line_wait_on_bit+0x72/0x7d [<ffffffff82d3e160>] ? trace_event_raw_event_xs_tcp_data_ready+0xd4/0xd4 [<ffffffff81119687>] ? autoremove_wake_function+0x3a/0x3a [<ffffffff82d3d762>] __rpc_wait_for_completion_task+0x2d/0x2f [<ffffffff81376e3c>] rpc_wait_for_completion_task+0xb/0xd [<ffffffff8137827f>] nfs4_run_open_task+0x108/0x135 [<ffffffff81381e46>] nfs4_do_open+0x1f5/0x6e7 [<ffffffff813823bc>] nfs4_atomic_open+0xe/0x1c [<ffffffff8135fd2c>] nfs_atomic_open+0x1ce/0x33c [<ffffffff81227508>] lookup_open+0x2b5/0x4fb [<ffffffff8111eea9>] ? update_fast_ctr+0x1e/0x3e [<ffffffff8111eea9>] ? update_fast_ctr+0x1e/0x3e [<ffffffff8122a014>] path_openat+0x3bc/0x750 [<ffffffff8109bfd8>] ? kvm_clock_read+0x25/0x2e [<ffffffff8122ba0e>] do_filp_open+0x4d/0xa3 [<ffffffff8110df59>] ? sched_clock_cpu+0x15/0xae [<ffffffff82eda4bd>] ? _raw_spin_unlock+0x27/0x31 [<ffffffff812375fb>] ? __alloc_fd+0x1b2/0x1c4 [<ffffffff8121c55c>] do_sys_open+0x72/0x102 [<ffffffff8121c55c>] ? do_sys_open+0x72/0x102 [<ffffffff8121c60a>] SyS_open+0x1e/0x20 [<ffffffff82edad7c>] entry_SYSCALL_64_fastpath+0x1f/0xbd [<ffffffff8111f86f>] ? trace_hardirqs_off_caller+0x3f/0xab BUG: scheduling while atomic: wrapper/1157/0x00000003 INFO: lockdep is turned off. Modules linked in: CPU: 1 PID: 1157 Comm: wrapper Tainted: G W 4.7.0-rc3-mm1-00203-g1e38bcb #338 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 0000000000000000 ffff88005bd477d8 ffffffff8177b8d1 ffff88005bd58e80 0000000000000000 ffff88005bd477f0 ffffffff81106466 ffff8800569d9040 ffff88005bd47850 ffffffff82ed6095 ffff88005bd47820 00ffffff811229ba Call Trace: [<ffffffff8177b8d1>] dump_stack+0x82/0xb8 [<ffffffff81106466>] __schedule_bug+0x61/0x70 [<ffffffff82ed6095>] __schedule+0x6b/0x76f [<ffffffff82d3e160>] ? trace_event_raw_event_xs_tcp_data_ready+0xd4/0xd4 [<ffffffff82ed6821>] schedule+0x88/0x9d [<ffffffff82d3e184>] rpc_wait_bit_killable+0x24/0xab [<ffffffff82ed6d60>] __wait_on_bit+0x4d/0x7b [<ffffffff82ed6e00>] out_of_line_wait_on_bit+0x72/0x7d [<ffffffff82d3e160>] ? trace_event_raw_event_xs_tcp_data_ready+0xd4/0xd4 [<ffffffff81119687>] ? autoremove_wake_function+0x3a/0x3a [<ffffffff82d359a3>] ? call_transmit_status+0xa4/0xa4 [<ffffffff82d3f222>] __rpc_execute+0x19b/0x411 [<ffffffff811194cd>] ? wake_up_bit+0x25/0x2a [<ffffffff82d3f753>] rpc_execute+0x105/0x16d FYI, raw QEMU command line is: qemu-system-x86_64 -enable-kvm -cpu Haswell,+smep,+smap -kernel /pkg/linux/x86_64-allyesdebian/gcc-6/1e38bcb0550fa03da7035446eecb1bc07ef8c8c8/vmlinuz-4.7.0-rc3-mm1-00203-g1e38bcb -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-kbuild-1G-12/bisect_boot-1-debian-x86_64-2015-02-07.cgz-x86_64-allyesdebian-1e38bcb0550fa03da7035446eecb1bc07ef8c8c8-20160618-48145-1qc134s-0.yaml~ ARCH=x86_64 kconfig=x86_64-allyesdebian branch=linux-devel/devel-catchup-201606172211 commit=1e38bcb0550fa03da7035446eecb1bc07ef8c8c8 BOOT_IMAGE=/pkg/linux/x86_64-allyesdebian/gcc-6/1e38bcb0550fa03da7035446eecb1bc07ef8c8c8/vmlinuz-4.7.0-rc3-mm1-00203-g1e38bcb max_uptime=600 RESULT_ROOT=/result/boot/1/vm-kbuild-1G/debian-x86_64-2015-02-07.cgz/x86_64-allyesdebian/gcc-6/1e38bcb0550fa03da7035446eecb1bc07ef8c8c8/0 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-kbuild-1G-12::dhcp' -initrd /fs/sdg1/initrd-vm-kbuild-1G-12 -m 1536 -smp 2 -device e1000,netdev=net0 -netdev user,id=net0,hostfwd=tcp::23011-:22 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -device virtio-scsi-pci,id=scsi0 -drive file=/fs/sdg1/disk0-vm-kbuild-1G-12,if=none,id=hd0,media=disk,aio=native,cache=none -device scsi-hd,bus=scsi0.0,drive=hd0,scsi-id=1,lun=0 -drive file=/fs/sdg1/disk1-vm-kbuild-1G-12,if=none,id=hd1,media=disk,aio=native,cache=none -device scsi-hd,bus=scsi0.0,drive=hd1,scsi-id=1,lun=1 -drive file=/fs/sdg1/disk2-vm-kbuild-1G-12,if=none,id=hd2,media=disk,aio=native,cache=none -device scsi-hd,bus=scsi0.0,drive=hd2,scsi-id=1,lun=2 -drive file=/fs/sdg1/disk3-vm-kbuild-1G-12,if=none,id=hd3,media=disk,aio=native,cache=none -device scsi-hd,bus=scsi0.0,drive=hd3,scsi-id=1,lun=3 -drive file=/fs/sdg1/disk4-vm-kbuild-1G-12,if=none,id=hd4,media=disk,aio=native,cache=none -device scsi-hd,bus=scsi0.0,drive=hd4,scsi-id=1,lun=4 -pidfile /dev/shm/kboot/pid-vm-kbuild-1G-12 -serial file:/dev/shm/kboot/serial-vm-kbuild-1G-12 -daemonize -display none -monitor null Thanks, Kernel Test Robot