Hi Paul, This is another warning for the same commit. git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu_tasks.2014.07.28d commit bd14ddc45614b61210fdf0ee4e94152948dd9d5e Author: Paul E. McKenney AuthorDate: Mon Jul 28 12:41:25 2014 -0700 Commit: Paul E. McKenney CommitDate: Mon Jul 28 14:57:56 2014 -0700 rcu: Make RCU-tasks track exiting tasks This commit adds synchronization with exiting tasks, so that RCU-tasks avoids waiting on tasks that no longer exist. Signed-off-by: Paul E. McKenney Conflicts: kernel/rcu/update.c +--------------------------------------------------------------------------+------------+------------+------------------+ | | 4e73c5aafb | bd14ddc456 | v3.16-rc7_072910 | +--------------------------------------------------------------------------+------------+------------+------------------+ | boot_successes | 60 | 0 | 0 | | boot_failures | 0 | 20 | 11 | | INFO:trying_to_register_non-static_key | 0 | 20 | 11 | | BUG:sleeping_function_called_from_invalid_context_at_kernel/rcu/update.c | 0 | 20 | 11 | | INFO:lockdep_is_turned_off | 0 | 20 | 11 | | backtrace:cryptomgr_test | 0 | 20 | 11 | | backtrace:do_group_exit | 0 | 20 | 11 | | backtrace:SyS_exit_group | 0 | 20 | 11 | | backtrace:do_exit | 0 | 19 | | +--------------------------------------------------------------------------+------------+------------+------------------+ [ 0.367474] debug: unmapping init [mem 0xc3cbd000-0xc3feffff] [ 0.368575] apm: BIOS not found. [ 0.369357] cryptomgr_test (19) used greatest stack depth: 7060 bytes left [ 0.369940] INFO: trying to register non-static key. [ 0.370011] the code is fine but needs lockdep annotation. [ 0.370011] turning off the locking correctness validator. [ 0.370011] CPU: 0 PID: 19 Comm: cryptomgr_test Not tainted 3.16.0-rc1-00010-gbd14ddc #10 [ 0.370011] 00000000 00000000 c22abe1c b149e13a c14bb000 c22abe54 b1079298 b1673d18 [ 0.370011] 00000000 c22abe54 b106767f 00000286 00000165 00000000 00000000 c14bb180 [ 0.370011] c14bb180 00000246 00000000 c22abe88 b1079c64 00000000 00000000 00000000 [ 0.370011] Call Trace: [ 0.370011] [] dump_stack+0x48/0x60 [ 0.370011] [] __lock_acquire.isra.28+0x878/0xb20 [ 0.370011] [] ? sched_clock_cpu+0xdf/0x120 [ 0.370011] [] lock_acquire+0x84/0x100 [ 0.370011] [] ? exit_rcu_tasks+0x2f/0x50 [ 0.370011] [] _raw_spin_lock+0x3d/0x70 [ 0.370011] [] ? exit_rcu_tasks+0x2f/0x50 [ 0.370011] [] exit_rcu_tasks+0x2f/0x50 [ 0.370011] [] exit_rcu+0x8/0x10 [ 0.370011] [] do_exit+0x596/0x920 [ 0.370011] [] ? cryptomgr_notify+0x440/0x440 [ 0.370011] [] cryptomgr_test+0x2b/0x40 [ 0.370011] [] kthread+0xb0/0xd0 [ 0.370011] [] ? complete+0x12/0x40 [ 0.370011] [] ret_from_kernel_thread+0x21/0x30 [ 0.370011] [] ? __kthread_parkme+0x60/0x60 [ 0.380893] cryptomgr_test (26) used greatest stack depth: 6316 bytes left [ 0.381613] PCLMULQDQ-NI instructions are not detected. [ 0.382045] The force parameter has not been set to 1. The Iris poweroff handler will not be installed. git bisect start 042abb083e26874a281814b00dfd20149c9beae2 64aa90f26c06e1cb2aacfb98a7d0eccfbd6c1a91 -- git bisect bad 935104624f31f70fd24874e67431838b7af8ed1b # 11:57 0- 20 Merge 'asoc/topic/rockchip' into devel-hourly-2014072910 git bisect good 6eb8c6122aab6e944113d6cada6e579468974251 # 12:01 20+ 0 Merge 'pinctrl/for-next' into devel-hourly-2014072910 git bisect bad 6f6c1629afd346f9897fcaf5b09ccc179be8ef57 # 12:17 0- 8 Merge 'jcmvbkbc-xtensa/xtensa-kc705' into devel-hourly-2014072910 git bisect bad ea97bfad281dec63417068b0c9686492892af6a2 # 12:20 0- 20 Merge 'rcu/rcu_tasks.2014.07.28d' into devel-hourly-2014072910 git bisect good f255aa5d3cb715389362367326aeeb1b45ab8fc3 # 12:24 20+ 0 Merge 'kgene-samsung/for-next' into devel-hourly-2014072910 git bisect good 21ba29459d3e5f129c1e9626098986521b09dab7 # 12:26 20+ 0 Merge 'net/master' into devel-hourly-2014072910 git bisect good 41d8e02382e1e79c17a78c0898bc938531000716 # 12:33 20+ 0 rcutorture: Add torture tests for RCU-tasks git bisect good 4e73c5aafbe9108c83de0f8f5294e6ccad2e29c3 # 12:38 20+ 0 rcu: Add stall-warning checks for RCU-tasks git bisect bad ebc6436166ae583e6db906eb7ffdb1c198921380 # 12:40 0- 20 rcu: Improve RCU-tasks energy efficiency git bisect bad bd14ddc45614b61210fdf0ee4e94152948dd9d5e # 12:44 0- 10 rcu: Make RCU-tasks track exiting tasks # first bad commit: [bd14ddc45614b61210fdf0ee4e94152948dd9d5e] rcu: Make RCU-tasks track exiting tasks git bisect good 4e73c5aafbe9108c83de0f8f5294e6ccad2e29c3 # 12:51 60+ 0 rcu: Add stall-warning checks for RCU-tasks git bisect bad 042abb083e26874a281814b00dfd20149c9beae2 # 12:53 0- 11 0day head guard for 'devel-hourly-2014072910' git bisect good 31dab719fa50cf56d56d3dc25980fecd336f6ca8 # 12:56 60+ 0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 git bisect good e40cff4a7990e5d73eaad0a2f2593fe725e24cdd # 13:10 60+ 0 Add linux-next specific files for 20140728 This script may reproduce the error. ---------------------------------------------------------------------------- #!/bin/bash kernel=$1 initrd=yocto-minimal-i386.cgz wget --no-clobber https://github.com/fengguang/reproduce-kernel-bug/blob/master/initrd/$initrd kvm=( qemu-system-x86_64 -cpu kvm64 -enable-kvm -kernel $kernel -initrd $initrd -m 320 -smp 1 -net nic,vlan=1,model=e1000 -net user,vlan=1 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -serial stdio -display none -monitor null ) append=( hung_task_panic=1 earlyprintk=ttyS0,115200 debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=10 softlockup_panic=1 nmi_watchdog=panic prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal root=/dev/ram0 rw drbd.minor_count=8 ) "${kvm[@]}" --append "${append[*]}" ---------------------------------------------------------------------------- Thanks, Fengguang