Hi Tejun, 0day kernel testing robot got the below dmesg and the first bad commit is git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-dfl_files commit 53fcf10b90f01b8dbdaa9fd380ebe64a10ffbc78 Author: Tejun Heo AuthorDate: Thu Jul 3 11:18:30 2014 -0400 Commit: Tejun Heo CommitDate: Thu Jul 3 11:18:30 2014 -0400 cgroup: split cgroup_base_files[] into cgroup_{dfl|legacy}_base_files[] Currently cgroup_base_files[] contains the cgroup core interface files for both legacy and default hierarchies with each file tagged with CFTYPE_INSANE and CFTYPE_ONLY_ON_DFL. This is difficult to read. Let's separate it out to two separate tables, cgroup_dfl_base_files[] and cgroup_legacy_base_files[], and use the appropriate one in cgroup_mkdir() depending on the hierarchy type. This makes tagging each file unnecessary. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo +-------------------------------------------------------------------------+------------+------------+ | | 4eff080ef0 | 53fcf10b90 | +-------------------------------------------------------------------------+------------+------------+ | boot_successes | 60 | 0 | | boot_failures | 0 | 20 | | WARNING:CPU:PID:at_kernel/cgroup.c:cgroup_init_cftypes() | 0 | 20 | | WARNING:CPU:PID:at_arch/x86/kernel/cpu/common.c:warn_pre_alternatives() | 0 | 20 | | BUG:unable_to_handle_kernel_NULL_pointer_dereference | 0 | 20 | | Oops | 0 | 20 | | EIP_is_at_strchr | 0 | 20 | | Kernel_panic-not_syncing:Attempted_to_kill_the_idle_task | 0 | 20 | | backtrace:cgroup_init_cftypes | 0 | 20 | | backtrace:warn_slowpath_null | 0 | 20 | | backtrace:cgroup_init | 0 | 20 | | backtrace:register_filesystem | 0 | 20 | +-------------------------------------------------------------------------+------------+------------+ [ 0.020000] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes) [ 0.020000] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes) [ 0.020227] ------------[ cut here ]------------ [ 0.020756] WARNING: CPU: 0 PID: 0 at kernel/cgroup.c:2988 cgroup_init_cftypes+0x7f/0x86() [ 0.021827] CPU: 0 PID: 0 Comm: swapper Not tainted 3.16.0-rc2-00005-g53fcf10 #369 [ 0.022644] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 0.023510] 00000000 00000000 81b97f50 817e52a2 81b97f80 8103257a 81a73029 00000000 [ 0.024469] 00000000 81a79d73 00000bac 8106e0cc 8106e0cc 81bb29d8 81bb271c 00000000 [ 0.025427] 81b97f90 81032626 00000009 00000000 81b97fa4 8106e0cc 00000000 00020800 [ 0.026389] Call Trace: [ 0.026665] [<817e52a2>] dump_stack+0x16/0x18 [ 0.027162] [<8103257a>] warn_slowpath_common+0x6b/0x82 [ 0.027734] [<8106e0cc>] ? cgroup_init_cftypes+0x7f/0x86 [ 0.028322] [<8106e0cc>] ? cgroup_init_cftypes+0x7f/0x86 [ 0.028903] [<81032626>] warn_slowpath_null+0x1d/0x1f [ 0.029467] [<8106e0cc>] cgroup_init_cftypes+0x7f/0x86 [ 0.030015] [<81c8213c>] cgroup_init+0x15/0x1a9 [ 0.030518] [<810f123b>] ? proc_mkdir+0x14/0x16 [ 0.031030] [<81c6eb40>] start_kernel+0x41c/0x453 [ 0.031546] [<81c6e4da>] ? set_init_arg+0x49/0x49 [ 0.032074] [<81c6e2cb>] i386_start_kernel+0x79/0x7d [ 0.032622] ---[ end trace f7c9b96c96ca301f ]--- [ 0.033214] Initializing cgroup subsys perf_event git bisect start 7af305fa6329db0131931fa49d30aeb8ebffd865 4c834452aad01531db949414f94f817a86348d59 -- git bisect bad 15c0370d9a7b84a5be4b4c6eb50b68b3a4c8a054 # 08:55 0- 20 Merge 'bluetooth/master' into devel-lkp-hsx01-i386-201407040014 git bisect good d9f509f8cad2453e734c1deeb876e86d6656cecb # 08:59 20+ 0 Merge 'amirv/for-netdev' into devel-lkp-hsx01-i386-201407040014 git bisect bad 2f1320f7cecbb26ee09814c18f6ace48452fca11 # 09:01 0- 20 Merge 'cgroup/review-dfl_files' into devel-lkp-hsx01-i386-201407040014 git bisect bad 53fcf10b90f01b8dbdaa9fd380ebe64a10ffbc78 # 09:04 0- 10 cgroup: split cgroup_base_files[] into cgroup_{dfl|legacy}_base_files[] git bisect good afbb1b5b595c1a4b1a6f036f220f7b107a504e2d # 09:14 20+ 0 cgroup: make interface file "cgroup.sane_behavior" legacy-only git bisect good 4eff080ef0fc3d5ba30c6b464c877c24f85b5d71 # 09:17 20+ 0 cgroup: clean up sane_behavior handling # first bad commit: [53fcf10b90f01b8dbdaa9fd380ebe64a10ffbc78] cgroup: split cgroup_base_files[] into cgroup_{dfl|legacy}_base_files[] git bisect good 4eff080ef0fc3d5ba30c6b464c877c24f85b5d71 # 09:20 60+ 0 cgroup: clean up sane_behavior handling git bisect bad 7af305fa6329db0131931fa49d30aeb8ebffd865 # 09:20 0- 11 0day head guard for 'devel-lkp-hsx01-i386-201407040014' git bisect good 5170a3b24a9141e2349a3420448743b7c68f2223 # 09:23 60+ 0 Merge branch 'akpm' (patches from Andrew Morton) git bisect good 0e9ce823ad7bc6b85c279223ae6638d47089461e # 09:26 60+ 0 Add linux-next specific files for 20140703 This script may reproduce the error. ----------------------------------------------------------------------------- #!/bin/bash kernel=$1 kvm=( qemu-system-x86_64 -cpu kvm64 -enable-kvm -kernel $kernel -smp 2 -m 256M -net nic,vlan=0,macaddr=00:00:00:00:00:00,model=virtio -net user,vlan=0 -net nic,vlan=1,model=e1000 -net user,vlan=1 -boot order=nc -no-reboot -watchdog i6300esb -serial stdio -display none -monitor null ) append=( debug sched_debug apic=debug ignore_loglevel sysrq_always_enabled panic=10 prompt_ramdisk=0 earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0 vga=normal root=/dev/ram0 rw ) "${kvm[@]}" --append "${append[*]}" ----------------------------------------------------------------------------- Thanks, Jet