Greetings, 0day kernel testing robot got the below dmesg and the first bad commit is git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master commit 4788e5b4b2338f85fa42a712a182d8afd65d7c58 Author: Stephane Eranian AuthorDate: Tue Nov 12 17:58:50 2013 +0100 Commit: Ingo Molnar CommitDate: Wed Nov 27 11:16:40 2013 +0100 perf/x86: Add Intel RAPL PMU support This patch adds a new uncore PMU to expose the Intel RAPL energy consumption counters. Up to 3 counters, each counting a particular RAPL event are exposed. The RAPL counters are available on Intel SandyBridge, IvyBridge, Haswell. The server skus add a 3rd counter. The following events are available and exposed in sysfs: - power/energy-cores: power consumption of all cores on socket - power/energy-pkg: power consumption of all cores + LLc cache - power/energy-dram: power consumption of DRAM (servers only) For each event both the unit (Joules) and scale (2^-32 J) is exposed in sysfs for use by perf stat and other tools. The files are: /sys/devices/power/events/energy-*.unit /sys/devices/power/events/energy-*.scale The RAPL PMU is uncore by nature and is implemented such that it only works in system-wide mode. Measuring only one CPU per socket is sufficient. The /sys/devices/power/cpumask file can be used by tools to figure out which CPUs to monitor by default. For instance, on a 2-socket system, 2 CPUs (one on each socket) will be shown. All the counters measure in the same unit (exposed via sysfs). The perf_events API exposes all RAPL counters as 64-bit integers counting in unit of 1/2^32 Joules (about 0.23 nJ). User level tools must convert the counts by multiplying them by 2^-32 to obtain Joules. The reason for this is that the kernel avoids doing floating point math whenever possible because it is expensive (user floating-point state must be saved). The method used avoids kernel floating-point usage. There is no loss of precision. Thanks to PeterZ for suggesting this approach. To convert the raw count in Watt: W = C * 2.3 / (1e10 * time) or ldexp(C, -32). RAPL PMU is a new standalone PMU which registers with the perf_event core subsystem. The PMU type (attr->type) is dynamically allocated and is available from /sys/device/power/type. Sampling is not supported by the RAPL PMU. There is no privilege level filtering either. Signed-off-by: Stephane Eranian Reviewed-by: Maria Dimakopoulou Reviewed-by: Andi Kleen Signed-off-by: Peter Zijlstra Cc: acme@redhat.com Cc: jolsa@redhat.com Cc: zheng.z.yan@intel.com Cc: bp@alien8.de Link: http://lkml.kernel.org/r/1384275531-10892-4-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar +-----------------------------------------------------------+------------+------------+---------------+ | | 410136f5dd | 4788e5b4b2 | next-20140724 | +-----------------------------------------------------------+------------+------------+---------------+ | boot_successes | 1000 | 751 | 78 | | boot_failures | 0 | 149 | 3 | | BUG:unable_to_handle_kernel_NULL_pointer_dereference | 0 | 132 | 2 | | Oops | 0 | 132 | 2 | | EIP_is_at_rapl_pmu_init | 0 | 132 | | | Kernel_panic-not_syncing:Attempted_to_kill_init_exitcode= | 0 | 132 | 2 | | backtrace:rapl_pmu_init | 0 | 132 | | | backtrace:kernel_init_freeable | 0 | 132 | 2 | | BUG:kernel_boot_hang | 0 | 17 | 1 | | EIP_is_at_validate_chain | 0 | 0 | 2 | | backtrace:free_reserved_area | 0 | 0 | 2 | | backtrace:free_init_pages | 0 | 0 | 2 | | backtrace:populate_rootfs | 0 | 0 | 2 | +-----------------------------------------------------------+------------+------------+---------------+ [ 0.613305] PCI: CLS 0 bytes, default 64 [ 0.614699] Unpacking initramfs... [ 0.732188] Freeing initrd memory: 3276K (d3cbd000 - d3ff0000) [ 0.733895] BUG: unable to handle kernel NULL pointer dereference at 00000028 [ 0.735603] IP: [] rapl_pmu_init+0x11e/0x139 [ 0.736012] *pdpt = 0000000000000000 *pde = f000ff53f000ff53 [ 0.736012] Oops: 0000 [#1] PREEMPT [ 0.736012] Modules linked in: [ 0.736012] CPU: 0 PID: 1 Comm: swapper Not tainted 3.12.0-05711-g4788e5b #11 [ 0.736012] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 0.736012] task: d244c020 ti: d244e000 task.ti: d244e000 [ 0.736012] EIP: 0060:[] EFLAGS: 00010202 CPU: 0 [ 0.736012] EIP is at rapl_pmu_init+0x11e/0x139 [ 0.736012] EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: 00000001 [ 0.736012] ESI: c09b1fad EDI: 000000cc EBP: d244ff00 ESP: d244fef0 [ 0.736012] DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0068 [ 0.736012] CR0: 80050033 CR2: 00000028 CR3: 00a16000 CR4: 000406b0 [ 0.736012] Stack: [ 0.736012] c04ddabe 00000000 00000002 00000000 d244ff74 c0200477 c0251b16 d244ff2c [ 0.736012] c025467d d3ff63cb d244ff34 c02410cb d3ff63cb d244ff00 c09aa512 c080d71c [ 0.736012] 000000cc d244ff74 c02412d5 c0829fe0 00000286 c023b6d8 00000246 00060006 [ 0.736012] Call Trace: [ 0.736012] [] ? register_syscore_ops+0x32/0x35 [ 0.736012] [] do_one_initcall+0xdf/0x138 [ 0.736012] [] ? lock_release_holdtime.part.20+0x93/0xf8 [ 0.736012] [] ? trace_hardirqs_on_caller+0xeb/0x1ad [ 0.736012] [] ? parameq+0x13/0x5e [ 0.736012] [] ? repair_env_string+0x12/0x51 [ 0.736012] [] ? parse_args+0x1bf/0x2f8 [ 0.736012] [] ? __usermodehelper_set_disable_depth+0x3e/0x44 [ 0.736012] [] kernel_init_freeable+0xde/0x178 [ 0.736012] [] ? do_early_param+0x78/0x78 [ 0.736012] [] kernel_init+0xb/0xed [ 0.736012] [] ? schedule_tail+0xc/0x3a [ 0.736012] [] ret_from_kernel_thread+0x1b/0x28 [ 0.736012] [] ? rest_init+0xb5/0xb5 [ 0.736012] Code: 99 87 ff 89 5c 24 04 c7 04 24 90 bf 76 c0 e8 dd e9 c9 ff 83 c8 ff eb 28 a1 44 bc a1 c0 f3 0f b8 c0 90 89 44 24 08 a1 80 73 82 c0 <8b> 40 28 89 44 24 04 c7 04 24 d4 bf 76 c0 e8 b2 e9 c9 ff 31 c0 [ 0.736012] EIP: [] rapl_pmu_init+0x11e/0x139 SS:ESP 0068:d244fef0 [ 0.736012] CR2: 0000000000000028 [ 0.736012] ---[ end trace 0a81712c9fb36a0a ]--- [ 0.736012] swapper (1) used greatest stack depth: 5800 bytes left git bisect start v3.14 v3.13 -- git bisect bad 09df7c4c8097ca4a11393b1edd4997d786daad52 # 16:18 0- 3 x86: Remove CONFIG_X86_OOSTORE git bisect bad 15c81026204da897a05424c79263aea861a782cc # 16:24 2- 5 Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect bad a0fa1dd3cdbccec9597fe53b6177a9aa6e20f2f8 # 16:33 0- 15 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect good edde1fb8c41d0db7c8ce17fb32886da2e389b0cc # 17:48 900+ 0 Merge tag 'localmodconfig-v3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-kconfig git bisect good a693c46e14c9fdadbcd68ddfa94a4f72495531a9 # 17:55 900+ 0 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect good 2cc3f16cad1561c6fc551aefff559e53726efc8b # 18:12 900+ 0 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect bad 9326657abe1a83ed4b4f396b923ca1217fd50cba # 18:21 9- 2 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect bad 7bb73553e2490ac6667387ee723e0faa61e9d999 # 18:38 0- 1 tools lib traceevent: Get rid of die() in reparent_op_arg() git bisect bad 3d7c0144491bd8c21d53b43032274a85efdfe434 # 18:41 11- 4 perf tools: Add build and install plugins targets git bisect bad ba1ddf42f3c3af111d3adee277534f73c1ef6a9b # 18:43 0- 15 perf script: Print mmap[2] events also git bisect bad a8b4c7014cadfdacd4e1f4c963128593be6f20de # 18:49 0- 2 perf completion: Rename file to reflect zsh support git bisect bad 4788e5b4b2338f85fa42a712a182d8afd65d7c58 # 18:53 0- 1 perf/x86: Add Intel RAPL PMU support git bisect good c912dae60ae6f659455f239298110adc67a5f3e9 # 19:33 900+ 14 uprobes: Cleanup !CONFIG_UPROBES decls, unexport xol_area git bisect good 09897d78dbc3a544426f2272b5601c62922ccab9 # 19:44 900+ 0 Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core git bisect good 410136f5dd96b6013fe6d1011b523b1c247e1ccb # 19:52 900+ 0 tools/perf/stat: Add event unit and scale support # first bad commit: [4788e5b4b2338f85fa42a712a182d8afd65d7c58] perf/x86: Add Intel RAPL PMU support git bisect good 410136f5dd96b6013fe6d1011b523b1c247e1ccb # 19:56 1000+ 0 tools/perf/stat: Add event unit and scale support git bisect bad 1a58d9909611972fd1c081bb04a9f7dc2571e612 # 19:58 0- 3 Add linux-next specific files for 20140724 git bisect bad 82e13c71bc655b6dc7110da4e164079dadb44892 # 20:07 448- 10 Merge branch 'for-3.16' of git://linux-nfs.org/~bfields/linux git bisect bad 5a7439efd1c5c416f768fc550048ca130cf4bf99 # 20:14 2- 6 Add linux-next specific files for 20140725 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 -enable-kvm -cpu Haswell,+smep,+smap -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