I seem to have this bug also. While this is on a production server, I have some flexibility in rebooting it.
I can note a few issues: 1. The kernel bug only happens with Java (tested both open-jdk7 and oracle8) 2. The java processes block and cannot be killed 3. Any process that tries to inspect the java process becomes blocked (e.g. top, ps, ...). an strace of a ps: open("/proc/41126/status", O_RDONLY) = 6 read(6, "Name:\tjava\nState:\tD (disk sleep)"..., 1024) = 870 close(6) = 0 open("/proc/41126/cmdline", O_RDONLY) = 6 read(6, [BLOCKS there] 4. As long as no queries are done on the blocked java processes, everything works (though the load of the machine is apparently high) Tell me what you need done to test this, and I will do it -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1315736 Title: [Dell PowerEdge R720] Machine Check Exception Status in “linux” package in Ubuntu: Incomplete Bug description: Dell PowerEdge 720 on ubuntu 14.04 shows MCE errors on dmesg. Dell support instructed to run DSET and BIOS hardware diagnostics. Neither of the tools showed any errors. Dell support said that if there was a hardware error it would have been shown on Dell logs and the probable reason for the dmesg log is a bug in ubuntu kernel MCE reporting. So, is it that following dmesg is because of a kernel bug in ubuntu 14.04 server? [11562.171040] Please check user daemon is running. [94953.306404] sbridge: HANDLING MCE MEMORY ERROR [94953.306415] CPU 1: Machine Check Exception: 0 Bank 9: 8c00004b000800c0 [94953.306416] TSC 0 ADDR 2dfa0e1000 MISC 90000800080168c PROCESSOR 0:306e4 TIME 1399142359 SOCKET 1 APIC 20 [94953.306422] sbridge: HANDLING MCE MEMORY ERROR [94953.306423] CPU 1: Machine Check Exception: 0 Bank 10: 8c000050000800c1 [94953.306424] TSC 0 ADDR 2dfa0e1000 MISC 90000000000208c PROCESSOR 0:306e4 TIME 1399142359 SOCKET 1 APIC 20 [94953.532217] EDAC MC1: 1 CE memory scrubbing error on CPU_SrcID#1_Channel#0_DIMM#0 (channel:0 slot:0 page:0x2dfa0e1 offset:0x0 grain:32 syndrome:0x0 - area:DRAM err_code:0008:00c0 socket:1 channel_mask:3 rank:0) [94953.532226] EDAC MC1: 1 CE memory scrubbing error on CPU_SrcID#1_Channel#1_DIMM#0 (channel:1 slot:0 page:0x2dfa0e1 offset:0x0 grain:32 syndrome:0x0 - area:DRAM err_code:0008:00c1 socket:1 channel_mask:3 rank:0) --- AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 touko 2 19:15 seq crw-rw---- 1 root audio 116, 33 touko 2 19:15 timer AplayDevices: Error: [Errno 2] No such file or directory ApportVersion: 2.14.1-0ubuntu3 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: Error: [Errno 2] No such file or directory CurrentDmesg: Error: command ['sh', '-c', 'dmesg | comm -13 --nocheck-order /var/log/dmesg -'] failed with exit code 1: comm: /var/log/dmesg: Permission denied dmesg: write failed: Broken pipe DistroRelease: Ubuntu 14.04 InstallationDate: Installed on 2014-02-26 (66 days ago) InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140219) MachineType: Dell Inc. PowerEdge R720 Package: linux (not installed) PciMultimedia: ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic root=UUID=c03eb237-955a-4dee-bba1-deded53df372 ro ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9 RfKill: Error: [Errno 2] No such file or directory Tags: trusty Uname: Linux 3.13.0-24-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: WifiSyslog: _MarkForUpload: True dmi.bios.date: 01/16/2014 dmi.bios.vendor: Dell Inc. dmi.bios.version: 2.2.2 dmi.board.name: 0DCWD1 dmi.board.vendor: Dell Inc. dmi.board.version: A01 dmi.chassis.type: 23 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr2.2.2:bd01/16/2014:svnDellInc.:pnPowerEdgeR720:pvr:rvnDellInc.:rn0DCWD1:rvrA01:cvnDellInc.:ct23:cvr: dmi.product.name: PowerEdge R720 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1315736/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp