Like Hans, I'm seeing this on 12.04 LTS. linux-image-3.2.0-53-generic- pae seems to enable zram by default, which results in lots of "scheduling while atomic" errors in syslog and occasional lockups (machine still responds to ping, but not ssh, desktop frozen.)
This seems like a pretty critical problem now that it's affecting current LTS.. ** Also affects: linux (Ubuntu) Importance: Undecided Status: New -- 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/1217189 Title: Buffer I/O error on device zram0 (possibly causing complete machine lockup) Status in “linux” package in Ubuntu: New Status in “linux-lts-raring” package in Ubuntu: Confirmed Bug description: This is on linux-image-generic-lts-raring (which I recently upgraded to 3.8.0-29; the problem didn't occur before upgrading AFAIR) I see this junk in my dmesg when creating / formatting a zram swap, and then periodically. Then at some point after heavy swapping incidents, the machine locks up. "Correlation does not imply causation, but it does waggle its eyebrows suggestively" and all that. --- zram: module is from the staging directory, the quality is unknown, you have been warned. zram: num_devices not specified. Using default: 1 zram: Creating 1 devices Adding 1031648k swap on /dev/zram0. Priority:100 extents:1 across:1031648k SS ... Buffer I/O error on device zram0, logical block 257912 [repeated 10 times] ... BUG: scheduling while atomic: rsyslogd/1439/0x00000001 Pid: 1439, comm: rsyslogd Tainted: PF WC O 3.8.0-29-generic #42~precise1-Ubuntu [20931.796635] Pid: 1439, comm: rsyslogd Tainted: PF WC O 3.8.0-29-generic #42~precise1-Ubuntu [20931.796638] Call Trace: [20931.796649] [<c1619449>] __schedule_bug+0x52/0x5e [20931.796653] [<c162c265>] __schedule+0x575/0x5f0 [20931.796660] [<f8439e06>] ? zram_make_request+0xe6/0x100 [zram] [20931.796666] [<c111c38d>] ? release_pages+0x18d/0x1c0 [20931.796669] [<c162c573>] schedule+0x23/0x60 [20931.796673] [<c162d0fd>] rwsem_down_failed_common+0x9d/0xf0 [20931.796677] [<c162d162>] rwsem_down_write_failed+0x12/0x20 [20931.796681] [<c12f809a>] call_rwsem_down_write_failed+0x6/0x8 [20931.796685] [<c162ba44>] ? down_write+0x24/0x30 [20931.796689] [<f8439169>] zram_slot_free_notify+0x29/0x50 [zram] [20931.796693] [<f8439140>] ? zram_stat64_inc+0x30/0x30 [zram] [20931.796700] [<c11460bc>] swap_entry_free+0xdc/0x170 [20931.796703] [<c162d100>] ? rwsem_down_failed_common+0xa0/0xf0 [20931.796708] [<c1146458>] swap_free+0x28/0x40 [20931.796712] [<c1134ba0>] do_swap_page+0x390/0x6f0 [20931.796717] [<c10180f8>] ? sched_clock+0x8/0x10 [20931.796721] [<c11365aa>] handle_pte_fault+0x21a/0x2b0 [20931.796726] [<c10451e1>] ? kmap_atomic_prot+0xf1/0x120 [20931.796730] [<c113746a>] handle_mm_fault+0x1fa/0x2d0 [20931.796735] [<c1630ad0>] __do_page_fault+0x190/0x4f0 [20931.796740] [<c12f63bc>] ? sprintf+0x1c/0x20 [20931.796744] [<c104c132>] ? print_time.part.4+0x82/0xc0 [20931.796748] [<c1630e30>] ? __do_page_fault+0x4f0/0x4f0 [20931.796752] [<c1630e3d>] do_page_fault+0xd/0x10 [20931.796756] [<c162dc17>] error_code+0x67/0x6c [20931.796759] [<c12f8716>] ? __copy_to_user_ll+0x46/0x70 [20931.796763] [<c12f8970>] copy_to_user+0x40/0x60 [20931.796767] [<c104e218>] syslog_print+0xc8/0x210 [20931.796770] [<c104eae6>] do_syslog+0x206/0x390 [20931.796775] [<c106d570>] ? add_wait_queue+0x50/0x50 [20931.796780] [<c11c3680>] ? kmsg_poll+0x50/0x50 [20931.796784] [<c11c36d0>] kmsg_read+0x50/0x60 [20931.796788] [<c11b6584>] proc_reg_read+0x64/0xa0 [20931.796793] [<c116469c>] vfs_read+0x8c/0x160 [20931.796797] [<c10a898d>] ? sys_futex+0xed/0x130 [20931.796801] [<c11b6520>] ? proc_reg_write+0xa0/0xa0 [20931.796805] [<c11647b7>] sys_read+0x47/0x80 ... [30855.181542] Write-error on swap-device (251:0:131064) [43457.030155] Write-error on swap-device (251:0:131064) [43705.090381] Buffer I/O error on device zram0, logical block 16383 Anyway, there's a couple of lkml messages related to this "Buffer I/O error on device zram0", please investigate ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: linux-image-3.8.0-29-generic 3.8.0-29.42~precise1 ProcVersionSignature: Ubuntu 3.8.0-29.42~precise1-generic 3.8.13.5 Uname: Linux 3.8.0-29-generic i686 NonfreeKernelModules: nvidia ApportVersion: 2.0.1-0ubuntu17.4 Architecture: i386 Date: Tue Aug 27 07:33:37 2013 EcryptfsInUse: Yes MarkForUpload: True ProcEnviron: TERM=rxvt LC_COLLATE=C PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: linux-lts-raring UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1217189/+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