transparent hugepages flaky on arm64 and armhf

[dann frazier]

linux 3.13.0-24.46

transparent hugepages, which are configured on by default in Ubuntu, are flaky on arm64. The most evident system is that go processes reliably hang or crash. This has been observed with both building juju-core with gccgo, and running the resulting juju binaries.

The root cause of this is that get_user_pages_fast is not yet implemented on arm64 (and arm64). Patches are floating around, but haven't landed.

  http://comments.gmane.org/gmane.linux.ports.arm.kernel/299268

We've verified that either applying those patches, or disabling THP via sysfs, prevents the above issues.

At minimum we should change the default boottime sysfs setting for THP to "never" until we can fix this feature properly.

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1309221

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Joseph Salisbury (jsalisbury)]

Being discussed on the kernel team mailing list:
https://lists.ubuntu.com/archives/kernel-team/2014-April/041621.html

[Tim Gardner (timg-tpi)]

UBUNTU: [Config] CONFIG_TRANSPARENT_HUGEPAGE=n for arm64

[Brad Figg (brad-figg)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-trusty' to 'verification-done-trusty'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[dann frazier (dannf)]

dannf@mustang:~$ cat /proc/version
Linux version 3.13.0-26-generic (buildd@magic) (gcc version 4.8.2 (Ubuntu/Linaro 4.8.2-19ubuntu1) ) #48-Ubuntu SMP Wed May 7 23:35:13 UTC 2014

dannf@mustang:~$ juju -h
Juju -- devops distilled
https://juju.ubuntu.com/

Juju provides easy, intelligent service orchestration on top of environments
such as Amazon EC2, HP Cloud, OpenStack, MaaS, or your own local machine.

Basic commands:
  juju init generate boilerplate configuration for juju environments
  juju bootstrap start up an environment from scratch

  juju deploy deploy a new service
  juju add-relation add a relation between two services
  juju expose expose a service

  juju help bootstrap more help on e.g. bootstrap command
  juju help commands list all commands
  juju help glossary glossary of terms
  juju help topics list all help topics

Provider information:
  juju help azure-provider use on Windows Azure
  juju help ec2-provider use on Amazon EC2
  juju help hpcloud-provider use on HP Cloud
  juju help local-provider use on this computer
  juju help openstack-provider use on OpenStack

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.13.0-27.50

---------------
linux (3.13.0-27.50) trusty; urgency=low

  [ Brad Figg ]

  * Revert "rtlwifi: Set the link state"

linux (3.13.0-27.49) trusty; urgency=low

  [ Brad Figg ]

  * Revert "SAUCE: (no-up) HID: rmi: do not stop the device at the end of
    probe"
  * Revert "SAUCE: (no-up) HID: rmi: introduce RMI driver for Synaptics
    touchpads"
  * Revert "[Config] CONFIG_HID_RMI=m"

linux (3.13.0-26.48) trusty; urgency=low

  [ Benjamin Tissoires ]

  * SAUCE: (no-up) HID: rmi: introduce RMI driver for Synaptics touchpads
    - LP: #1305522
  * SAUCE: (no-up) HID: rmi: do not stop the device at the end of probe
    - LP: #1305522

  [ Kamal Mostafa ]

  * Merged back Ubuntu-3.13.0-24.47 security release
  * Revert "n_tty: Fix n_tty_write crash when echoing in raw mode"
    - LP: #1314762
  * Release Tracking Bug
    - LP: #1316835

  [ Tim Gardner ]

  * [Config] CONFIG_HID_RMI=m
    - LP: #1305522
  * [Config] CONFIG_CRYPTO_DEV_NX=n for ppc64el
    - LP: #1314625
  * [Config] CONFIG_ZSWAP=y
    - LP: #1315203
  * Add rpcsec_gss_krb5 to generic inclusion list
    - LP: #769527

  [ Upstream Kernel Changes ]

  * HID: hidraw: make comment more accurate and nicer
    - LP: #1305522
  * HID: remove hid_get_raw_report in struct hid_device
    - LP: #1305522
  * HID: i2c-hid: implement ll_driver transport-layer callbacks
    - LP: #1305522
  * HID: add inliners for ll_driver transport-layer callbacks
    - LP: #1305522
  * HID: Add transport-driver callbacks to the hid_ll_driver struct
    - LP: #1305522
  * drm/nouveau: fail runtime pm properly.
    - LP: #1313986
  * drm/nouveau: don't suspend/resume display on runtime s/r
    - LP: #1313986
  * n_tty: Fix n_tty_write crash when echoing in raw mode
    - LP: #1314762
    - CVE-2014-0196
  * floppy: ignore kernel-only members in FDRAWCMD ioctl input
    - LP: #1316729
    - CVE-2014-1737
  * floppy: don't write kernel-only members to FDRAWCMD ioctl output
    - LP: #1316735
    - CVE-2014-1738

linux (3.13.0-25.47) trusty; urgency=low

  [ Joseph Salisbury ]

  * Release Tracking Bug
    - LP: #1313868

  [ Adam Lee ]

  * [Config] CONFIG_RTL8723BE=m, CONFIG_RTL8723_COMMON=m
    - LP: #1240940

  [ Alex Hung ]

  * SAUCE: (no-up) dell-led: add mic mute led interface
    - LP: #1308297

  [ Andy Whitcroft ]

  * SAUCE: (no-up) powerpc: Increase COMMAND_LINE_SIZE to 2048 from 512.
    - LP: #1306677

  [ Ben Collins ]

  * [Config] Disable PAMU on Freescale kernels
    - LP: #1311738

  [ Tim Gardner ]

  * Revert "SAUCE: x86, hyperv: bypass the timer_irq_works() check"
    - LP: #1311683
  * SAUCE: (no-up) ALSA: usb-audio: Suppress repetitive debug messages from
    retire_playback_urb()
    - LP: #1305133
  * SAUCE: (no-up) 'BUG:' message unnecessarily triggers kerneloops
    - LP: #1305480
  * [Config] CONFIG_POWERNV_CPUFREQ=m
    - LP: #1309576
  * [Config] CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y for ppc64el
    - LP: #1309576
  * [Config] CONFIG_TRANSPARENT_HUGEPAGE=n for arm64
    - LP: #1309221
  * [Config] CONFIG_MEMCG_KMEM=y
    - LP: #1309586
  * [Config] CONFIG_CRASH_DUMP=y for ppc64el
    - LP: #1312783

  [ Upstream Kernel Change...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.16.0-22.29

---------------
linux (3.16.0-22.29) utopic; urgency=low

  [ Tim Gardner ]

  * Release Tracking Bug
    - LP: #1379321

  [ Andrew Morton ]

  * SAUCE: (no-up) mm-introduce-a-general-rcu-get_user_pages_fast-fix
    - LP: #1309221
  * SAUCE: (no-up) arm64-mm-enable-rcu-fast_gup-checkpatch-fixes
    - LP: #1309221

  [ Andy Whitcroft ]

  * [Config] CONFIG_PATA_MACIO=y
    - LP: #1378894
  * [Config] enable cloud tools on i386
    - LP: #1367399
  * SAUCE: scsi: hyper-v storsvc switch up to SPC-3
    - LP: #1354397
  * SAUCE: powerpc -- fix mm/slice.c switch include to linux/hugetlb.h

  [ dann frazier ]

  * [Config] CONFIG_HAVE_GENERIC_RCU_GUP=y
    - LP: #1309221

  [ Feng Kan ]

  * SAUCE: (no-up) power: reset: Add generic SYSCON register mapped reset
    - LP: #1284433
  * SAUCE: (no-up) arm64: dts: Add X-Gene reboot driver dts node
    - LP: #1284433

  [ Ian Munsie ]

  * SAUCE: (no-up) powerpc/cell: Move spu_handle_mm_fault() out of cell platform
  * SAUCE: (no-up) powerpc/cell: Move data segment faulting code out of cell platform
  * SAUCE: (no-up) powerpc/cell: Make spu_flush_all_slbs() generic
  * SAUCE: (no-up) powerpc/msi: Improve IRQ bitmap allocator
  * SAUCE: (no-up) powerpc/mm: Export mmu_kernel_ssize and mmu_linear_psize
  * SAUCE: (no-up) powerpc/powernv: Split out set MSI IRQ chip code
  * SAUCE: (no-up) cxl: Add new header for call backs and structs
  * SAUCE: (no-up) powerpc/powerpc: Add new PCIe functions for allocating cxl interrupts
  * SAUCE: (no-up) powerpc/mm: Add new hash_page_mm()
  * SAUCE: (no-up) powerpc/opal: Add PHB to cxl mode call
  * SAUCE: (no-up) powerpc/mm: Add hooks for cxl
  * SAUCE: (no-up) cxl: Add base builtin support
  * SAUCE: (no-up) cxl: Driver code for powernv PCIe based cards for userspace access
  * SAUCE: (no-up) cxl: Add userspace header file
  * SAUCE: (no-up) cxl: Add driver to Kbuild and Makefiles
  * SAUCE: (no-up) cxl: Add documentation for userspace APIs
  * SAUCE: (no-up) cxl: Fix afu_read() not doing finish_wait() on signal or non-blocking

  [ John Johansen ]

  * SAUCE: Revert: fix: only allow a single threaded process to ...
    - LP: #1371310

  [ Steve Capper ]

  * SAUCE: (no-up) mm: introduce a general RCU get_user_pages_fast()
    - LP: #1309221
  * SAUCE: (no-up) arm: mm: introduce special ptes for LPAE
    - LP: #1309221
  * SAUCE: (no-up) arm: mm: enable HAVE_RCU_TABLE_FREE logic
    - LP: #1309221
  * SAUCE: (no-up) arm: mm: enable RCU fast_gup
    - LP: #1309221
  * SAUCE: (no-up) arm64: mm: enable HAVE_RCU_TABLE_FREE logic
    - LP: #1309221
  * SAUCE: (no-up) arm64: mm: enable RCU fast_gup
    - LP: #1309221

  [ Tim Gardner ]

  * SAUCE: Added bnx2x/bnx2x-e1-7.8.19.0.fw
    - LP: #1378491
  * [Config] CONFIG_CXL=m
  * [Config] CONFIG_POWER_RESET_SYSCON=y for arm64
  * SAUCE: (no-up) Restrict CONFIG_POWER_RESET_SYSCON to arm64 only

  [ Upstream Kernel Changes ]

  * powerpc: implement vmemmap_list_free()
    - LP: #1378413
  * powerpc: implement vmemmap_remove_mapping() for BOOK3S
    - LP: #1378413
  * powerpc: implement vmemmap_free()
    - LP: #1378413
  * powerpc: start loop at section start of start in vm...