Fix OOM errors

[Paolo Pisati]

SRU:
The original report for this bug is this one:

http://bugs.launchpad.net/bugs/1655842

but since the raspi2 kernel has a well isolated solution that doesn't affect (and doesn't apply) to the other kernels mentioned there, i decided to spawn this bug and use it as a reference instead of polluting the above LP bug with details and information that don't pertain there.

Impact:
People are reporting OOM errors on RaspberryPI2/3, in particular when running
KDE or chromium, and the problem disappears when they go back to a kernel previous
than 4.4.0-1044.51.

This is actually a fallout from a previous attempt to fix a memory corruption in the usb stack and that was triggered during boot when mmc was mounted:

BugLink: http://bugs.launchpad.net/bugs/1665280

While trying to 'fix' the above problem, some patches that deal with OOM and memory presseure situaions were reverted and led to this situation - by reverting back these changes we fix the OOM errors (see comments #90, #91, #92 and #93 in the original LP bug) as reported by users, while the memory corruption problem doesn't show up anymore.

Fix:
Test a kernel with the following reverts reverted:

080aca8 Revert "mm: consider compaction feedback also for costly allocation"
486bab1 Revert "mm, oom, compaction: prevent from should_compact_retry looping for ever for costly orders"
7b84469 Revert "mm, oom: protect !costly allocations some more for !CONFIG_COMPACTION"
19724e4 Revert "mm, oom: prevent premature OOM killer invocation for high order request"
4b8b650 Revert "PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspend"

How to test:
People have reported out of memory erros while running KDE and/or chromium, so the best way to reproduce this problem is to install KDE, open ~20 konqueror windows, execute chromium, and opens ~10 tabs on different web sites - if the kernel doesn't oops, the fix is working.

[Kleber Sacilotto de Souza (kleber-souza)]

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-xenial' to 'verification-done-xenial'. If the problem still exists, change the tag 'verification-needed-xenial' to 'verification-failed-xenial'.

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!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-raspi2 - 4.4.0-1074.82

---------------
linux-raspi2 (4.4.0-1074.82) xenial; urgency=low

  * linux-raspi2: 4.4.0-1074.82 -proposed tracker (LP: #1716618)

  [ Ubuntu: 4.4.0-96.119 ]

  * linux: 4.4.0-96.119 -proposed tracker (LP: #1716613)
  * kernel panic -not syncing: Fatal exception: panic_on_oops (LP: #1708399)
    - s390/mm: no local TLB flush for clearing-by-ASCE IDTE
    - SAUCE: s390/mm: fix local TLB flushing vs. detach of an mm address space
    - SAUCE: s390/mm: fix race on mm->context.flush_mm
  * CVE-2017-1000251
    - Bluetooth: Properly check L2CAP config option output buffer length

linux-raspi2 (4.4.0-1073.81) xenial; urgency=low

  * linux-raspi2: 4.4.0-1073.81 -proposed tracker (LP: #1715653)

  [ Ubuntu: 4.4.0-95.118 ]

  * linux: 4.4.0-95.118 -proposed tracker (LP: #1715651)
  * Xenial update to 4.4.78 stable release broke Address Sanitizer
    (LP: #1715636)
    - mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base changes

linux-raspi2 (4.4.0-1072.80) xenial; urgency=low

  * linux-raspi2: 4.4.0-1072.80 -proposed tracker (LP: #1713464)

  * Include Broadcom GPL modules in Xenial Kernel (LP: #1665783)
    - [config] update config for master changes

  * Fix OOM errors (LP: #1712598)
    - Revert "Revert "mm: consider compaction feedback also for costly
      allocation""
    - Revert "Revert "mm, oom, compaction: prevent from should_compact_retry
      looping for ever for costly orders""
    - Revert "Revert "mm, oom: protect !costly allocations some more for
      !CONFIG_COMPACTION""
    - Revert "Revert "mm, oom: prevent premature OOM killer invocation for high
      order request""
    - Revert "Revert "PM / wakeirq: Fix dedicated wakeirq for drivers not using
      autosuspend""

  [ Ubuntu: 4.4.0-94.117 ]

  * linux: 4.4.0-94.117 -proposed tracker (LP: #1713462)
  * mwifiex causes kernel oops when AP mode is enabled (LP: #1712746)
    - SAUCE: net/wireless: do not dereference invalid pointer
    - SAUCE: mwifiex: do not dereference invalid pointer
  * Backport more recent Broadcom bnxt_en driver (LP: #1711056)
    - SAUCE: bnxt_en_bpo: Import bnxt_en driver version 1.8.1
    - SAUCE: bnxt_en_bpo: Drop distro out-of-tree detection logic
    - SAUCE: bnxt_en_bpo: Remove unnecessary compile flags
    - SAUCE: bnxt_en_bpo: Move config settings to Kconfig
    - SAUCE: bnxt_en_bpo: Remove PCI_IDs handled by the regular driver
    - SAUCE: bnxt_en_bpo: Rename the backport driver to bnxt_en_bpo
    - bnxt_en_bpo: [Config] Enable CONFIG_BNXT_BPO=m
  * HID: multitouch: Support ALPS PTP Stick and Touchpad devices (LP: #1712481)
    - HID: multitouch: Support PTP Stick and Touchpad device
    - SAUCE: HID: multitouch: Support ALPS PTP stick with pid 0x120A
  * igb: Support using Broadcom 54616 as PHY (LP: #1712024)
    - SAUCE: igb: add support for using Broadcom 54616 as PHY
  * IPR driver causes multipath to fail paths/stuck IO on Medium Errors
    (LP: #1682644)
    - scsi: ipr: do not set DID_PASSTHROUGH on CHECK CONDITION
  * accessing /dev/hvc1 with stress-ng on Ubuntu xenial causes crash
    (LP: #1711401)
    - tty/hvc: Use IRQF_SHARED for OPAL hvc consoles
  * memory-hotplug test...