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Bug #10487

Improve VM and OOM settings for erasing memory

Added by intrigeri almost 4 years ago. Updated over 3 years ago.

Status:
Resolved
Priority:
Normal
Assignee:
-
Category:
-
Target version:
Start date:
11/05/2015
Due date:
% Done:

100%

Feature Branch:
bugfix/10487-improve-VM-and-OOM-settings-for-erasing-memory
Type of work:
Code
Blueprint:
Starter:
Affected tool:

Description

The test suite in feature/jessie has good reasons to set oom_kill_allocating_task to 0, and /proc/sys/vm/overcommit_memory to 0. These reasons probably apply as-is to local-includes/usr/share/initramfs-tools/scripts/init-premount/sdmem.


Related issues

Related to Tails - Bug #9705: Update the memory erasure automated tests for Jessie Resolved 07/08/2015 01/15/2016
Related to Tails - Bug #9707: Jessie: System sometimes does not poweroff after memory erasure Rejected 07/08/2015
Related to Tails - Bug #10733: Run our initramfs memory erasure hook earlier Resolved 12/09/2015

Associated revisions

Revision ca9cf70a (diff)
Added by intrigeri almost 4 years ago

Don't forcefully overcommit memory when erasing memory on shutdown.

Overcommitting memory seems too likely to trigger kernel freezes.

Refs: #9707, #10487.

Revision bfa09055 (diff)
Added by intrigeri almost 4 years ago

Don't kill the allocating task when erasing memory on shutdown.

The kernel's default (0) that we enforce here is to kill the hoggers, which will
be our sdmem instances.

Killing the allocating task may have been sound in the past, but it feels too
risky these days, given early boot (initramfs) sees increasing concurrency.

Refs: #9707, #10487.

Revision 552bab73 (diff)
Added by intrigeri almost 4 years ago

Make sure the kernel doesn't starve from memory during memory erasure.

We want to set it to the lowest possible value, to maximize the coverage
of memory erasure. But Documentation/sysctl/vm.txt for
vm.min_free_kbytes says: "if you set this to lower than 1024KB, your
system will become subtly broken, and prone to deadlock under high
loads". With 2048KB I've seen freezes, so let's not modify the kernel
default (8192KB on x86_64 currently).

Refs: #9707, #10487.

History

#1 Updated by intrigeri almost 4 years ago

  • Related to Bug #9705: Update the memory erasure automated tests for Jessie added

#2 Updated by intrigeri almost 4 years ago

  • Related to Bug #9707: Jessie: System sometimes does not poweroff after memory erasure added

#3 Updated by intrigeri almost 4 years ago

  • Feature Branch set to bugfix/10487-improve-VM-and-OOM-settings-for-erasing-memory

Giving it a try, wondering if this could help with #9707.

#4 Updated by intrigeri almost 4 years ago

  • Status changed from Confirmed to In Progress
  • % Done changed from 0 to 10

#6 Updated by intrigeri almost 4 years ago

  • Related to Bug #10733: Run our initramfs memory erasure hook earlier added

#7 Updated by intrigeri almost 4 years ago

  • Assignee set to intrigeri
  • Target version set to Tails_2.0

#8 Updated by intrigeri almost 4 years ago

  • Assignee changed from intrigeri to anonym
  • % Done changed from 10 to 50
  • QA Check set to Ready for QA

Please review, test and merge into feature/jessie.

#9 Updated by intrigeri almost 4 years ago

  • Status changed from In Progress to Fix committed
  • Assignee deleted (anonym)
  • % Done changed from 50 to 100
  • QA Check changed from Ready for QA to Pass

This was merged today.

#10 Updated by anonym over 3 years ago

  • Status changed from Fix committed to Resolved

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