[Bug 1537635] Re: Reduce zlib compression level for massive performance increase

[Launchpad Bug Tracker]

This bug was fixed in the package apport - 2.20.11-0ubuntu2

---------------
apport (2.20.11-0ubuntu2) eoan; urgency=medium

  * test/test_backend_apt_dpkg.py: as of r3211 an error is not raised if the
    binary is not found. Cherry picked from upstream r3248.
  * backends/packaging-apt-dpkg.py: writing the contents mapping pickle file
    can Traceback on systems with little memory so don't write it. Cherry
    picked from upstream r3250.
  * test/test_apport_valgrind.py: skip test_sandbox_cache_options if system
    has little memory.

 -- Brian Murray <brian at ubuntu.com>  Mon, 20 May 2019 18:39:46 -0700

** Changed in: apport (Ubuntu Eoan)
       Status: In Progress => Fix Released

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to apport in Ubuntu.
https://bugs.launchpad.net/bugs/1537635

Title:
  Reduce zlib compression level for massive performance increase

Status in Apport:
  Fix Released
Status in apport package in Ubuntu:
  Fix Released
Status in apport source package in Eoan:
  Fix Released

Bug description:
  When apport takes a core dump of a large application, it uses 100% CPU
  for a _long_ time (often 30 seconds or more) to compress the core
  dump. The system is virtually unusable during this time, especially if
  the application was the window manager and won’t be restarted until
  the core dump is complete.

  This is a longstanding known problem; it motivated the switch from
  bzip2 to zlib level 9 back in apport 0.24. That made it much better,
  but it’s still quite bad. So why not switch from zlib level 9 to zlib
  level 1?

  I tested this on a core dump of gnome-shell, and while it increased
  the size of the .crash file by 24% (68.5 MB to 85.0 MB), it decreased
  the needed CPU time by a FACTOR OF EIGHT (58.6 seconds to 7.3
  seconds). This tradeoff seems more than worthwhile for this use case.

To manage notifications about this bug go to:
https://bugs.launchpad.net/apport/+bug/1537635/+subscriptions