touch-packages team mailing list archive

[Steve Langasek <steve.langasek@xxxxxxxxxxxxx>]

some thoughts upon analysis of /usr/share/apport/apport:

- apport does have support for blacklisting crash reporting for specific programs.  For programs that are critical for the UI on the phone and which cause a hard lockup of the UI while the crash report is running, we could use this blacklist as a workaround.
- apport currently calls os.nice(10) to avoid interfering with the running system while processing the crash file.  This is counterproductive when the process being retraced is critical to the system.
- apport's crash dump handling is already carefully written to avoid bottlenecks in either memory or disk writes (the crash dump is read from the kernel 1MB at a time, compressed, and written to the crash file); this should already be close to optimal (1MB may not be the optimal write block size, but it will compress to variable size anyway and we're not flushing the disk between writes so the kernel should do a better job of optimizing for us).  Thus, aside from possibly dropping the call to os.nice(), I confirm that there's not much of anywhere for us to go in improving the performance of the crash handler.  The only other thing that might improve performance is for the crashing process to simply have less mapped into memory at crash time - I guess that a crash dump of the unity system compositor would be quite large due to having graphics buffers mapped into memory?

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https://bugs.launchpad.net/bugs/1278780

Title:
  apport takes too long to write crash report, appears to lock up phone

Status in Apport:
  Confirmed
Status in Canonical System Image:
  Confirmed
Status in apport package in Ubuntu:
  Triaged

Bug description:
  I can trigger a crash easily on my phone via bug 1262711. Other bugs
  are available.

  When that happens my phone appears to freeze. I am unable to do
  anything for approximately 1 to 1.5 minutes. As a user my initial gut
  reaction is to reboot the phone, thus losing the crash report, and
  wasting my time.

  Having the phone lock up for 1.5 minutes is a terrible user
  experience. Can we fix/mitigate/workaround that?

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: apport 2.13.2-0ubuntu2
  Uname: Linux 3.4.0-3-mako armv7l
  ApportVersion: 2.13.2-0ubuntu2
  Architecture: armhf
  CrashReports:
   664:32011:110:10083:2014-02-10 15:41:18.152893384 +0000:2014-02-10 15:11:09.169231740 +0000:/var/crash/_usr_lib_arm-linux-gnueabihf_upstart-app-launch_desktop-hook.32011.crash
   640:0:110:1681527:2014-02-10 15:12:10.985193887 +0000:2014-02-10 15:12:05.639489630 +0000:/var/crash/_usr_bin_powerd.0.crash
   640:0:110:21384:2014-02-11 07:58:44.876281991 +0000:2014-02-11 07:58:44.876281991 +0000:/var/crash/_usr_sbin_system-image-dbus.0.crash
   640:32011:110:17122318:2014-02-11 09:19:49.915478726 +0000:2014-02-11 09:18:20.850439824 +0000:/var/crash/_usr_bin_unity8.32011.crash
  Date: Tue Feb 11 09:20:15 2014
  InstallationDate: Installed on 2014-02-11 (0 days ago)
  InstallationMedia: Ubuntu Trusty Tahr (development branch) - armhf (20140211)
  PackageArchitecture: all
  ProcEnviron:
   TERM=linux
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   SHELL=/bin/bash
  SourcePackage: apport
  UpgradeStatus: No upgrade log present (probably fresh install)

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