[Bug 1864613] Re: xfwm4 very, very slow - leaking something?

Thu Apr 15 00:06:27 UTC 2021

The policy says:

"In other cases where such upstream automatic testing is not available,
exceptions must still be approved by at least one member of the Ubuntu
Technical Board."

So yes, you can ask for an exception. If you want to do that, I suggest
that you point technical-board@ at this bug.

> ...or do we need to instead do one of...

I think you'd need to do both of what you have listed there. You might
want to pick the most important fixes to cherry-pick, rather than all of
them.

> My concern is that having a pulling in individual commits creates a
version of Xfwm that doesn’t otherwise exist and is only supported by
Xubuntu and not the upstream. It also leads to more work later if any of
the unincluded bug fixes need to be fixed later.

You're certainly not the only one who has made this argument. Note
though that this concern applies equally to *any* package being updated
under this Ubuntu policy. In effect, you're saying that you disagree
with the policy in principle, rather than presenting a specific case for
why the policy should be set aside for you in this particular case due
to some exceptional circumstance.

You're entitled to disagree with Ubuntu policy, and discussion to change
the policy if it is no longer appropriate is also welcome. But if the
project were to agree with you on this specific concern, then I think it
would make sense to change the policy itself rather than grant an
exception on the basis of this specific argument. Doing otherwise would
be a contradiction of the policy itself.

There is a separate question here of what to do where automated tests
are difficult or don't make sense, as is the case I think with a GUI.
Maybe an exception could be discussed on this basis, or even a general
policy exception for GUIs.

I would like to point out that you're not being blocked from fixing this
bug pending further discussion here. If fixing this bug soon is
important to you, you can just cherry-pick the fix using the normal SRU
process.

-- 
You received this bug notification because you are a member of Ubuntu
Sponsors Team, which is subscribed to the bug report.
https://bugs.launchpad.net/bugs/1864613

Title:
  xfwm4 very, very slow - leaking something?

Status in Xfwm4:
  Unknown
Status in xfwm4 package in Ubuntu:
  Confirmed
Status in xfwm4 source package in Focal:
  In Progress
Status in xfwm4 source package in Groovy:
  Fix Released

Bug description:
  [Impact]

   * There is an error leak in the Xfwm4 compositor, causing the system
  to run slowly after some uptime.

  [Test Plan]

   * Enable the Xfwm4 compositor if it is not already. Settings Manager
  > Window Manager Tweaks > Compositor > Toggle on "Enable Display
  Compositing".

   * Use the desktop for some time. Reportedly, zooming in and out
  repeatedly can speed up the process. To zoom, hold Alt, and scroll up
  and down.

   * The system should start performing poorly after some time, with
  xfwm4 consuming much of the CPU resources.

   * Once fixed, the system should be much more performant after
  performing these tasks.

  [Where problems could occur]

   * Regression potential should be relatively low, as the release
  between 4.14.1 and 4.14.5 are bug releases.

   * With window managers, some changes could lead to different behavior
  and other broken displays. Non-AMD graphics users should also test for
  regressions.

  [Other Info]

   * Please see the Xfwm4 release notes for changes between 4.14.1 and 4.14.5: https://gitlab.xfce.org/xfce/xfwm4/-/blob/xfce-4.14/NEWS#L7-44

  [Original Report]

  After some uptime, xfwm4 is VERY slow at something, to the point that
  it's consuming 100% of CPU on a Xeon system and making the system
  entirely unusable. I don't know who is leaking what, but somebody is
  clearly leaking something.

  I don't have debug symbols, so this is the best I can get:

  Thread 1 (Thread 0x7f7b9d98af00 (LWP 27599)):
  #0  0x00007f7b9f1e8b7f in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
  #1  0x00007f7b9f1e8be2 in gdk_x11_display_error_trap_push () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
  #2  0x0000555c9582c771 in ?? ()
  #3  0x00007f7b9ee75248 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
  #4  0x00007f7b9ee7471e in g_main_context_dispatch () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
  #5  0x00007f7b9ee74ad0 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
  #6  0x00007f7b9ee74dc3 in g_main_loop_run () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
  #7  0x00007f7b9f4d2c2d in gtk_main () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
  #8  0x0000555c958222ce in ?? ()
  #9  0x00007f7b9e7861e3 in __libc_start_main (main=0x555c95821b50, argc=6, argv=0x7fffbeb91c18, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffbeb91c08) at ../csu/libc-start.c:308
  #10 0x0000555c9582249e in ?? ()

  or

  Thread 1 (Thread 0x7f7b9d98af00 (LWP 27599)):
  #0  0x00007f7b9f1e8b83 in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
  #1  0x00007f7b9f1e8be2 in gdk_x11_display_error_trap_push () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
  #2  0x0000555c9582e33a in ?? ()
  #3  0x0000555c95834f1b in ?? ()
  #4  0x0000555c958337d0 in ?? ()
  #5  0x00007f7b9f1f0f4f in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
  #6  0x00007f7b9f1f133a in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
  #7  0x00007f7b9f1b9094 in gdk_display_get_event () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
  #8  0x00007f7b9f1f0fe6 in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
  #9  0x00007f7b9ee7484d in g_main_context_dispatch () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
  #10 0x00007f7b9ee74ad0 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
  #11 0x00007f7b9ee74dc3 in g_main_loop_run () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
  #12 0x00007f7b9f4d2c2d in gtk_main () from /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
  #13 0x0000555c958222ce in ?? ()
  #14 0x00007f7b9e7861e3 in __libc_start_main (main=0x555c95821b50, argc=6, argv=0x7fffbeb91c18, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffbeb91c08) at ../csu/libc-start.c:308
  #15 0x0000555c9582249e in ?? ()

  ProblemType: Bug
  DistroRelease: Ubuntu 19.10
  Package: xfwm4 4.14.0-1
  ProcVersionSignature: Ubuntu 5.3.0-26.28-generic 5.3.13
  Uname: Linux 5.3.0-26-generic x86_64
  NonfreeKernelModules: nvidia_modeset nvidia
  ApportVersion: 2.20.11-0ubuntu8.4
  Architecture: amd64
  CurrentDesktop: XFCE
  Date: Mon Feb 24 23:18:34 2020
  InstallationDate: Installed on 2019-01-21 (399 days ago)
  InstallationMedia: Xubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.2)
  SourcePackage: xfwm4
  UpgradeStatus: Upgraded to eoan on 2019-11-10 (106 days ago)

To manage notifications about this bug go to:
https://bugs.launchpad.net/xfwm4/+bug/1864613/+subscriptions