This bug was fixed in the package systemd - 204-0ubuntu19
---------------
systemd (204-0ubuntu19) saucy; urgency=low
* Add 0031-ignore-omap-vsync.patch: Gross, but effective hack to ignore
VSYNC change uevents from omapfb, as they happen at each vsync and thus
keep waking up udevd (including rules processing), upstart, and other
parts of the system 60 times a second. (LP: #1234743)
-- Martin Pitt <martin.p...@ubuntu.com> Thu, 17 Oct 2013 12:01:42 +0200
** Changed in: systemd (Ubuntu Saucy)
Status: New => Fix Released
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https://bugs.launchpad.net/bugs/1234743
Title:
omapfb module floods system with udev events on samsung galaxy nexus
Status in Upstart:
Fix Released
Status in “linux” package in Ubuntu:
Invalid
Status in “lxc-android-config” package in Ubuntu:
Invalid
Status in “powerd” package in Ubuntu:
Fix Released
Status in “systemd” package in Ubuntu:
Fix Committed
Status in “linux” source package in Saucy:
Invalid
Status in “lxc-android-config” source package in Saucy:
Invalid
Status in “powerd” source package in Saucy:
Fix Released
Status in “systemd” source package in Saucy:
Fix Released
Status in “linux” source package in Trusty:
Invalid
Status in “lxc-android-config” source package in Trusty:
Invalid
Status in “powerd” source package in Trusty:
Fix Released
Status in “systemd” source package in Trusty:
Fix Committed
Bug description:
[SRU justification]
On the Galaxy Nexus (maguro) phone, the video driver wakes up udev and
upstart 60 times a second sending "vsync" uevents. This is a deeply flawed
driver design, but we can't easily change it because the userspace side of the
driver relies on the current behavior. The only feasible workaround is to have
udev filter out these events, so that the device isn't kept busy (with about 5%
load) waking up system daemons.
[Test case]
1. Install the updated package on an x86 system.
2. Reboot.
3. Confirm that the machine boots successfully.
4. Install the updated package on a non-maguro arm system.
5. Reboot.
6. Confirm that the machine boots successfully.
7. Install the updated package on a maguro system.
8. Reboot.
9. Confirm that the machine boots successfully.
10. Confirm using 'top' that udev is not taking up a significant percentage
of the CPU time.
[Regression potential]
This is a change to a core system daemon, and while the code change is
guarded by an architecture check, we should be careful about updating such a
core package which could cause regressions, in particular on other ARM devices.
The test case should guard against this by ensuring we verify the effect of
this change on non-maguro systems prior to releasing the SRU.
Playing an mp4 on a Samsung Galaxy Nexus using today's image (3 Oct
2013) for 30 minutes I observed that init is busy and also consuming
heap quite rapidly.
Attached is the output from running health-check (found in PPA:colin-
king/white) on init pid 1114.
Key points:
1. messages being read/written at ~600 messages a second, hence the high
context switch rate and ~4.9% CPU load.
2. heap consumption: ~30K a second using brk() and 2K a second via mmap
To reproduce:
Install health-check:
sudo add-apt-repository ppa:colin-king/white
sudo apt-get update && sudo apt-get install health-check
Download a large mp4 to the phone. Keep screen from blanking using:
sudo powerd-cli display on bright &
then play the mp4:
dbus-launch mediaplayer-app test.mp4
--desktop_file_hint=/usr/share/applications/mediaplayer-app.desktop
--stage_hint=main_stage
And then observe that init is busy for 300 seconds:
ps -e | grep init
1 ? 00:02:56 init
348 ? 00:00:00 init
1114 ? 00:03:22 init
sudo health-check -p 1114 -d 300
Attached are my results for a 30 minute run.
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