[SRU] fcitx 100% CPU usage on rare case

[Aron Xu]

[Impact]

There is a rare case that fcitx runs at 100% CPU when using Sogou Pinyin input method that sometimes happen after suspend/resume, even though the problem does not break client usages, it will drain battery of laptop and makes fan very noisy.

[Test Case]
After upgrading the package, user will not see 100% CPU usage of fcitx after frequent suspend/resume.

[Regression Potential]
The patch limits the call of accept() to be less than 21 times, and the calling code already has error handling when the returning value is less than 0, so the possibility of regression is minimal.

[Brian Murray (brian-murray)]

Hello Aron, or anyone else affected,

Accepted fcitx into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/fcitx/1:4.2.9.1-1ubuntu1.16.04.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Brian Murray (brian-murray)]

Hello Aron, or anyone else affected,

Accepted fcitx into yakkety-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/fcitx/1:4.2.9.1-4ubuntu1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Aron Xu (happyaron)]

I've verified with updated package for couple of days, not seeing CPU 100% anymore.

[Brian Murray (brian-murray)]

Did you test both releases?

[Brian Murray (brian-murray)]

Actually given that yakkety failed to build on all architectures, I guess you tested xenial but I wonder why you marked this verification-done-yakkety. How exactly are you doing your testing?

[Aron Xu (happyaron)]

@Brian, I meant xenial only, the yakkety version depends on LP: #1657677 to have the package buildable.

[Robie Basak (racb)]

The verification of the Stable Release Update for fcitx has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package fcitx - 1:4.2.9.1-1ubuntu1.16.04.2

---------------
fcitx (1:4.2.9.1-1ubuntu1.16.04.2) xenial; urgency=medium

  * debian/patches/0014-exit-the-loop-after-trying-20-times.patch:
    Avoid 100% CPU usage on rare case (LP: #1652591)

 -- Aron Xu <email address hidden> Mon, 26 Dec 2016 11:58:13 +0000

[Aron Xu (happyaron)]

As LP: #1657677 is released, the package for yakkety build was completed. I've tested the package from yakkety-proposed and it works for me, tagging verification-done.

[Launchpad Janitor (janitor)]

This bug was fixed in the package fcitx - 1:4.2.9.1-4ubuntu1

---------------
fcitx (1:4.2.9.1-4ubuntu1) yakkety; urgency=medium

  * debian/patches/0014-exit-the-loop-after-trying-20-times.patch:
    Avoid 100% CPU usage on rare case (LP: #1652591)

 -- Aron Xu <email address hidden> Sun, 25 Dec 2016 15:12:03 +0800

[Huang Chenliang (huangclpku)]

I still suffer from the 100% cpu problem frequently. I have to restart fcitx more than once per hour by using fcitx -r.
I have fcitx version 4.2.9.1 on my ubuntu 16.04 system.