Disabling semantic-desktop at runtime

Today we bumped  KDE SC 4.11 beta 1 (4.10.80) in the gentoo kde overlay. The semantic-desktop use flag is dropped in >=kde-base/4.10.80, as you may already noticed or read in dilfridges blog post. So if your hardware is not powerful enough or you just don’t want to use the feature you can easily disable it at runtime.

1. Go to the “System Settings” and search for “Desktop Search”

System Settings


2. Uncheck at least the file and email indexer. You can also disable the “Nepomuk Semantic Desktop”.

Desktop Search Settings

Have fun!



If you want to disable Akonadi you can check out this blog post.


19 thoughts on “Disabling semantic-desktop at runtime”

  1. Unfortunately in my setup the “Desktop Search” icon is
    missing. (Do you know which ebuild provides it?)
    I had to disable all these settings by hand…

  2. >1. Go to the “System Settings” and search for “Desktop Search”

    which needs the USE flag enabled before, right ?

  3. That’s just half the way to replace “-semantic-desktop” on runtime. USE=”semantic-desktop” also controlled dependency on akonadi – how to catch this on runtime would have been way more interesting. Every clock by default enables “show events”. This option needs to be disabled. There are several runners in KRunner that would need to be disabled.
    If one option get’s missed akonadi automatically will get started – together with mysql, which can take quite some memory.

    1. Akonadi does not realy need much performance. I found another blog post which describes the steps to disable it. Maybe it helps you, though its for KDE 4.7.

  4. Make it disabled by default as it used to be. This is pretty much useless features and majority of users won’t be using it. However, it takes a lot of resources which will reflect on the customer experience overall.
    How would you like it if it would be 100 small ticks like that in different places and all needed to be disabled to make it usable???

    1. Disabling is not supported by upstream. We had several hacks in our ebuilds to make it possible, but it turned out while tracking 4.11 development (kde-base/*-9999.ebuilds) that it would be much harder (adding more hacks) to support an unsupported option.

      AND I don’t think that nepomuk is useless. In 4.11 the performance will be much better than in older releases.


  5. Well, this just sucks. Not only does it pull in and build lots of unnecessary packages (virtuoso-odbc, libiodbc, virtuoso-server, soprano, shared-desktop-ontologies, nepomuk-core, nepomuk-widgets), it forces akonadi and friends on you as well. And that blog post about Akonadi points out that you can’t ever really turn it off, something is always going to be turning it back on.

    In the Windows world, they have a name for this kind of thing: Spyware/Malware. It fits the definition to a “T”.

    1. As long as the packages are needed to full fill upstream requirements, the packages are not unnecessary.

      I cant see where nepomuk and friends are spyware. Show me the source code lines and we will patch it.

  6. I think you at least could update your post and link to the post you found about disabling akonadi. Even if you think it does not interfere there are many users out there who just don’t want mysql running – it really needs quite some MB.

    A short anekdote:
    I updated to kde-4.10.4, took the +semantic-desktop.I needed to wipe my nepomuk DB + akonadi cache. (KDE users might know this: they use tagging and all that fancy stuff, then something breaks and the only way to fix this is to wipe the db…) Need to say that I had +semantic-desktop during 4.9.x but got sick of it (performance,stability,…) so took the “-semantic-desktop”-way. After all those posts about improvement to kdepim and nepomuk in 4.10 I simply gave it another chance.
    After the update I did a reboot (new kernel, too). And akonadi started, because I missed the events settings – enabled them to see if I can get some benefits, before completeley disabling semantic-desktop again in 4.10.1.
    The result: The imap resource managed to remove the timestamp of quite some emails. I really hope it did not delete mail bodies. This change was pushed on the server, so these mails even have no timestamp in claws…

  7. The ironic part of all this is: KDE 4.11 beta 1 seems to be so much faster than any KDE before it that this point would be moot. Just tested the relevant parts, and the performance differential is way too much. Vishesh wasn’t joking about claiming Nepomuk was 7x faster: it feels that way.

    1. It’s seven time quicker at doing something I don’t care! Ah, the progress! 🙂
      To me, if it takes more than zero CPU cycles, it takes too much.

      I don’t get why it’s no more possible to disable the whole thing (not just Nepomuk at runtime but also Akonadi, and all dependencies) on KDE >4.10. AFAIK the KlyDE project doesn’t include semantic-desktop, so I have to ask: it’s because of something that openSUSE can do but Gentoo cannot? I refuse to believe it.

        1. So, it’s possible but not something you want to do. No problem with that, it’s just to be clear. 🙂

          If I knew ebuilds as much as know RPM specs, I’d try to build a KlyDE overlay myself. And if I had enough spare time, of course! *sigh*

  8. At least with KDE 4.10.4 there’s no icon, even after removing the -semantic-desktop USE flag from make.conf.
    Could it be that there’s some auto-magic dependency during built time for the appropriate icon/widget ?
    Well -4.10.5 is short before GE, so I’ll look at that version end of this week.

  9. It got pushed to portage

    This just makes the last parts of kde i was still fond of unusable to me. i’m not going to be installing nepomuk. Ever. Disabling it at runtime is ridiculously not-gentoo. not to mention i don’t even have system-settings. I’ll keep using my system without having to scramble to make sure indexing software is turned off every update. Thanks for the 3.5.x days.

    but now i even have to let k3b, kate and kcalc go.

    Clearly i’m no longer the target audience. Goodbye.

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