KInit - Current state and benchmarks
david at davidedmundson.co.uk
Mon Jun 17 10:56:15 BST 2019
>Using kdeinit to launch KDE applications makes starting a typical KDE applications 2.5 times faster (100ms instead of 250ms on a P-III 500)
Certainly sounds like a good thing.
===The current State===
* Apps launched from the plasma menu skip klauncher and therefore
kinit. This was done due to the API for KRun blocking somewhere
(Though I don't remember details)
This seems like something easily fixable if we tried.
* Processes launched on bootup (with the exception of kcminit,
ksmserver and kded5) skip kinit. This was due to a deadlock in
klauncher and ksmserver at the time when apps autostart moved from
This deadlock is since resolved in my ksmserver splitting branches.
* But Plasma apps launched from the desktop do go through klauncher
(and therefore kinit)! So we're not even consistent.
* The number of applications linking kinit properly under KF5 is in an
equally sorry state.
Dolphin does, but even core applications like Okular and Kate don't.
$ find -name 'CMakeLists.txt' -print0 | xargs -0 grep
for a local list.
* It's also incompatible with flatpak/snaps/appimage, which is a rising trend
Kinit is still also used for spawning KIO slaves.
===Is it still useful?===
We're not using it properly and we need to do something. Either fix it
or start to phase it out officially.
Since the time of writing kinit Qt has changed a lot. linking has
changed a bit. CPUs have changed a lot and Hard Disks have changed a
So I wrote a benchmark tool to see if the initial speed boost claim is
My test does the following:
- creates a dummy (headless) wayland server
- spawns an app using either QProcess or sending a DBus message to KLauncher
- times how long it takes for the first window to appear, timing the
more important real world metric and one that includes all the
(Showing the median out of 5 runs on a mid range SSD desktop)
Dolphin QProcess: 348
Dolphin Kinit: 332
KCalc QProcess: 242
KCalc KInit: 232
Plasmoidviewer (patched) QProces: 622
Plasmoidviewer (patched) KInit: 591
KWrite QProcess: 391
KWrite Kinit: 390
(unsurprisingly similar as kwrite does not have a kdeinit exec, I
included it as it shows the others aren't false positives)
===What about memory?===
Good question. It needs a similar investigation by someone who
My test implies there /is/ a genuine saving with kinit !
However it's far from the claimed 2.5 times faster, it is less than
1.1 times faster. Saving up to 30ms.
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