Comment 19 for bug 289338

and here's my 2 {$COIN_DENOMINATOR}
Summary:
 kio_thumbnails really missbehaves by stealing memory for me too (+1.7G DATA as reported by top this morning). Can't say about the CPU usage as it fills RAM and swap causing massive swapping => skyrocketing my load avg to +30.0, top says mostly (+95%) io wait untill I manage to kill the kio_thumnail process (or processes)), this probably due to thrashing caused by the exess memory theft. (I'm puzzled as to why it's not OOM killed!)
Versions:
 OS: Gentoo
 kde-base/kdebase-kioslaves-4.3.0
 (build with USE=debug so it should be possible to get some
  useful debuggging info, not sure how though)

 $ kde4-config --version
     Qt: 4.5.1
     KDE: 4.3.00 (KDE 4.3.0)
     kde4-config: 1.0

Reproduce:
 It usually starts by hovering big movie files or folders with big movies files. Though it shouldn't thumbnail them, max previev file size is set to 5 MB (the movies as much bigger than that), the thumbnails button isn't checked. Further more only "Grafik" (I'm 'guessing' the non localized string is "graphics") and Jpeg is selected. And "Använd miniatyribilder inbäddade i filer" (~= "use embedded thumbnails"/"use thumbnails embedded in files").
 * Clearly kio_thumbnails/dolphin isn't respecting those options. - maybe this is a konqueror/dolphin bug? (otho, imo thumbnailing a file shouldn't consume more than _tops_ 10M RAM, or perhaps I'm living in a fantasy world?)

Work-around:
 I've temporarily renamed kio_thumbnail.so to kio_thumnail.so.disabled, since it's a hazard to the system's stabillity right now.

Wish:
 A kill-switch for kio_thumbnail, i.e. a "Never generate thumbnails" option, if so only accessible via manually editing ~/.kde4/share/config/kio_thumbnailrc. Or a hard memory limit option there, say 100M (which imo is too much, but at least a limit that should prevent grand-theft-ram).
 Or better yet, a real fix that makes kio_thumbnail use a reasonable amount or RAM when generating thumbs.