Comment 81 for bug 1502556

(In reply to Dan Mac from comment #67)
> I'm seeing a slow but steady increase in Plasma memory usage which means I
> have to reboot my system at least once a day.
>
> I see others are also pinning this on notification tray updates. The memory
> leak only seems to happen when I'm running the ownCloud client, which has an
> entry in the "Status & Notifications" area. Sounds like this happens
> whenever an application updates its notification area, since my memory leak
> is quite slow, but Transmission which updates far more frequently than
> ownCloud client apparently suffers much worse. (I don't know, I don't have
> Transmission installed)
>
> Please let me know if there are any further details or tests that may help :)
>
> Running Manjaro (ie. Arch, more or less) with Plasma 5.4.2, Qt 5.5.0,
> Frameworks 5.15.0, Apps 15.08.2.
>
> Thanks :)

You can simply restart plasmashell (kquitapp5 plasmashell && sleep 5 && plasmashell & disown). logging off/logging back in also restarts Xorg process in case it is eating up memory as well. You don't have to reboot your machine.