<![CDATA[How use less RAM for embedded qt application on linux ARM?]]>When I start my ARM board, I see Linux and some init programs use around 11MB memory.
If I then start my (quite large) Qt applictaton (with GUI, network, video,...) , the used RAM rises to 95MB.

After a while this increases even further to around 120MB, and the device only has 122MB available.
This is obviously not good, and I want to lower the memory usage.

How can I use less RAM for embedded qt applications on linux ARM? Or are these large memory requirements normal for Qt?

PS: I tried using a swap file and then memory + swap usage is relatively steady, so I assume it's not a memory leak.
(117MB used + 15MB swap)

]]>https://forum.qt.io/topic/63362/how-use-less-ram-for-embedded-qt-application-on-linux-armRSS for NodeFri, 17 Apr 2026 20:59:08 GMTTue, 26 Jan 2016 14:45:27 GMT60<![CDATA[Reply to How use less RAM for embedded qt application on linux ARM? on Tue, 26 Jan 2016 15:17:17 GMT]]>@QtFriend
not only file size will decrease but also the memory allocation by objects.
But of course you also need to inspect your source code for memory efficiency.
Using pointers and references as much as possible, object reusage, etc

]]>https://forum.qt.io/post/309674https://forum.qt.io/post/309674Tue, 26 Jan 2016 15:17:17 GMT<![CDATA[Reply to How use less RAM for embedded qt application on linux ARM? on Tue, 26 Jan 2016 15:14:20 GMT]]>Hi! These libraries themselves pull in other libraries from your system.

]]>https://forum.qt.io/post/309673https://forum.qt.io/post/309673Tue, 26 Jan 2016 15:14:20 GMT<![CDATA[Reply to How use less RAM for embedded qt application on linux ARM? on Tue, 26 Jan 2016 15:11:09 GMT]]>Thanks raven-worx.

The used qt shared libraries have the following sizes:
Core = 2.9MB
GUI = 8.7MB
Network = 907kB
Phonon = 277kB

If I use all these shared libraries I only get to ~12.8MB. This is very acceptable, and reducing some features will bring this down a little, perhaps to 10MB combined, but not tens of MB. Or am I misunderstanding?

]]>https://forum.qt.io/post/309670https://forum.qt.io/post/309670Tue, 26 Jan 2016 15:11:09 GMT<![CDATA[Reply to How use less RAM for embedded qt application on linux ARM? on Tue, 26 Jan 2016 14:57:49 GMT]]>@QtFriend
i guess since you are using some Qt modules your best chance is to recompile Qt and disable certain features you do not need.
This mainly decreases the size of the shared libraries and thus also the memory consumption.

]]>https://forum.qt.io/post/309663https://forum.qt.io/post/309663Tue, 26 Jan 2016 14:57:49 GMT