Low memory, apps crashing - change zram settings or add swapfile? [4.x]

Have the same Problem and it is anoying as hell! It happens not only once a day, that all apps or at least all android apps are closed while phone is laying arround. No Android, no Nextcloud talk messages are ariving anymore. You only get notice of it if you get a call, asking for response :confused:

4.2.0.21 does not make anything better!

Has someone reported this via zendesk? Maybe none of the responsible at Jolla is reading hereā€¦

Just wanted to document what I did on my Xperia 10 ii 4.3.0.12 in case it may help someone (thanks for all the information in your posts) :

dd if=/dev/zero of=/swapfile bs=1M count=1024
chmod 600 swapfile
mkswap /swapfile
swapon /swapfile

then edited ā€œ/vendor/etc/fstab.pdx201ā€ to reduce zram to 500M and mount the swap file :

...
# ZRAM/SWAP          
/dev/block/zram0                           none                  swap     defaults     
/swapfile                                  none                  swap     sw              0       0
...

I find the result quite dramatic (positively) especially for android apps, and its seems to resist in time and reboots. 1GB swap is probably overkill though.

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Thanks for sharing your experiences! Does the entry for the /swapfile really work for you on a reboot? Somehow in my case the swapfile does not get mounted on a XA2. The only difference is that I made the swap on /home/swapfile instead directly in root. Does this matter somehow?

I can confirm that komoot is crashing after some minutes of usage. No other apps open or in background at this time. This is valid for all other navigation apps I am using - OSM and Here. I am on a XA2 and discovered this behavior with the latest version of Sailfish. Can not remember seeing this before.

Yes, it gets mounted at boot :

[defaultuser@Xperia10II-DualSIM ~]$ cat /proc/swaps
Filename Type Size Used Priority
/dev/zram0 partition 524284 311104 -2
/swapfile file 1048572 0 -3

/swapfile is owned by root and rw-------.

Ah OK. I checked if the swapfile in the root directory gets automounted and it works.
Here are the two lines in the fstab:
/home/swapfile none swap defaults 0 0 doesnā€™t work
/swapfile none swap defaults 0 0 works

Great, thanks for the feedback.

After some testing with an additional swapfile I can say that the problem still exist. Navigation Apps still crashing after some minutes. I can see that swap is growing after start but with a maximum of 150MB. Memory used is growing from 1,3GB in idle without any apps to ~1,8GB then crashing. How much memory do your devices consume after start without any other apps?

That is really not a good metric with Linux kernels which follow the ā€œfree RAM is wasted RAMā€ philosophy. On a properly working system you could see 99% used memory all the time and nothing crashing.

The whole thing is made even more complicated on SFOS where the native side and the Android side use different technologies for dealing with low memory situations - and the technologies used differ from device to device and release to release.

See also:

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Thanks for the hints. By used memory I meant the active memory. There was a bunch of cached and buffered memory too so that free memory was something round 40MB before crash. After studying the links in your post I understand the problem better.

Tested this on XZ2c, and definitely improves thingsā€¦ Infortunately, my remaining system memory is barely over 1g as is. Maybe will test 750 or somethingā€¦

Unfortunately it got worse with 4.4.0.58.
Browser update (bigger memory consumption) causes problems with other apps. :frowning:

I recently acquired a SanDisk Extreme Pro 64GB memory card. Specs says it puts out 170 MB/s read and 90 MB/s write. On my Xperia 10 II I disabled system swap and enabled swapfile on sd only. I also messed with swappiness to test things out. 6 android apps and 4 system. Device is noticeably slower when switching apps but overall very stable. Once app is switched it acts normal. I need to test things some more but it seems that sd can be a replacment for internal swap. Anyway, I would like to test performance with both swaps equal size (internal and sd) mounted with equal priorities. In theory this should ads up speed of sd and internal, or am I wrong?

Iā€™m not sure itā€™s a good idea to add SWAP on your SD Cardā€¦
Usually, the less you write on a SD Card the more its longevity increases.

But this is exactly the point of it. sd card is replaceable internal memory is not.

But if not, anybody have an idea how to grant equal prios to each swap, internal and sd?
No matter what I do they end up beeing different :confused:

Hi again

Can someone explain how to run two swap places with equal priorites? No matter what value I set both swaps ends up with different prios,

Also, did someone figured out how to apply custom swap places and swappiness settings at startup?

For swappiness, Iā€™d try standard sysctl approach; for some reason thereā€™s no sysctl.conf on Sailfish, but you can create file ā€“ letā€™s name it local-swappiness.conf in /etc/sysctl.d and put

vm.swappiness = 90

(whatever value you see fitting) in there. Name is irrelevant, I used local- prefix to avoid potential conflicts, just remember the .conf extension is needed.

Can you show, how do you try to set swap priority?

Will this also work with swap settings as decribed below?:
swapoff /dev/zram0
swapon -p 2 /run/media/defaultuser/6239-3830/swap
swapon -p 2 /dev/zram0

This gives me two equal swap spaces with equal priorities and this indeed works nice, 6 android and 6 system apps were around full ram and 75% of swap and everything worked stable. I previously tried giving minus somethings priority value but it didnā€™t work for unknown reason, giving it prios above 1 works.
It just would be nice to have this on startup rather than typing this into terminal each time I reboot :confused:

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If nobody wants to fix me with right solution for changing swap settings automaticly maybe there is one person which can point me into right direction? Is there a place where I can put executable script?
What is the full path of swapon & swapoff?

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Bumping it up, please somebody help

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