yashsingh1/xdaforums huggingface dataset:
[Nexus 7 Android Development] vetzki:
1. try without zram (and ksm if it is enabled)

2. not sure, but reverting back to charging only is the default android setting (at least my nexus4 acts the same way)

3. yeah mtp still crashing but it gets restarted afterwards and doesnt affect functionality
[Nexus 7 Android Development] AndDiSa:
[MENTION=5917730]Ahkah[/MENTION] I think the problem with the black screen / black background happens when there are too many applications open in parallel and another application needs to be started. In that case the resource providers are beeing killed and the background image as a resouce cannot be accessed any longer. Unfortunately later on the reference to the unavailable image remains still configured and so a black image / screen is beeing displayed.
[Nexus 7 Android Development] chall32:
I'm not 100% convinced that all of the slowdown is due to internal storage. I've installed HTC Boost https://play.google.com/store/apps/details?id=com.htc.pitroad and set it to smart boost (settings > smart boost in the background). Immediately my grouper felt snappier and remained snappy. Give it a go! :good:

Nice! Will give this a go too.

I've found KSM in in performance control, where do you disable zram?
[Nexus 7 Android Development] vetzki:
swapoff -a or swapoff /dev/zram0 (not quite shure about the path) as root user should disable it (until reboot)

maybe AndDiSa can add a ro. property and change init.grouper.rc so that swapon_all is only executed if ro. property matches 1 (or something like that) ?
[Nexus 7 Android Development] Troublicious:
Hi all, l have the exact same problem with grouper going veeeeeeeeeeery slow after one day or some use: this doesn't happen in may or june builds. The only solution is to reboot …
[Nexus 7 Android Development] vetzki:
[MENTION=2656725]chall32[/MENTION]

sorry, correct path is /dev/block/zram0

-a switch seems not to exist in toybox version of swapoff

(so command is swapoff /dev/block/zram0)

you can check with `free` afterwards
[Nexus 7 Android Development] adstraylight:
Deleted
[Nexus 7 Android Development] Ahkah:
That was also my assumption. Later I remembered that the background had not been provided by a static .png file, but by an app called "Einfarbiger Hintergrund" (~ "solid colour background") and was selected as "Live Wallpaper". To avoid further "blackification" I installed a simple paint program, created a solid colour image and selected that one as background image. Finally I deinstalled the live wallpaper app as no longer needed.

If I had written Android I would have provided a "solid colour" background instead of "no background" which in fact just uses black, but, however, manually creating a background image is an acceptable workaround.
[Nexus 7 Android Development] gmikhail:
It looks like the problem is with the ROM. If you find a solution, please write in this thread. I still have not been able to identify the specific cause of the bug.
[Nexus 7 Android Development] adstraylight:
If a reboot fixes it, then the likely cause is either the RAM being full, or the Swap Partition being full, as both of these are reset by a reboot.

It sounds like the Swap to me. I counteract this on the UA ROM by setting the following values for swap in the virtual memory tab of KA:

Swappiness 70

Dirty background ratio 9

Dirty ratio 26

Disksize 200.

I also use a taskiller to root kill (fc) unnecessary apps when the screen is off. The only one ive found to effectively do this is this one: https://play.google.com/store/apps/details?id=com.rhythm.hexise.task&hl=en_GB

I know this ROM is different, but nevertheless this might help...
[Nexus 7 Android Development] gmikhail:
I do not think that this is the case. I can run a bunch of applications and they will be loaded / unloaded without problems. But after some time (~ 1 day) everything starts to slow very much even if there are no open applications. Even the sound stutters and plays at different speeds.

But if the matter is in the swap partition then this is still a bug of ROM. As already mentioned above - in earlier versions of this was not. Perhaps this is a memory leak in internal services. In this case, the swap partition really will not have time to clear.

In any case, thanks for the help.
[Nexus 7 Android Development] vetzki:
[MENTION=6699143]gmikhail[/MENTION]

- like mentioned above, dont use zram and/or ksm

- dont use gapps. Install fdroid and use apps from there

- switch from intellsomething to interactive govenor (lower go_hispeed_load and go_maxspeed_load tuneables)

- if you have root, maybe do a `vdc fstrim dotrim` command occasionally (shouldnt not be necessary but do it maybe once in a week to ensure fstrim ran [you can check with logcat | grep Trimmed] ). Dont trim to often as your device should do it regularly by itself

sorry for bad english

edit:

also could help to find the issue:

save a "uptime && echo "#################" && echo && dumpsys meminfo" to sdcard after reboot (after short time of usage)

and when device starts to get laggy
[Nexus 7 Android Development] adstraylight:
You can check the status of the swap partition by either using the free command in terminal, or via an app like diskinfo. Why not experiment and contribute to the solution? It's the XDA way!?

Edit: btw, the swap values I use are not arbitary, they're tuned to cause the system to gently refresh the partition as it is needed, rather than allowing it to fill completely. Even when apps are unloaded, the system saves data relating to their last used state to the zram rather than saving it to the sd, this helps our groupers as they have terrible io speeds, as utilising RAM is far quicker, for reloading perviously closed apps.
[Nexus 7 Android Development] gmikhail:
Thank you all for your answers. I'm still testing and trying to determine the cause of the lag. As I said, it manifests itself ~ once a day. I can not control when it appears.
[Nexus 7 Android Development] Troublicious:
I tried the tricks given by paasoares and it seems to work great:

- deactivate wifi when grouper is at sleep (Set to Never)

And

- limit background process to at most 4 processes (in dev options)
[Nexus 7 Android Development] Alex_Lyt:
Battery goes crazy )))
[Nexus 7 Android Development] adstraylight:
I'd interpret that as something crashing the system with the CPU running at high frequency, the device being stuck that way until it automatically reboots. Twice.

During the crashed periods, it looks like no battery stats were recorded.

As I say, that's what I'd make of it....else your battery is dying...
[Nexus 7 Android Development] Alex_Lyt:
Before that battery "wasn't discharging" for a few hours of usage. It was 100% )))

I guess, battery is not calibrating... Plus smth is crashing a system
[Nexus 7 Android Development] adstraylight:
Yes, I've had occasional times when the battery miraculously look's like it will last forever ? This is usually resolved by a couple of charge cycles.
[Nexus 7 Android Development] DumF0rGaming:
If you guys trying to kill unnecessary apps while screen is off - try PowerNap Xposed module, your battery will appretiate it as well
[Nexus 7 Android Development] adstraylight:
The point is to unload them from RAM entirely, to maximize available RAM on resume. This can also help free up Zram space also.

My approach has been to finely balance system resources to give as even and stable a UX as possible. The balance can be very easily upset on such a resource limited device especially with the Io lag inherent in the hardware, not to mention the lack of RAM. What I would give for an extra GB!?
[Nexus 7 Android Development] Ahkah:
speaker died?

Last week I installed the "Speaker Boost" app which worked fine with about ~116 percent volume. One evening I shut down the device, and as everytime it rebooted instead, so that I had to shutdown it once more. After restart the next day the sound from the speaker was extremely low and totally distorted (not only for media, but also for alarm etc.).

I deinstalled the "Speaker Boost" app and rebooted the device, but speaker output remains unusable (while headphone works fine).

It might be possible that the Boost app finally damaged the loudspeaker, but why did this happen while the device was switched off and not during operation? Or is there any setting that got corrupted and can be reset via adb or similar?
[Nexus 7 Android Development] AndDiSa:
[MENTION=6699143]gmikhail[/MENTION] well swap space is beeing used as a kind of "memory extension", i.e. it's managed like normal ram and as "free memory is wasted memory" it's freed only when there is a more important process requesting more memory or you are killing the process which is usually the occupied memory. From that point of view there is no guarantee that swap is freed.
[Nexus 7 Android Development] 123x:
Why would you want to replace the battery when it's plugged in all the time anyway?
[Nexus 7 Android Development] -=CRANK=-:
Do you have plans to port Oreo?
[Nexus 7 Android Development] adstraylight:
I agree that keeping as much loaded in RAM is favourable to speed of the apps that are already loaded, the problems come when the system is trying to clear space and load new content simultaneously. I refer to what this article talks about in its last section: https://xdaforums.com/android/general/guide-comprehensive-guide-to-kernels-t3121088

I know it is talking about cache rather than zram, but I've found the same principles apply. This is what led me to start playing with the VM values in the first place, as I too was noticing a slowdown of ui performance once the zram was full.

As I said earlier, it's a case of balance, in this case when to make best use of CPU cycles to prevent noticeable lag\lockups. Ie, we simply don't have the overhead to play with on the grouper with all the demands of a modern ui and os, and so must make more efficient use of what free CPU time we have, without subjecting the system to a continuous stress test.
[Nexus 7 Android Development] gmikhail:
[MENTION=2188693]AndDiSa[/MENTION] Yes, I know that free memory is useless if not used. But the problem is that the swap and RAM are not released when necessary.
[Nexus 7 Android Development] AndDiSa:
[MENTION=8338974]Adst[/MENTION]rylight I agree fully, but you need to differentiate between swap and zram. Swap is memory swapped out to external storage, zram is memory stored ram, but in a compressed way. I.e. compressing takes some time but accessing it is almost as fast as accessing 'normal' ram.

In addition there is no automatism that memory which is located in swap/zram automatically is moved to uncompressed ram when there is enough ram free. In contrary it's even better if it's kept in zram as in that case newly loaded applications can be started immediately without primary compressing / moving / killing other applications.

The only chance you have to control zram allocation / management is using 'swappiness' which defines a kind of measurement whether to kill applications to free memory or to compress memory to put into zram. But if (part of) the memory used by an application is moved to zram there is (almost) no way back ... beside the application is killed and restarted.
[Nexus 7 Android Development] adstraylight:
[MENTION=2188693]AndDiSa[/MENTION], I understand that, but for some reason the values I'm using for VM seem to be regulating the use better than before. I'm not trying to prove anyone wrong, but just report what I've found, and am totally open to discovering that I've made a wrong assumption btw. I do however urge you to read what the OP of the thread I linked says about Dirty Ratio & Dirty Background Ratio.

I recall playing with these had a significant effect on performance and the rate the zram filled up\was freed, hence I arrived at my specific values. The swappiness value I came to as it gives a reasonable balance between fore\background tasks for the CPU to allow for a generally smooth UX.

Edit: while I've got you, maybe you can answer something, do you know why the cache partition of the internal storage isn't used by 7.x ROMs?
[Nexus 7 Android Development] Troublicious:
I can confirm the heavy lags still happens, even with 4 proeess limit …

This problem doesn't exist in first builds, you never had the problem AndDiSa ? ?
[Nexus 7 Android Development] Pumpk1in:
Hi, am I the only one with the slowest wifi speed on earth ?

I never had this problem with my grouper nexus 7 before this ROM. Actually It takes forever to install any apps from Google Play Store :/
[Nexus 7 Android Development] vetzki:
no wifi finally works for me for days without disconnect.

[MENTION=2583740]adstraylight[/MENTION]

regarding /cache. Cache was never used for the cache of apps (thats in /data). /cache is for e.g. ota updates (dont know if it has another purpose on "stock" devices).
[Nexus 7 Android Development] adstraylight:
Thanks, I must have simply not noticed before...

Edit: I'm sure the usage used to fluctuate a bit on M though, now it's just static...
[Nexus 7 Android Development] 1di9:
hi guys

I tried to install this rom (latest 20171111) on my Nexus 7 tilapia following carefully instructions but, after first reboot, I wasn't able to quit from first setup because of setup app closes continuosly after I've choosen not to copy settings from other device or account and starting as a new device.....

Is there any tip or tricks to quit this loop?
[Nexus 7 Android Development] DumF0rGaming:
A few pages ago
[Nexus 7 Android Development] 1di9:
Sorry, I missed those messages......

However, I've already done what is suggested in #2017 and I wasn't able to pull down quick settings to activate wifi as said in #2015

I'll try once again, may be I've forgotten something...
[Nexus 7 Android Development] HeikoE:
A while ago I learned, that the setup assistant can be canceled by tapping the four corners clockwise, starting from top left.

Do that after selecting the language. Then setup wifi. Playstore will ask for an account upon start.
[Nexus 7 Android Development] 1di9:
I succeed in correctly installing this ROM following letterally instructions as in message #2017. May be previously I've made some mistake in that sequence....it seems to work smoothly, execpt for host mtp error that seems to be a common bug. I don't find a way to disable this feature....

However, thanks for support.?
[Nexus 7 Android Development] AirOne70:
[MENTION=2188693]AndDiSa[/MENTION] Here is what your users may be looking for: https://github.com/AirOne70/android_device_asus_grouper-1/blob/du/patchs/frameworks_base.patch (the 2nd part, of course).

Thanks to daniel_hk for this fix.
[Nexus 7 Android Development] goran_s:
I had "mtp error" with previous install but all is ok now. I think I tried to install gapps without reboot after installing ROM and that caused the problem. Last time I installed everything with reboots between and no MTP error. But I do experience lag after some time and there were couple of reboots, most when watching movies in MX player.

best regards,

Goran
[Nexus 7 Android Development] tpuserhp:
​

Glad to hear that substratum is working for you. Agree life and work are more important than tinkering with handsets. I have a bit more time as I'm retired now. :)
[Nexus 7 Android Development] vetzki:
today I encountered a weird bug, battery showed 95% left, suddenly the screen turned black, with no device reaction at all. Put it on charger and after 10-15 minutes finally charging symbol shows up again (with empty battery)

Also I want to mention that I dont have these strange slowdown issues after 1 day usage, so people who have them should really try to drop gapps.

(If you have a rooted phone you still can use apps from play store which dont requiere play services. just copy the base.apk from /data/app and install manually)

edit:

battery section in settings also dont show decrease of battery life
[Nexus 7 Android Development] breaktheblock:
Hi guys,

I have not used my flashed grouper for a while, it went wrong so I decided to flash the latest ROM.

My question is why can't I search for system updates manually when going into settings > about tablet? Is this a global change by Google introduced in 7.0 and above?
[Nexus 7 Android Development] 123x:
That only works with official ROMs.
[Nexus 7 Android Development] minhducsun2002:
No, actually, maybe the ROM's creator has omitted the option (if there's no OTA, why would you need that option?). Besides, any update for this ROM can be flashed through TWRP, so there's no point using system automatic updates.
[Nexus 7 Android Development] minhducsun2002:
I'm a bit confused. Why does the kernel version in Settings > About tablet showing the 3.1.10 version?

Since my other Lollipop device has 3.10.72, it would make some conflicts here...
[Nexus 7 Android Development] vetzki:
Because 3.1 is the kernel version for the nexus7

(google never released a more recent version of the kernel. I think they never did for any nexus device, they always stay at the same version. But it dont really matters which kernel version your using. On pc e.g. centos had kernel 2.6.32 in their 04/2017 release)
[Nexus 7 Android Development] dark0shark:
Just a side note: TWRP has been updated to version 3.2.0.0. Download at

https://dl.twrp.me/grouper/

https://dl.twrp.me/tilapia/

I used Official TWRP App from Play Store to successfully flash recovery on my Nexus 7 (2012) WiFi.
[Nexus 7 Android Development] 123x:
You're right, I simplified. The ROM developer would have to set up an update server and point to that. Hardly any do (why would they), so it usually only works with the official ROMs. The only non-vendor ROMs I know that support OTA updates are the official Lineage OS ROMs, because they have an update server.
[Nexus 7 Android Development] minhducsun2002:
Me too over here. Although, having to use an external browser just to download is a bit more time.
[Nexus 7 Android Development] Ahkah:
The answer " That only works with official ROMs." is only partially correct. Just think about what happens if your device is looking for a new system version. It has to contact a server and has to ask it if there is any newer than the installed one. Such server indeed does exist for official system releases, and it's provided by Google or the device manufacturer (e.g. Motorola), and it exists for some alternative systems like LineageOS and others. But for many "home made" systems there is none. So if you want to have "OTA" (in fact there is no "air" needed....), you might donate some money to AndDiSa, and he (or she or it...) might spend it for a system update infrastructure. :)

Howerver, manual update is relatively painless and reliable, if you just follow the described procedure.
[Nexus 7 Android Development] rafapoza:
Android Oreo (Go version)

do you think this new lite Android version could be possible make it run in our tablet?
[Nexus 7 Android Development] TureX:
Is possible run Google assistant?
[Nexus 7 Android Development] AndDiSa:
I am running Google assistant without any problems since ages ... ;)
[Nexus 7 Android Development] TureX:
How, i cant enable
[Nexus 7 Android Development] AndDiSa:
Settings -> Google -> Search -> Settings

(names may be different as I translated from German)
[Nexus 7 Android Development] Danielmariuss:
How does this ROM go on Nexus 7 TILAPIA? Is it ok on 3G?

Thank you
[Nexus 7 Android Development] Flounderist:
Kernel building tips

Hi [MENTION=2188693]AndDiSa[/MENTION], I'd like to start some kernel building using Xubuntu 16.04 on a VM.

I already cloned your sources and GCC 4.8 toolchain, but I am stuck at building, getting several error messagges depending of the building guide used.

Do you have any suggestion? I am super noob in Linux :o

Thanks in advance.
[Nexus 7 Android Development] AndDiSa:
[MENTION=7193743]Flounderist[/MENTION] I am using Ubuntu 16.04 for building, too, but without knowing the concrete error messages it's difficult to suggest s solution for your issues. Most likely one or more packages on your system needs to be upgraded to get the build process running.
[Nexus 7 Android Development] vetzki:
[MENTION=7193743]Flounderist[/MENTION]

what is/are the error message/s ?

edit: already asked
[Nexus 7 Android Development] Flounderist:
Last time I completed menuconfig process but I had error 2 after command make -j2 ARCH=arm.
[Nexus 7 Android Development] AndDiSa:
[MENTION=7193743]Flounderist[/MENTION] generally I do not build the kernel as standalone, but integrated with the ROM. For that there is an additional kernel make file in the build project. The error 2 message I do see also within my builds but it doesn't harm ...
[Nexus 7 Android Development] Zulliz:
I tried installing this today,it runs smooth and all but diskinfo still shows my device as using ext4 and not f2fs why is that?
[Nexus 7 Android Development] Alex_Lyt:
You need to change fs manually
[Nexus 7 Android Development] FirePsych:
I think system is ext4. Data and cache can be f2fs.

When you reformat to f2fs, you will lose your data.

Someone correct me if I'm wrong.
[Nexus 7 Android Development] Flounderist:
Kernel compiled

After some googling I succeded to compile :D

Below the command list. The terminal has been opened in the kernel folder:

#!/bin/bash

export ARCH=arm

export CROSS_COMPILE=/home/android/meatball/arm-eabi-4.8/bin/arm-eabi-

mkdir output

make clean && make mrproper

make -C $(pwd) O=output tegra3_android_defconfig

make -j2 -C $(pwd) O=output

I had 2 files in output: Image (10.6M) and zImage (4.9M).

I'd like to test zImage using Anykernel2. Do I need to add some files or zImage is enough?
[Nexus 7 Android Development] AndDiSa:
[MENTION=7193743]Flounderist[/MENTION] well I don't know well anykernel, but the zImage binary you have created is the kernel only part, i.e. to get a functional boot image you need to add the ramdisk part.
[Nexus 7 Android Development] AndDiSa:
Version with December security fixes (2017/12/05)

Today I've uploaded a new version of the ROM (Grouper / Tilapia) containing the December security fixes. You can download them from the OP. As Google has updated the 7.1.2_r28 devices to 7.1.2_r36 I compared the backported cherry picks and added some missing commits to this ROM, too. Beside that no bigger modifications only increasing ramdisk size to 250mb again as 200mb is not enough to keep all important processes in memory and decreasing swappiness a bit.

If you are familiar with the updating process, you can download the new versions also from here: Grouper OTA 20171208 / Tilapia OTA 20171208

And as always: flash on your own risk ...
[Nexus 7 Android Development] Flounderist:
May I get ramdisk unpacking a boot.img file from a LOS or AOSP builds? I am currently running last aaopt LOS 14.1 unofficial build.
[Nexus 7 Android Development] AndDiSa:
[MENTION=7193743]Flounderist[/MENTION] As I told you already, I didn't use anykernel yet, but generally you should be able to extract all needed files from the boot.img. I suppose the version from aaopt will work, too, but without guarantee ... ;)
[Nexus 7 Android Development] MicheleFrost:
Same here.

Inviato dal mio Mi A1 utilizzando Tapatalk

---------- Post added at 05:08 PM ---------- Previous post was at 05:04 PM ----------

Hi, What do you think about Android Go? Will It bring new life to our Nexus 7 too?

Inviato dal mio Mi A1 utilizzando Tapatalk
[Nexus 7 Android Development] basuraunak:
lets hope it does, found this device lying around, still in perfect shape. If it is usable might as well use as a media device :fingers-crossed:
[Nexus 7 Android Development] 239:
The new and also the previous build are much better regarding smoothness and battery life. Had quite heavy lags as many users reported with earlier versions, will see how it runs with full memory/swap after some days uptime.

It's a joy to use the tablet again, your effort is greatly appreciated!
[Nexus 7 Android Development] ul71m0:
Hi i installed rom and gapps from first post, but gapps are missing after boot. I went into TWRP again and flashed again gapps but again they are not showing, and no error message during install, i tried open gapps nano and pico but they cannot be installed due to lack of space... What else can i try?
[Nexus 7 Android Development] AndDiSa:
Which TWRP version do you use?