High IOWAIT - Nexus 7 Q&A, Help & Troubleshooting

The issue started when rotating my Nexus 7 from portrait to landscape mode. I have the lcd_density set to 177, so the homescreen rotates. Today, the homescreen icons started disappearing for 20-30 seconds when rotating. I enabled "Show CPU Usage" in the Developer Options, and noticed that the IOWAIT (blue bar) is really freaking high whenever I rotate. So I connected through ADB, and ran TOP. IOWAIT was shown between 33% and 77% right after rotating.
So I ran "
Code:
echo 1 > /proc/sys/vm/block_dump ; cat /proc/kmsg
" to view what was causing the iowaits. It appears that "launcher-loader" is writing a ton of data.
I am out of ideas of what to do. Anyone have suggestions?

Don't use the dpi change. Just use paranoid android for proper tablet mode.
Sent from my LG-P999 using xda app-developers app

redmonke255 said:
Don't use the dpi change. Just use paranoid android for proper tablet mode.
Sent from my LG-P999 using xda app-developers app
Click to expand...
Click to collapse
I don't think the LCD Density is the cause of the IOWAIT. I have been using it at 177 DPI for months.

Maybe it's related to the LAG issue? How much do u have in storage?
I met same and turned out IO performance so poor due to low storage (<3G)

merrywhq said:
Maybe it's related to the LAG issue? How much do u have in storage?
I met same and turned out IO performance so poor due to low storage (<3G)
Click to expand...
Click to collapse
You know, it did get slow once I went under 3 gigs free. However, I have now deleted stuff, and it is back up to 4.7 free, and IOWAIT is still high.
EDIT: I installed the Franco kernel, hoping that would fix the lag issue, but it did not. I am starting to wonder if the flash memory is going bad.

cmbeid said:
You know, it did get slow once I went under 3 gigs free. However, I have now deleted stuff, and it is back up to 4.7 free, and IOWAIT is still high.
EDIT: I installed the Franco kernel, hoping that would fix the lag issue, but it did not. I am starting to wonder if the flash memory is going bad.
Click to expand...
Click to collapse
if you check the LAG thread, you should find once you get below 3G free, it WON'T come back even you free some space, a factory reset does work however.

merrywhq said:
if you check the LAG thread, you should find once you get below 3G free, it WON'T come back even you free some space, a factory reset does work however.
Click to expand...
Click to collapse
Crap. That does not make any sense!
Thanks though, I read through a few pages of the LAG thread, but at 48 pages long it is a lot to catch up on.

Google is already investigating this. Maybe there will be a fix...

cmbeid said:
You know, it did get slow once I went under 3 gigs free. However, I have now deleted stuff, and it is back up to 4.7 free, and IOWAIT is still high.
EDIT: I installed the Franco kernel, hoping that would fix the lag issue, but it did not. I am starting to wonder if the flash memory is going bad.
Click to expand...
Click to collapse
Did u disable fsync?
Installing Franco kernel by itself won't fix the issue. U need to install then disable fsync using the Franco kernel app or a script.

dwang said:
Did u disable fsync?
Installing Franco kernel by itself won't fix the issue. U need to install then disable fsync using the Franco kernel app or a script.
Click to expand...
Click to collapse
Hmm, the kernel said it was disabled by default, so I didn't even bother to check. Lag issue fixed. Just am afraid about this data integrity issue... oh well.

cmbeid said:
Hmm, the kernel said it was disabled by default, so I didn't even bother to check. Lag issue fixed. Just am afraid about this data integrity issue... oh well.
Click to expand...
Click to collapse
It used to be disabled by default, but was changed in a future update to be enabled by default. Can be disabled with a script:
Code:
#!/system/bin/sh
echo N > /sys/module/sync/parameters/fsync_enabled

espionage724 said:
It used to be disabled by default, but was changed in a future update to be enabled by default. Can be disabled with a script:
Code:
#!/system/bin/sh
echo N > /sys/module/sync/parameters/fsync_enabled
Click to expand...
Click to collapse
I ended up just doing it through ADB to test. It feels good to finally have a fast tablet again.

Related

32Bit Color depth reg hack on Focus

Tried the reg keys here (in post #6). Couldn't find a combination of values that didn't cause very irritating laggy home screen scrolling isuues.
Anyone get this working to his/her liking on a Focus?
I'm using bpp 32 PanelBPP 24 PrimBPP 32
I have a tiny bit of lag on occasion, but it's worth it for me
jmerrey said:
I'm using bpp 32 PanelBPP 24 PrimBPP 32
I have a tiny bit of lag on occasion, but it's worth it for me
Click to expand...
Click to collapse
Yeah, colors are MUCH better. But the scrolling lag sucks, as the fluidity is one of the major assets of the OS. I guess it's just a consequence of using last-gen hardware...
I can't even find those keys... hmmm....
thealanshow said:
I can't even find those keys... hmmm....
Click to expand...
Click to collapse
They don't exist on the Focus out of the box. You've got to create them.
Sucks that our phones can't handle the 32bit color and remain fluid.
Is 24bit color selectable, and if so does that yield better performance?
Sent from my Transformer TF101 using XDA Premium App
Yes just put 24 instead of 32 win you add the key. Dword=24
Sent from my SGH-i917 using XDA Windows Phone 7 App
I was using this with all values set to 32 on my Focus and didnt have any issues whatsoever with lag. ....But, i did have another wierd issue come up:
http://forum.xda-developers.com/showpost.php?p=14323276&postcount=546
so im not using this tweak anymore.
Anyone else having GPS issues?
GPS worked fine but I have had the "Red Screen of Death" pop up and found from another thread that those who had it removed the 32bit hack and it went away.
I just pull the battery and reboot and am usually fine.
hx4700 Killer said:
GPS worked fine but I have had the "Red Screen of Death" pop up and found from another thread that those who had it removed the 32bit hack and it went away.
I just pull the battery and reboot and am usually fine.
Click to expand...
Click to collapse
Wow... It makes no sense whatsoever but it certainly affects my GPS. Wish I were wrong. The red screen doesn't concern me really. It happens time to time but just holding the power button until it shuts off and restarting fixes it. Same as a battery pull really.
benjammin said:
I was using this with all values set to 32 on my Focus and didnt have any issues whatsoever with lag. ....But, i did have another wierd issue come up:
http://forum.xda-developers.com/showpost.php?p=14323276&postcount=546
so im not using this tweak anymore.
Anyone else having GPS issues?
Click to expand...
Click to collapse
just out of curiosity, how did you stop using the tweak?
munkeyphyst said:
just out of curiosity, how did you stop using the tweak?
Click to expand...
Click to collapse
Just deleted the three values I added: bpp, PanelBPP, PrimBPP.
Wow, didn't know about this fix. Just added the values and restarted. Things look very nice, the banding is gone, and I do not notice lag (as of yet). Hope it stays working this nicely...very impressed with this fix. *Also, just checked Gmaps to see if it could locate me through GPS and it found me perfectly. Not sure if it's just me, but the fix seems to work perfectly.

System Killing Launcher on every app launch!!

Hi!! I have a problem, I'm currently Running Darky's 10.1 with dark core 2.6... Everything is smooth and snappy, however the system keeps killing my launcher everytime I launch an application whether it be a game, browser, news app... Whenever I exit the app the launcher reloads and it makes the phone really really slow and laggy for 10-15 seconds...
I currently using ZEAM launcher, not sure whats causing this, i've been using this launcher since its launch and only had this problem when i was on stock froyo...
Any ideas what can be done to fix this issue...
Thanks!!
Same problem here.
I am on GigerReal 7.1.3 and the worse thing is when it you try to make a phone call and the bloody thing just restarts the phone every third key pressed.
I can only call using voice calling when this happens...
I am using LauncherPro but it also happens in Ginger Launcher and TW Launcher 4.5
Just out of interest guys, how much free memory is showing for you in Settings > Applications > Running Services ?
I am running stock JVQ and although the phone works fine after initial boot (with around 180mb free) this number seems to drop over time and results in any new application clearing any other app from the memory. This even meant that if I got a text message while using the web browser and replied to it, by the time I went to return to the browser it had to reload where I was from scratch. It was also clear that after playing a game and returning to the home screen, even this was having to reload and "redraw" again.
That in itself is a minor annoyance but eventually it seemed to get so bogged down the whole system froze with the "black screen of death" and I had to do a forced reboot. I'm aware, of course, that JVQ is not an official release so it's not fair to be too harsh on Samsung here...
I seem to have a lot of memory free. It happens after the phone has been up for some time.
I noticed that launcher pro was reloading the widgets every time it starts. Also i seem to notice that it happens when you dial a couple of numbers and it starts giving you suggestions from the contacts. So it could be contact related?
Tepes4 said:
I seem to have a lot of memory free. It happens after the phone has been up for some time.
I noticed that launcher pro was reloading the widgets every time it starts. Also i seem to notice that it happens when you dial a couple of numbers and it starts giving you suggestions from the contacts. So it could be contact related?
Click to expand...
Click to collapse
This is the same that happens on my system... The launcher just reloads all the widgets everytime I close an application... the amount of ram is always close to 243/337.. So its close to 90-100 mb free, which is enough i suppose... Still the launcher just reloads everytime an app is closed... Its really getting annoying...
basicly you must set HOME_APP_ADJ to 0 making home app unkillable =)
am not sure but probably do that
/data/local.prop -> add such line ro.HOME_APP_ADJ=0
and restart - have not tested just pure theory (the .prop location)
$omator said:
basicly you must set HOME_APP_ADJ to 0 making home app unkillable =)
am not sure but probably do that
/data/local.prop -> add such line ro.HOME_APP_ADJ=0
and restart - have not tested just pure theory (the .prop location)
Click to expand...
Click to collapse
Actually, putting the value as 1 worked better for me. My launcher so far has not been killed even once.
ya 1 should work flawlesly
0 is making it bulletproof/unkillable at any state
but 1 should be safest value
I think Spare Parts allows you to adjust the task killer's sensitivity. Maybe have a play with that and relax the settings.
$omator said:
ya 1 should work flawlesly
0 is making it bulletproof/unkillable at any state
but 1 should be safest value
Click to expand...
Click to collapse
Hi Thanks for the advice, however i'm not sure how to set these values, Is there any tool that I can use to do that??
psyren said:
I think Spare Parts allows you to adjust the task killer's sensitivity. Maybe have a play with that and relax the settings.
Click to expand...
Click to collapse
spare parts at least free one does not have such option
also this is not about adjusting memory taskkiller options
not the one that you can setup with this useless juwe script for example
different thing
exjc1986 said:
Hi Thanks for the advice, however i'm not sure how to set these values, Is there any tool that I can use to do that??
Click to expand...
Click to collapse
never came across one
exjc1986 said:
Hi Thanks for the advice, however i'm not sure how to set these values, Is there any tool that I can use to do that??
Click to expand...
Click to collapse
Attached is an APK which adds that line. Make sure you're rooted first. I wrote it in the past 10 minutes, so it's very simple and might crash, but it did work for me.
Just install it, launch it, confirm root and then watch out for a small message. If successful it will directly ask you to uninstall it. Reboot, and done.
there is also ro.HOME_APP_MEM that can be changed to 4096
to follow other oom_adj=1 settings =)
@martino2k6
Thanks a lot dude... The apk installed perfectly... I'm already seeing improved performance from my device... The launcher hasn't been killed once since the install...
Thanks again for all your help... appreciate it...
Sent from my GT-I9000 using XDA App
http://androidnexus.com/guides/fix-home-screen-redraw-lag-in-launcherpro-and-adw-launcher
Try changing the lowmemoty killer setting to something less aggressive. Your phone is trying to keep too much free memory so has to kill off apps.
Download Galaxy Tuner (using memory manaber option)and set the application cache values to the new samsung default as follows:-
fa=10 MB
va=16 MB
ss=20 MB
ha=24 MB
cp=28 MB
ea=32 MB
Make a note of your current settings in case it doesnt help.
You can also use Galaxy Tuner to set JEWE's file system cache
, settings are:-
SWP: 50
VCP: 10
DEC: 5
DWC: 10
DRA: 90
DBR: 5
These work well for me so give them a whirl, you can always put the values back to where they are now.
mate the problem is solved already - please read dont spam those juwe crappy values ok ?
Ok, cool
Sent using geek power
I cannot thank you enough mate!
There were times i could make a phonecall cause it kept bringing me back to the home screen!
You sir, are a gentleman and a scholar!
martino2k6 said:
Attached is an APK which adds that line. Make sure you're rooted first. I wrote it in the past 10 minutes, so it's very simple and might crash, but it did work for me.
Just install it, launch it, confirm root and then watch out for a small message. If successful it will directly ask you to uninstall it. Reboot, and done.
Click to expand...
Click to collapse
exjc1986 said:
@martino2k6
Thanks a lot dude... The apk installed perfectly... I'm already seeing improved performance from my device... The launcher hasn't been killed once since the install...
Thanks again for all your help... appreciate it...
Sent from my GT-I9000 using XDA App
Click to expand...
Click to collapse
Tepes4 said:
I cannot thank you enough mate!
There were times i could make a phonecall cause it kept bringing me back to the home screen!
You sir, are a gentleman and a scholar!
Click to expand...
Click to collapse
You're both welcome. That's what [helping out] XDA is for after all

[Q] issue with app closing (not FC)

Hey everyone
using a atrix 4g
at&t branded unlocked on rogers
running cm7 (CM7 official nightly) using faux123 kernel 1.45ghz
i'm having an interesting issue here... and im not sure how to resolve it, hence why i am make this thread.. i have searched and havent found anything
I use an app call issimo (twitter) now when you open it, it loads the timeline as usual you can do whatever...
my issues is after a certain amount of time, (its random) i try to go back into the app and its like i have never opened it... eg has to load the timeline again and isnt where i left it when i backed out...
it runs in the background just fine, its just there are certain times it does that...
i have set my heap size to 48mbs, and such but nothing is solving this...
the dev seems to think its related to the ROM needing more memory so it just closes the app... and like i said its not force closing... just exits itself.
how can i stop this from happening? anyone have any ideas?
thanks!
Try setting heapsize to 64 mb. Also have u used or has someone else used an app that messes with minfree values, or anything else that may adjust how much memory to keep/ free up?
Sent from my MB860 using Tapatalk
Phalanx7621 said:
Try setting heapsize to 64 mb. Also have u used or has someone else used an app that messes with minfree values, or anything else that may adjust how much memory to keep/ free up?
Sent from my MB860 using Tapatalk
Click to expand...
Click to collapse
i have previously set the heap to 64 and the dev said to not as i was having issues with it lagging due to to much in the heap... (idk...)
as for the minfree values and etc you mentioned... i dont think so... honestly i'm still fairly new to the android and the hacking/modding... that being said the minfree value is a new term for me and i dont know what that it, or how to change it lol
thanks for the help so far!

To all people who has the memory managment problem

My Moto G 2014 xt1068 did not perform well for a long time. I tried editing the lmk values with just a little improvement, I also added ro.MAX_HIDDEN_APPS to Build.prop with a value of 16. But with this, the phone tends to work ok until RAM gets full. Then it hangs for a lot of time and the screen goes black. But yesterday, without almost any hope I went to Kernel Adiutor and lowered the Z-RAM to 0. And man, that was awesome. Now my Moto G is another phone. I'm almost sure it's not placebo, because now I can listen to music while I'm navigating on chrome and I have Facebook Messenger chat heads active, and before that was just not possible. So, if you want to give it a try, let me know if it worked for you and I hope I helped!
I'm on Minimal OS with the last update and no kernel added.
Vicioxis said:
My Moto G 2014 xt1068 did not perform well for a long time. I tried editing the lmk values with just a little improvement, I also added ro.MAX_HIDDEN_APPS to Build.prop with a value of 16. But with this, the phone tends to work ok until RAM gets full. Then it hangs for a lot of time and the screen goes black. But yesterday, without almost any hope I went to Kernel Adiutor and lowered the Z-RAM to 0. And man, that was awesome. Now my Moto G is another phone. I'm almost sure it's not placebo, because now I can listen to music while I'm navigating on chrome and I have Facebook Messenger chat heads active, and before that was just not possible. So, if you want to give it a try, let me know if it worked for you and I hope I helped!
I'm on Minimal OS with the last update and no kernel added.
Click to expand...
Click to collapse
That's a strange behaviour: zRAM usually improves the performance of the device. It's used like a swap disk but obviously it has better I/O speeds; on the other hand the workload on the processor is a bit heavier. Just one question: what was your previous zRAM value?
It was at 250mb, the default value.
It's supposed to help if it's enabled but oddly enough, it's not even enabled on some phones. To verify it's even enabled, in terminal emulator type 'free -m', and the swap column has to be non-zero.
Sent from my SM-T530NU using Tapatalk
It seems that helped me too
Tel864 said:
It's supposed to help if it's enabled but oddly enough, it's not even enabled on some phones. To verify it's even enabled, in terminal emulator type 'free -m', and the swap column has to be non-zero.
Sent from my SM-T530NU using Tapatalk
Click to expand...
Click to collapse
I have xt1068 and my default value was 160.After I set it to zero and rebooted I can watch video in chrome and the play music is not closed, only paused.
How do I set it to 0? What options do I have to enable?
Sent from my XT1063 using Tapatalk
Jstbe said:
How do I set it to 0? What options do I have to enable?
Sent from my XT1063 using Tapatalk
Click to expand...
Click to collapse
Normally in the kernel settings with something like kernel adiutor.
the setting won't stick for me in Kernel Adiutor, it keeps resetting back to 160
I tried that out, the setting stays on 0 when you select "apply on boot" and reboot. But in my case it made the multitasking issue even worse, it is much better with the zram setting on 250 which is the default value of my kernel.
Wolfcity said:
I tried that out, the setting stays on 0 when you select "apply on boot" and reboot. But in my case it made the multitasking issue even worse, it is much better with the zram setting on 250 which is the default value of my kernel.
Click to expand...
Click to collapse
As it should. I can't imagine why setting it to zero would help multitaskkng.
Tel864 said:
As it should. I can't imagine why setting it to zero would help multitaskkng.
Click to expand...
Click to collapse
Agree.
Sent from somewhere
Tel864 said:
As it should. I can't imagine why setting it to zero would help multitaskkng.
Click to expand...
Click to collapse
Yes, i changed it to 0 and the performance was worst, launcher resets, lags with camera and chrome.. changed it back to 250 and it was fine!
Tel864 said:
As it should. I can't imagine why setting it to zero would help multitaskkng.
Click to expand...
Click to collapse
Maybe it's just with some ROM's/Kernels, I was obviously not understanding why like you.

How to stop ActivityManager killing apps due to "high power cost"???

By now you may have heard about Axon 7 killing music playing app issue, if you haven't experienced it yourself already. For me I'm having a similar or at least related issue. The phone would kill my game when I turn off and on screen. After some investigation, below is my observation
1. Doesn't happen all the time. After a fresh reboot, no killing for a while... but after some time using the phone, it starts to happen
2. Not app-specific: After playing a game heavily for a while, the killing starts... only for that specific game. If I play a different game, then only that new game gets killed.
This have driven me kinda crazy. A look at adb logs reveals this:
12-22 12:45:34.229 I/ActivityManager( 1752): Killing 23881:jp.co.happyelements.toto/u0a122 (adj 0): excessive high power cost :jp.co.happyelements.toto
What the actual f***??? Why would ZTE kill my "excessive high power cost" process *after* I turn on the screen (and not when I turn off screen, which was 5 seconds earlier)??? Has nobody in ZTE thought about that apps that has "high power cost" may not be actually "excessive" but totally within reasons and fall into the category of normal every day use?
And no amount of changing the native "power saving" options stopped this behavior. Back in the days I remember there was some root/xposed module that would whitelist apps from being killed by the OS but I couldn't remember the name. So now I have to ask help on how to deal with this idiocy.
Edit: My apologies... I just noticed I posted in the wrong section... mods please move the thread to Q&A section if possible. Thanks a lot.
is there seriously no solution?
This is intolerable
Turn off smart power lol. Not rocket science my friends
icenight89 said:
Turn off smart power lol. Not rocket science my friends
Click to expand...
Click to collapse
I did. Didn't help.
If it was that easy, then I wouldne be here asking about it would I?
Yep, have the same problem after trying the same things. Several apps (2 of which I use for monitoring blood sugar levels) will randomly stop updating until either re-launched or the phone is rebooted. I have disabled all power manager options to no avail. Whatever power management system ZTE has implemented, it's FAR too aggressive.
Disclaimer - I haven't pulled logcats, but your description of the problem matches mine exactly. Here's hoping for a fix in Nougat and/or a custom ROM, otherwise I'm moving to a different phone. The A7 has great hardware but the stock software is a bloated mess.
B27 does not have this issue (which is why I downgraded to it). Might be a solution for you until the next upgrade releases.
whoiswes said:
Yep, have the same problem after trying the same things. Several apps (2 of which I use for monitoring blood sugar levels) will randomly stop updating until either re-launched or the phone is rebooted. I have disabled all power manager options to no avail. Whatever power management system ZTE has implemented, it's FAR too aggressive.
Disclaimer - I haven't pulled logcats, but your description of the problem matches mine exactly. Here's hoping for a fix in Nougat and/or a custom ROM, otherwise I'm moving to a different phone. The A7 has great hardware but the stock software is a bloated mess.
Click to expand...
Click to collapse
@whoiswes If you are talking about the xdrip app. I too want this app to work with this phone. I tried CM13 and had the app work for hours then at night it stopped working. I only tried it for one night so didn't try different settings. At least this is a positive sign once CM13 becomes more stable or CM14 is released. I heard the app won't work with B27 either.
Found a solution, though it needs root
Code:
pm disable com.zte.powersavemode
then reboot
This totally disables the power saving menu though
phailyoor said:
Found a solution, though it needs root
then reboot
This totally disables the power saving menu though
Click to expand...
Click to collapse
Can you freeze it with TB?
Actually no that didnt help just made it take longer
I have the same issue, ram management is too aggressive.
phailyoor said:
Found a solution, though it needs root
then reboot
This totally disables the power saving menu though
Click to expand...
Click to collapse
Didn't work
:crying::crying::crying:https://forum.xda-developers.com/axon-7/development/xposed-kill-zte-killer-t3532298
phailyoor said:
:crying::crying::crying:https://forum.xda-developers.com/axon-7/development/xposed-kill-zte-killer-t3532298
Click to expand...
Click to collapse
Did this work?
borijess said:
Did this work?
Click to expand...
Click to collapse
No because it has nothing to do with powermanager.
doyou37 said:
No because it has nothing to do with powermanager.
Click to expand...
Click to collapse
Then why was it posts here?
borijess said:
Then why was it posts here?
Click to expand...
Click to collapse
People are desperate
borijess said:
Did this work?
Click to expand...
Click to collapse
Yes
doyou37 said:
No because it has nothing to do with powermanager.
Click to expand...
Click to collapse
Lol did you even look at it?
doyou37 said:
People are desperate
Click to expand...
Click to collapse
I made this xposed module specifically to fix the problem described in OP. If you have the exact problem, including the logcat message, then the module should fix it.
If you dont have the exact problem, including the logcat mesage, then go ****post in another thread.
My solution is to whitelist all apps in:
settings -> energy management -> app energy management -> option button (upper right) -> app protection list -> option button -> set all to off
But the problem is that this setting resets everytime you install/delete an app
Edit: Ok i just tried out manually setting all apps to "off", now it doesn't reset the apps when installing an app but the new app ist automatically allowed to be cleaned. So you still have to disallow cleaning for each installed app manually.
Just an FYI, I updated to the Cyanogenmod/Lineage 13 Beta by UDev and one of my problem apps has been running for 18 hours without a single hiccup. Trying the second problem app later today. Not a solution for this problem but from my perspective it definitely pinpoints Power Manager as the culprit.
@borijess - yeah, Nightwatch and xDrip are the 2 apps that I've had trouble with, and so far Nightwatch is working great on CM13 (1228 build).

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