Database Users

Increasing readahead in a not completely retarded manner

So...there have been some reports going around on reddit and, here I guess, that increasing readahead will make your sd card faster, and maybe some of you noticed that on my build from early March that I had changed the default readahead values as well. And, the truth is, that it generally does, but the reason the mainline kernel tree doesn't have a higher readahead value isn't because some kernel "developers" here are smarter than Linus and everyone else, but because it is generally a bad idea, and the way some kernel "developers" have implemented it, it is an almost unbelievably stupid way to do it.
So, to give a little background about why the way some people implemented it is a really bad idea...readahead works like this - when you need a section of data from the disk, the kernel will grab that data, and anticipating you'll also use the next X number of kb, it will also grab that data as well and put it into memory. So, when you're doing something like listening to music, or copying data from an sd card (ie long sequential file reads), having a larger readahead is a good thing, and will speed up the process and make things more efficient. But when you aren't doing long sequential reads, you end up thrashing your data. In other words, if you set the readahead value to, let's say 1024kb on /system, every time you access a file you're reading ahead the data that you need, plus and additional 1024kb, or to the end of the file (wouldn't make much sense to read ahead past the end of a file). If you don't end up using that 1024kb it gets flushed from memory, and you read ahead on some other file by 1024kb. You don't end up using that section of data from readahead, it gets flushed, etc, etc. It's a tremendously stupid waste of resources to read ahead that much when you aren't using it. I mean, there's a reason why some of these things are tunable in the kernel and not set to higher values.
And if you want some serious proof check diskstats. With readahead set to 128kb on /system, I still have less than 10% of reads merged. If you only have 10% of reads merged with a 128kb readahead, why on earth (unless you don't know what you're doing) would you want to increase readahead to 1024kb?! To take this one step farther, with readahead set to 4kb, I still only have about 1/3 of the reads merged.
Isn't there a better way to increase readahead?
Yes. The better way is to use Wu Fengguang's series of patches found here http://lwn.net/Articles/372281/. The end result of these patches is that /system, /cache and /dbdata have readahead values of 4kb, /data and your internal and external sd cards have readahead set to 512kb. If you want to take it a step farther and increase it to 1024kb (or whatever value you happen to like - note that you get to a point where you don't get any more throughput, I wouldn't go beyond 1024kb personally), you can do it manually at
Code:
echo XXXX > /sys/devices/platform/s3c-sdhci.0/mmc_host/mmc0/mmc0:0001/block/mmcblk0/queue/read_ahead_kb
(internal) and
Code:
echo XXXX > /sys/devices/platform/s3c-sdhci.2/mmc_host/mmc2/mmc2:bf2e/block/mmcblk1/queue/read_ahead_kb
(external).
What I do is have scripts set up in Gscript lite to increase and decrease readahead, but I don't even use these all the time. Also, if you don't want to flash kernels just to do this, you can set the readahead value for any drive manually, just like for the sd cards,
Code:
echo XX > /sys/devices/virtual/block/stl9/queue/read_ahead_kb
(/system)
Code:
echo XX > /sys/devices/virtual/block/stl10/queue/read_ahead_kb
(/dbdata)
(no point in increasing readahead on /cache, and really, really, really no point in doing it on bml or the other block devices...lol).
In other news...I promise I'll be back soon. I bought a house partially on a whim, partially to spite my girlfriend, and I've been rather busy tweaking the place I live in instead of my phone. But, I just started sorting through the patches I made to my personal sources and I will hopefully have it done tonight...(I know, I've said that many times before, but this time I'm serious...I think)
edit - as an aside, if you've ever wanted to have your display be at the lowered light setting that it switches to just before the screen automagically shuts off, you can control that as well at
Code:
echo 1 > /sys/devices/platform/s3cfb/spi_gpio.3/spi3.0/backlight/s5p_bl/brightness
it doesn't have to be 1, any value from 1-20 seems to have the same brightness, to my eyes at least. Again, I have this set up as a script in Gscript and if I want to dim the display a bit more I run this script...you have to use it every time you unlock the display or if you get close to the screen timeout limit and then touch the screen again.

good read and explanation. thanks

im guessing the new kernel will have the above mentioned readahead mods? cant wait!

Thank you man. This is the only useful description about readahead I've ever read and confirms that kernel default value is not so stupid as it looks.

so, is it a good idea to increase readahead if the only files on the sd card are mp3's, jpeg's and documents?

npt1988 said:
so, is it a good idea to increase readahead if the only files on the sd card are mp3's, jpeg's and documents?
Click to expand...
Click to collapse
Yeh, bigger files that are streamed like movies or music will benefit from a higher read ahead. Smaller files like word docs might not.

[null]

just curious to know. will high readahead kb use more battery?
thanks

Hellboy4 said:
just curious to know. will high readahead kb use more battery?
thanks
Click to expand...
Click to collapse
Better to use 128kb for all existing IO blocks.

how increase read ahead cache and sdcard to 2048 in phoenix os
Hello XDA memebers and admin
i need help and very tired
i dont want use L speed in phoenix os for boost phone and speed read and write
i need other apk or code or tweak
please help me

Thanks for this useful post, which reminds me a few years ago every root user wanted to increase readahead. So I built a tool to actually test and compare read-speed when setting different readahead values.
The tool will read the content of the SD card (external or internal storage) up-to a predefined size (100Mb up-to 1Gb) and show resulting speed for various values of readahead (from 128Kb up-to 5Mb).
On a Nexus 4 running Android 4.2, 128Kb and 256Kb were between 20-50% slower, depending on files being read.
On a S10+ running Android 10 however, gain of increasing read-ahead is not so obvious.
I'd be very much interested in results from other devices running various version of Android.
You can get the tool here, and get support here.

VM HEAP, Swap, and games

If I understand this correctly, the largest amount of RAM an app can use is determined by the VM Heap size. If my heap size is 32MB, no program can use more than 32MB.
SWAP will write a app out of RAM to a swap partition instead of closing the program. This is helpful for having more programs "active" so if I want to switch back to a program, it just resumes by loading the swap back to RAM, instead of having to restart the application.
So, I can increase the VM Heap size and it could improve a game's performance by allowing it to have a larger memory footprint. SWAP will not help improve a games performance, but if I switch out of a game, it will make it easier to return to since it may not have to reload it.
Do I have this correct?
Is there anything else I can do to improve a high-end game performance other than overclocking?
Also, does SWAP provide any other benefits other than not having to reload an application? Maybe better memory management or something.
Also, what is the max read/write speed of the GT540? Could it max out a class 10 SD card?

[Q] MyTouch 3G (Saphire) 32B with Ginger Yoshi 1.2 Questions

I'm Running Ginger Yoshi 1.2 and I'm still seeing a lot of lag with the dialer/phone (Takes too long to load and most of the time doesn't load the custom ring tone for that contact), also the following games lag and they where not lagging on the stock ROM (1.6 from T-Mobile)
Blow Up (Lite)
Bubble Buster Smileys
Regarding Performance Settings, I have the following questions:
What would be the best setting for CompCahce? I've read that it's recommended for this type of phone, would 26% be OK?
I have JIT Disabled since I've read it still very much unstable and might cause other things to fail, like the screen off/on animations, is this correct?
I have Disabled Surface Dithering, Is it worth enabling it?
I have enabled Allow Purging of assets, I've read that this really helps with the RAM limitation of this phone, is this correct?
I don't have Home or Messaging locked, are they worth locking?
Lastly, I have VM Heap size to 32M, is this the best for my Phone?
I've searched and haven't found anything clear enough for me regarding these questions, if they are answered somewhere just give me the link to the post.
Thank you all for your help and a Huge Thanks for Team Yoshi for there excellent ROM.

I flashed Ginger Yoshi 1.2 recently. I have a question for you. I am unable to get Wifi Tethering working with the same phone. Is it working for you?

I don't use Wifi Tethering
Sorry I don't use it since I don't have a Data Plan...

Quasi-Detailed Reply to YoshiMod Settings
ElConedeTJ said:
I'm Running Ginger Yoshi 1.2 and I'm still seeing a lot of lag with the dialer/phone (Takes too long to load and most of the time doesn't load the custom ring tone for that contact), also the following games lag and they where not lagging on the stock ROM (1.6 from T-Mobile)
Blow Up (Lite)
Bubble Buster Smileys
Regarding Performance Settings, I have the following questions:
What would be the best setting for CompCahce? I've read that it's recommended for this type of phone, would 26% be OK?
I have JIT Disabled since I've read it still very much unstable and might cause other things to fail, like the screen off/on animations, is this correct?
I have Disabled Surface Dithering, Is it worth enabling it?
I have enabled Allow Purging of assets, I've read that this really helps with the RAM limitation of this phone, is this correct?
I don't have Home or Messaging locked, are they worth locking?
Lastly, I have VM Heap size to 32M, is this the best for my Phone?
I've searched and haven't found anything clear enough for me regarding these questions, if they are answered somewhere just give me the link to the post.
Thank you all for your help and a Huge Thanks for Team Yoshi for there excellent ROM.
Click to expand...
Click to collapse
___________________________________________________________________
IMHO, Yoshi works for me, if it is set up correctly. Other than following the instructions in the "quasi-users guide" which really do help (http://forum.xda-developers.com/showthread.php?t=938848), some of these settings have helped for me - I have both 32A and 32B but I use the MT3G 1.2 w/3.5mm jack:
(presuming you have a 4GB SDmicro card [it's good, but higher is better if phone can handle it] and you can boot to a recovery that allows you to partition your SD card - Titanium Backup works if you want to save your apps, but if you want a fresh install, well, here it is):
1. Wipe, re-wipe and if you still are unsure... rewipe some more. Did I mention to wipe EVERYTHING (including battery stats, dalvik-cache, sd-ext... sorry for over-emphasizing this). Then use Ohsaka-Superwipe_v2 and reboot to recovery.
2. Partition SD card. I have a 4GB, so for me 512 MB a2sd space and something decent for secondary space is fine (the rest of my SD is 3.19 GB, so plenty of room).
3. Flash Ginger Yoshi 1.2.zip (works for 32A & 32B... I flashed the version with the 32A radio and IMHO I didn't like it), following whatever settings you choose (installed to partition, Zeam Launcher and 60 MB swap is what I did) then flash auto-boot-2.6.35.12-farmatito -32b-and-a.zip then reboot.
Preset settings right out of boot for my device are the following (I have tried to change the settings and reboot to weird instabilities - app lag, call-to-image lag, no ringer/vibrate, fc issues, etc., but this works for me):
CPU Governor: ONDEMAND
Compcache: DISABLED
JIT: Checked
Surface Dithering: Checked
Purging of Assets: Checked
Lock home/messaging: Unchecked
VM Heap: 48M
On average, I have 33 MB free out of 199 MB and usually the JuiceDefender stuff works to give me a boost most of the time. The phone works pretty zippy for me and reduced the call-to-image lag some folks get when receiving/making a call. Of course results may vary for you, but again, IMHO, it works for me.
Apologies if I am talking to u like if u r a noob or if I am editorializing too much. Force of habit I gotta drink the hell out of. Hope all this helps and take care.

I'll try it
Just a few questions about your recommendations:
1.- I understand that I should wipe
2.- I have a Class 4 8GB SD Card, does the class 4 good enough or should I first get a class 6 or even a class 10?
3.- I will also try these settings
Also, don't worry about talking to me like if I'm a noob, since I am a noob regarding custom ROM, Swap, Paritioning SD, CompCache, etc, etc...

For that type of device, IMO the Class IV is fine, but the Class VI or 10 offer better r/w protections for swap and functionality than a decent Class IV. If you have heavy usage, I would suggest getting something more than Class IV.
Hope this helps and post if the settings have helped you out. Later

Where's my CompCache?
I flashed auto-boot-2.6.35.12-farmatito -32b-and-a.zip and now CompCache is not showing up when I use the "Free" command:
total used free shared buffers
Mem: 112616 107964 4652 0 1492
Swap: 0 0 0
Total: 112616 107964 4652
Before flashing it, it showed numbers in the Swap now it's all 0, I've already tried disabling and re-enabling at didn't work...
Edit: I did a restore of my nandroid backup before farmatito and here is what free shows:
total used free shared buffers
Mem: 112608 100276 12332 0 332
Swap: 29272 14044 15228
Total: 141880 114320 27560

It would appear as if you might not have set the "install 60MB swap on partition" when you did the initial install of GingerYoshi. On my device, it looks like this:
total used free shared buffers
Mem: 203944 198784 5160 0 148
Swap: 60668 37708 22960
Total: 264612 236492 28120
If that isn't the case (not installing the 60MB Swap file), it is a separate issue from the Comp Cache, I believe. Try installing GingerYoshi with the install to partition, ZEAM (or LauncherPro... whichever one you choose), and THEN say YES to the "60MB on partition". You should be fine by then, but if not, let me know.
Thanks and hope it helps.

I hevn't started from scratch yet...
I'm going to get a Class 6 first before creating ext3/4 on the SD Card... In any case I'm a little reluctant on using the 60MB swap since I read too may times that it could affect the life time of the SD Card and that it's not much of an improvement... But as soon as I get a class 6 I'll try and do a clean install with an Ext3/4 with the 60M swap and see how it works.
Right now I have it like this:
Installed with: No Ext, No Swap (because of no Ext) and Zeam Launcher
In Performance I have:
CPU = Ondemand 128-576MHz (altoght I'm using SetCPU for this)
CompCache = 26%
JIT = off (since it messes up the Screen On/Off Animations among other things)
Surface Dithering = Off (I see no reason to have it on)
Allow Purging of assets = On (I see no reason to not have this on)
Lock Home and Messaging = Off (Again No reason to have this on)
VM Heap Size = 32M (seems more stable than 48M)
Edit: In any case, why does installing farmatito make me loose the CompCahche?

ElConedeTJ said:
I'm going to get a Class 6 first before creating ext3/4 on the SD Card... In any case I'm a little reluctant on using the 60MB swap since I read too may times that it could affect the life time of the SD Card and that it's not much of an improvement... But as soon as I get a class 6 I'll try and do a clean install with an Ext3/4 with the 60M swap and see how it works.
Right now I have it like this:
Installed with: No Ext, No Swap (because of no Ext) and Zeam Launcher
In Performance I have:
CPU = Ondemand 128-576MHz (altoght I'm using SetCPU for this)
CompCache = 26%
JIT = off (since it messes up the Screen On/Off Animations among other things)
Surface Dithering = Off (I see no reason to have it on)
Allow Purging of assets = On (I see no reason to not have this on)
Lock Home and Messaging = Off (Again No reason to have this on)
VM Heap Size = 32M (seems more stable than 48M)
Edit: In any case, why does installing farmatito make me loose the CompCahche?
Click to expand...
Click to collapse
In advance, I apologize. It was my belief that I said in advance that I am basing my findings on my 32A device that I physically use.
I forgot to give you the specs that I am running on my 32B device:
SAPPHIRE PVT32B SHIP S-ON G
HBOOT-1.33.0013d (SAPP30000)
CPLD-10
RADIO-2.22.28.25
Oct 21 2009,22:33:27
(Settings below based on a 2GB SDmicro... a size I would not recommend):
EXT, 60MB SWAP and ZEAM
CPU = ONDEMAND with 245 - 528MHz
CompCache = Disabled
JIT = ON
Surface Dithering = ON
Allow Purging of assets = ON
Lock Home and Messaging = Off
VM Heap Size = 48M
I ran the "free" command and I also see the 0 swap size. Hmmmmm... very interesting. I will do some research and look at the bug tracking to see if it is a GingerYoshi thing or if it is something in the way I am installing it on my device as well. As an added piece of advice, the farmatito zip is more beneficial for 32A devices like the 1.2 3.5mm jack device, so if I said to install to your device, you can generally disregard it and see if it gets you better results on the swap.
As an FYI, in terms of screen transitioning, have you checked out the "Spare Parts" included with GingerYoshi? Some of the settings may be for aesthetics or performance in tandem with your space, but perhaps it can free up more memory for the ring-to-display lag you are having. As for apps (Angry Bords, for example), the only one that works with some acceptable lag is the RIO version... blasted ARM processors.
Sorry for the confusion on my part and hope this helps.

I would love to have voice to text anyone know how I can add this to my phone or can yoshi add this to the rom?
Thanks,
Bukethead

Where's my CompCache???
Something changed and now when I run the Free command I get the following:
total used free shared buffers
Mem: 112608 106440 6168 0 2784
-/+ buffers: 103656 8952
Swap: 0 0 0
It has a different layout than before, but mainly under Swap I didn't have only 0:
total used free shared buffers
Mem: 112608 100276 12332 0 332
Swap: 29272 14044 15228
Total: 141880 114320 27560
Can anyone point me in the direction of how to troubleshoot what happened without having to wipe and flash the ROM again?
Thanks.
Edit: I had a backup of my ROM and did have the Swap numbers, So I did a backup of everything via Titanium and restored the Nadroid backup, then I restored apps, then the app data then the system data rebooting step by step and the swap still appeared, so I still have no Idea what broke the compcache but it's back now... If anyone has any idea on what could have changed, please let me know...
total used free shared buffers
Mem: 112608 105768 6840 0 32
Swap: 38280 19288 18992
Total: 150888 125056 25832

I am impressed with this rom I've been running yoshi for a few months now and I have no complaints. good job team yoshi!

enabling swap

Just to let you know that Razr I works beautifully with ZRAM swap enabled !
Moto Razr I comes with a 1G of RAM, but sometimes that is not enough. The Linux kernel uses swap space even if there is a lot of memory to page out allocated but rarely used pages, and move instead disk cache into memory.
I enabled a 256Mb ZRAM swap, and the difference in device responsivness is impressive - I can switch between applications with no lag, I get no freezes, and I'm happy with it.
To enable this, I sent a pull request to the Gamma kernel: http://forum.xda-developers.com/showthread.php?t=2217725
You will need to flash the next kernel image after the change is merged.

swap
ddalex said:
Just to let you know that Razr I works beautifully with ZRAM swap enabled !
Moto Razr I comes with a 1G of RAM, but sometimes that is not enough. The Linux kernel uses swap space even if there is a lot of memory to page out allocated but rarely used pages, and move instead disk cache into memory.
I enabled a 256Mb ZRAM swap, and the difference in device responsivness is impressive - I can switch between applications with no lag, I get no freezes, and I'm happy with it.
To enable this, I sent a pull request to the Gamma kernel: http://forum.xda-developers.com/showthread.php?t=2217725
You will need to flash the next kernel image after the change is merged.
Click to expand...
Click to collapse
A noob question: Is this similar to the swap partition in linux?

paulle said:
A noob question: Is this similar to the swap partition in linux?
Click to expand...
Click to collapse
It's a different beast.
http://forum.xda-developers.com/showthread.php?t=1851991

Can you post a tutorial?

ddalex said:
Just to let you know that Razr I works beautifully with ZRAM swap enabled !
Moto Razr I comes with a 1G of RAM, but sometimes that is not enough. The Linux kernel uses swap space even if there is a lot of memory to page out allocated but rarely used pages, and move instead disk cache into memory.
I enabled a 256Mb ZRAM swap, and the difference in device responsivness is impressive - I can switch between applications with no lag, I get no freezes, and I'm happy with it.
To enable this, I sent a pull request to the Gamma kernel: http://forum.xda-developers.com/showthread.php?t=2217725
You will need to flash the next kernel image after the change is merged.
Click to expand...
Click to collapse
I've enabled it also, it didn't help too much. Try to switch between Chrome and Skype and Hangouts, each time each app is killed. Memory management in Android sucks.

Amazon tablet optimization. Memory load pressure cured.

Favorite rom -
Faux clock / any kernel tuner -
Enable kms - (setting recommended from Google for low memory device)
Set kms page_to_scan to 100
Set kms sleep_milleseconds to 500
Enable set io scheduler from 2048k - 4096k
Ram memory pro - (this setting help with memory swap when using kms, zram, and swap file combinations)
Enable at boot setting
Set balance tuning for apps and multitasking
Setxperia - (not available in store for tablet/must find and sideload) (setting recommended from Google for low memory device)
Enable zram with 400 MB size (zram have priority before using swap file / that where the magic at) (least used data get page out to zram and then to the page file)
Set swap file to data partition with 200 MB size
Set swappiness set to 100
Create swap. Total swap setting aside should equal to 615 MB
Use zramcc to check if zram/swap working. Swap total size should be 615MB. (reduce swap file size from 400 to 200 to minimize lag when all available swap are used up)
Link2SD - no need for explanation. I used this with a fast flash card to hold my titanium backup and app linkage. This app allow me to have all my apps that I used.
Seeder 2.0 - no need for explanation. This just classic lag free app. Check the entropy resources before and after usage before complaining how old and useless this app is.
Misc -
Unload/uninstall any memory hogged app, like Facebook Messenger (takes up almost 50MB), that like to stay in the system memory permanently. Can't even kill it with task manager. DO NOT USED ANY MEMORY CLEANER OR ADVANCE TASK KILLER. This will cause a swap overload. Let android manage the memory task. Reboot the tablet once all the settings have been applied. The tablet will behave very well and feel like a more expensive tablet.
I have the stock opengapps replace all the core stock rom app. Afterward, I removed any gapp that I do not use.
My Amazon Fire experiences:
My launcher is loaded with widgets and I can pretty much open any application that I used without any freeze or as little lag as possible. I game on this table now and no longer use my phone. Brave frontier and valkyrie crusade.
https://01.org/android-ia/user-guides/android-memory-tuning-android-5.0-and-5.1
Sent from my KFFOWI using Tapatalk

Kms or Ksm???

Update on information
Is all of this information still up to date? Any new additions/tweaks?
Also for some reason, after using zramcc I don't see 615 I only see 415 total.

svvparakala said:
Is all of this information still up to date? Any new additions/tweaks?
Also for some reason, after using zramcc I don't see 615 I only see 415 total.
Click to expand...
Click to collapse
Err...not really...although much of the guidance is reasonable albeit not optimal IMHO. Check out "L Speed" if seeking a quick tuner with a large following and solid reputation. Tweak one thing at a time and assess benefits before moving to the next item.