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Ok, I've seen numerous questions about the app called HTC Performance & have disassembled the executable. While my knowledge of these thing is by no means great, I have found some very interesting functions.
Maybe someone with more reverse engineering & code experience can take a look, but with IDA Pro there are some very interesting functions & strings.
Some of the calls & code are deprecated & no longer used in WM6 + but some of them are.
It is possible, especially for evB equiped roms, that this prgram acts like a server of sorts for some programs & processes. But being as it is initiated with Smartphone only functions I doubt it.
some of the more interesting functions in the HTC Performance app are:
SHInitExtraControls Which appears to be for Smartphone only
GetSystemMetrics WM6 Pro valid - Gets System Width & Heigth in pixels. Posible uses include program optimization based on the appropriate pixel returns
CreateMutexW - coredll - used to connect to core via net cf for obtaining device info- Usually eVB related apps use to call coredll info
memmove = takes more memory than memcpy but may be used to ensure unicode strings not used on odd memory addresses, this could increase speed on apps that incorrectly do this.
InterlockedCompareExchange, InterlockedDecrement, InterlockedExchange, InterlockedExchangeAdd, and InterlockedIncrement = functions provide a simple mechanism for synchronizing access to a variable that is shared by multiple threads. The threads of different processes can use this mechanism if the variable is in shared memory.
InterlockedCompareExchange = function performs an atomic comparison of the Destination value with the Comperand value. If the Destination value is equal to the Comperand value, the Exchange value is stored in the address specified by Destination. Otherwise, no operation is performed
YAXPAX = can speed up access of written C++ Code
ReleaseMutex = Mutex functions are used to release shared functions
EnumWindows = (..) to execute a task. EnumWindows (..) enumerates through all existing windows (visible or not) and provides a handle to all of the currently open top-level windows. Each time a window is located, the function calls the delegate (named IECallBack) which in turn calls the EnumWindowCallBack (..) function and passes the window handle to it. Not sure howthis is used though.
LoadAcceleratorsW = ??? Appears to be old CE function. Deprecated???
realloc = String Optimization
malloc = RAM Allocation
GetDeviceCaps = gets dev info, can be used to the optimize redraw based on device constraints already known
LocalReAlloc = This function changes the size or the attributes of a specified local memory object. The size can increase or decrease.
EnterCriticalSection = The threads of a single process can use a critical section object for mutual-exclusion synchronization. The process is responsible for allocating the memory used by a critical section object, which it can do by declaring a variable of type CRITICAL_SECTION. can grant exclusive access to memory
ReleaseDC = This function releases a device context (DC), freeing it for use by other applications. The effect of ReleaseDC depends on the type of device context.
Again, I am not a programmer, I know a few things, & am pretty competent with the lower operations of firmware, but the rest of the CE code is not my cup of tea. There are many more functions in HTC Performance. These are only a few functions found after a brief 20 minute peak.
But maybe, maybe, some of the function calls can help us to understand if this app can be moddified to properly function on the Kaiser.
It is possible that on some evB enabled apps, that maybe some of the HTC Performance app are retained & possibly function, that is pure speculation though, & again I doubt it.
Any CE code experts out there wanna take a look? I have, & based on what I've seen, I'll have to say FICTION!
Info
Hi,
Since I haven't really had time to see whats new and all I haven't the foggiest idea what HTC Performance is/what it is supposed to do.
But I can tell you that the functions you listed are not special in any way. Most of them would appear in every application that displays anything on the screen. For instance getting system metrics is required for any application displaying scroll bars, etc. All the interlocked and critical section stuff is just thread synchronization.
But that's OK, the use of windows APIs really doesn't mean much, other than the application runs on Windows...its the non-API stuff that defines an application. If the application you're looking at writes changes to registry keys, etc. you may want to look into that as those would be the lasting changes to the device.
Cheers,
Why is there concurrency related stuff in there? Surely that should all be handled by the operating system, rather than a running application? (That said, most of my concurrency knowledge is either theoretical or based at a high level, so I could be wrong here).
High Performance Cab
You can also check this thread...
http://forum.xda-developers.com/showthread.php?t=366792
Quentin- said:
Hi,
Since I haven't really had time to see whats new and all I haven't the foggiest idea what HTC Performance is/what it is supposed to do.
But I can tell you that the functions you listed are not special in any way. Most of them would appear in every application that displays anything on the screen. For instance getting system metrics is required for any application displaying scroll bars, etc. All the interlocked and critical section stuff is just thread synchronization.
But that's OK, the use of windows APIs really doesn't mean much, other than the application runs on Windows...its the non-API stuff that defines an application. If the application you're looking at writes changes to registry keys, etc. you may want to look into that as those would be the lasting changes to the device.
Cheers,
Click to expand...
Click to collapse
No, registry would not necesarily be the place to look. For this application the registry will only report whether or not the App is running or not. It is supposed to be a speed optimization application. My thought were that it could possibly be acting as a server of sorts, handling some thread optimization & resource allocation. Correct though, most of those API's are importing device info, beyond that, I am lost as to how it handles it, if it does at all. That said, there are many things that don't show up in the registry & many things can't be altered via the registry b'c they are set or handled before initialization or loading of the registry, possibly thru the OAL. Even tougher to say in a two chip device with as little known info as the msm7xxx processors. If anyone with real coding knowledge could take a look at the executable & see just what it's doing with the info, that would be great.
dperren said:
Why is there concurrency related stuff in there? Surely that should all be handled by the operating system, rather than a running application? (That said, most of my concurrency knowledge is either theoretical or based at a high level, so I could be wrong here).
Click to expand...
Click to collapse
That is indeed the center of my question & also what leads me to question how the app functions. Is it playing a role in thread priority optimization, & possibly redraw based on the polls, or is it just a partially gutted application miising a ton of registry data that never worked?
This all works on stock/nonroot phones
I got Mono running on Android.
http://www.koushikdutta.com/2008/12/mono-on-android-success-at-last.html
Started working on Java/C# interop and found out that DLR works on Mono:
http://www.koushikdutta.com/2009/01/microsoft-dlr-and-mono-bring-python-and.html
As a result, you can write applications in Python and Ruby on Android too now.
Anyhow, if anyone else is interested in working on this project with me, please let me know! I've already gotten all the relevent source hosted at Google Code: http://code.google.com/p/androidmono. Basically the next bit of work involves implemeting a Java interop using the DLR.
Nifty.
As for Dalvik & JIT, I think dexopt already replaces some heavy usage calls with inline native code. Hopefully dalvik vm will get full JIT in the future?
This makes me very happy!!!
Thank you for your work!!
jashsu said:
Nifty.
As for Dalvik & JIT, I think dexopt already replaces some heavy usage calls with inline native code. Hopefully dalvik vm will get full JIT in the future?
Click to expand...
Click to collapse
It doesn't do any inline native replacements: dexopt optimizes the dex file. Which includes inline dex byte code replacements. There is no JIT at all, but Google said it would be something definitely on the horizon. Personally I think DEX is a pretty stupid move on Google's part; they could have just gone with CIL-- and write a Java compiler for that instead. The Mono JIT compiler works on many platforms; so V1 of Android could have been running JIT compiled native code with that route... which is an order of magnitude better in performance.
I'm going to be doing some performance comparisons of Mono vs Dalvik; Mono will obviously win, but it will be interesting to see the margin. I'll also experiment with binding Mono to the Android runtime to create Android applications in C#.
Optimization
Virtual machine interpreters typically perform certain optimizations the first time a piece of code is used. Constant pool references are replaced with pointers to internal data structures, operations that always succeed or always work a certain way are replaced with simpler forms. Some of these require information only available at runtime, others can be inferred statically when certain assumptions are made.
The Dalvik optimizer does the following:
For virtual method calls, replace the method index with a vtable index.
For instance field get/put, replace the field index with a byte offset. Also, merge the boolean / byte / char / short variants into a single 32-bit form (less code in the interpreter means more room in the CPU I-cache).
Replace a handful of high-volume calls, like String.length(), with "inline" replacements. This skips the usual method call overhead, directly switching from the interpreter to a native implementation.
Prune empty methods. The simplest example is Object.<init>, which does nothing, but must be called whenever any object is allocated. The instruction is replaced with a new version that acts as a no-op unless a debugger is attached.
Append pre-computed data. For example, the VM wants to have a hash table for lookups on class name. Instead of computing this when the DEX file is loaded, we can compute it now, saving heap space and computation time in every VM where the DEX is loaded.
All of the instruction modifications involve replacing the opcode with one not defined by the Dalvik specification. This allows us to freely mix optimized and unoptimized instructions. The set of optimized instructions, and their exact representation, is tied closely to the VM version.
Most of the optimizations are obvious "wins". The use of raw indices and offsets not only allows us to execute more quickly, we can also skip the initial symbolic resolution. Pre-computation eats up disk space, and so must be done in moderation.
There are a couple of potential sources of trouble with these optimizations. First, vtable indices and byte offsets are subject to change if the VM is updated. Second, if a superclass is in a different DEX, and that other DEX is updated, we need to ensure that our optimized indices and offsets are updated as well. A similar but more subtle problem emerges when user-defined class loaders are employed: the class we actually call may not be the one we expected to call.
These problems are addressed with dependency lists and some limitations on what can be optimized.
Click to expand...
Click to collapse
Koush said:
Personally I think DEX is a pretty stupid move on Google's part; they could have just gone with CIL-- and write a Java compiler for that instead. The Mono JIT compiler works on many platforms; so V1 of Android could have been running JIT compiled native code with that route... which is an order of magnitude better in performance.
I'm going to be doing some performance comparisons of Mono vs Dalvik; Mono will obviously win, but it will be interesting to see the margin. I'll also experiment with binding Mono to the Android runtime to create Android applications in C#.
Click to expand...
Click to collapse
Google had different objectives, they didn't go after maximum performance. Remember, that handsets have different constrains than desktops and laptops. So they went after minimizing RAM usage (byte code interpreter => maximum possible sharing of read-only memory pages among processes) and battery life. Performance had to be acceptable, not priority.
You would not be able to fit everything into RAM if you used Mono and you would get the patent problems with Net/Mono/etc as a bonus.
lu_tze said:
Google had different objectives, they didn't go after maximum performance. Remember, that handsets have different constrains than desktops and laptops. So they went after minimizing RAM usage (byte code interpreter => maximum possible sharing of read-only memory pages among processes) and battery life. Performance had to be acceptable, not priority.
You would not be able to fit everything into RAM if you used Mono and you would get the patent problems with Net/Mono/etc as a bonus.
Click to expand...
Click to collapse
.NET, C#, IL, et al are all ECMA standards. Mono is LGPL/GPL. There are no patent or licensing issues with it that is unfamiliar to the OHA. They reuse plenty of open source projects.
An interpreter is not power efficient OR performant, simply due to the fact is it doing the 10 times as much work to do the same thing as native code. In addition, Mono features an Ahead Of Time compiler (AOT) that would let you compile everything to native code before it even hits the phone (or just once, and cache it). Most of Android's power and memory optimizations currently comes from Google's application life cycle (activities can be killed and resumed at the system's whim) -- that has nothing to do with Dalvik. I'm not criticizing the API or the implementation, just the runtime.
They could have spent their time making the Mono runtime play nicely with the shared memory subsystem.
I'm rebuilding mono with a minimal configuration to check out the disk and memory footprint.
Koush said:
Not that most of you will care, but I got Mono running on Android.
Click to expand...
Click to collapse
I'm a noob.... how can I install this? Very good Job Kush!
pic.micro23 said:
I'm a noob.... how can I install this? Very good Job Kush!
Click to expand...
Click to collapse
I haven't released anything yet. I'm trying to figure out how to statically link all it's dependencies, minimize the size, bind to the Android runtime, convert DEX to CIL and then CIL to ARM, and all sorts of other goodness. Basically a lot of experimenting to do before anything is "released". It's just in proof of concept phase right now.
Dalvik sucks
http://www.koushikdutta.com/2009/01/dalvik-vs-mono.html
Koush said:
Dalvik sucks
http://www.koushikdutta.com/2009/01/dalvik-vs-mono.html
Click to expand...
Click to collapse
Lol. nice article Koush. It's surprising mono is that much faster
Koush said:
I haven't released anything yet. I'm trying to figure out how to statically link all it's dependencies, minimize the size, bind to the Android runtime, convert DEX to CIL and then CIL to ARM, and all sorts of other goodness. Basically a lot of experimenting to do before anything is "released". It's just in proof of concept phase right now.
Click to expand...
Click to collapse
Just read the dalvik vs mono article. It's certainly interesting work. I agree that by ignoring JIT they're certainly not going after the most beneficial optimizations. That said, I don't think it's something they've completely excluded from future implementation.
I think you should consider trying to get Mono added as an external project. If nothing, having unofficial support for a vm which supports C#/CIL could bring in a significant amount of developer interest from the WinMo dev community. The coretech team would be the folks to set up a new project.
I've now gotten mono working on all G1s. You don't need Debian OR root. Still a couple kinks to work out, but I have it on the market for anyone interested in playing with it. More information at the link below.
http://www.koushikdutta.com/2009/01/mono-for-android-now-available-on.html
I thought this was only a platform for development but its made my g1 much faster and reduced memory from steel and stock browsers as well. My market is still 12 mb and mono is about 11 mb. Is this normal?
Also everytime, I run mono, does it do the same thing it does the first time it was installed and opened?
Sorry, i know nothing about mono but i can tell its definitely optimizing the performance on the g1 though.
great work koushe,
hbguy
This awesome, I have been waiting to see how this all turned out after reading your first post about it a few days ago.
hbguy said:
I thought this was only a platform for development but its made my g1 much faster and reduced memory from steel and stock browsers as well. My market is still 12 mb and mono is about 11 mb. Is this normal?
Also everytime, I run mono, does it do the same thing it does the first time it was installed and opened?
Sorry, i know nothing about mono but i can tell its definitely optimizing the performance on the g1 though.
great work koushe,
hbguy
Click to expand...
Click to collapse
Koush would know more than I would, but installing mono shouldn't affect everything else on Android. It's not like everything is suddenly using mono instead of dalvik. I suspect you have a strong case of the placebo effect
hbguy said:
I thought this was only a platform for development but its made my g1 much faster and reduced memory from steel and stock browsers as well. My market is still 12 mb and mono is about 11 mb. Is this normal?
Also everytime, I run mono, does it do the same thing it does the first time it was installed and opened?
Sorry, i know nothing about mono but i can tell its definitely optimizing the performance on the g1 though.
great work koushe,
hbguy
Click to expand...
Click to collapse
Yeah, you're just imagining things I haven't even attempted like DEX->CIL yet.
The first APK of Mono is quite large though. I've updated it with a number of bug fixes and also am making it use eglib now. This trimmed the size by a few MB. Getting Mono to work with Bionic might not be possible... (that would trim off another 2MB).
Once again, the APK is just a developers release... something to play with and test.
I have been messing with mono on my G1.
Is it safe to say it will only work with command line apps?
I got my own hello world and a few other things running, but if I try and run any sort of gui I get errors.
Yes, only command line stuff will work. WinForms will not work on Android.
However, you should be able to get OpenGL ES working via PInvoke. I haven't tried it, but it should work just fine.
Koush said:
Yes, only command line stuff will work. WinForms will not work on Android.
Click to expand...
Click to collapse
That is what I thought, I think PInvoke is just a bit out of my skill set.
Thanks for the work none the less.
I got mono building in the Android build environment, and the Mono team accepted a patch to make it work on Android. There's also some changes external to Mono which can be found at the androidmono google code repository:
http://code.google.com/p/androidmono/
Did a light weight search here I don't see anything applicable.
Realizing the Linux\Android kernel is very memory friendly.
I had 1 or 2 questions.
What type of apps will put the most drag on processing as far as tasking on the Infinity?
Gaming for sure maybe.
Haven't gamed much lately so perhaps not an issue for me.
My uses are browsing like most.
Reading technical PDFs with diagrams and charts.
Letter writing.
Editing photos.
Electronic mail.
(I'll say I don't have much slowness with the above)
How are applications designed for speed?
Which type of apps present a light load on the system?
Do faster applications crash more? (with the Infinity specifically)
What are the major differences between Linux and Android?
I know a googsearch could yield info.
I just thought I could call on you guyz\galz for a spirited discussion.
all
Flames
Replies
Links
Jokes
Advice
Screenshots
accepted!
TIA
Thats OK said:
How are applications designed for speed?
Click to expand...
Click to collapse
By using fast algorithms and fast programming languages, and avoiding stupid things. Since the CPU has a fixed maximum speed, the only way to make an app faster is to execute fewer instructions to achieve the desired effect.
Thats OK said:
Which type of apps present a light load on the system?
Click to expand...
Click to collapse
Correctly programmed apps will only load the system if they have a reason (meaning, they do some work for you). Depending on what the app is supposed to do, this can be a light or a heavy load.
Reading technical PDFs with diagrams and charts -> will be a heavy load while rendering a page, and should produce virtually no load while you are reading.
Letter writing. -> should be a light load, since it will wait for your keypresses most of the time.
Editing photos. -> photo manipulation can be a heavy load, since calculations have to be applied to millions of pixels.
Electronic mail. -> see letter writing. Except if you send big attachments, then this will be a heavy load for the storage subsystem, but a light one on for the CPU.
Thats OK said:
Do faster applications crash more? (with the Infinity specifically)
Click to expand...
Click to collapse
No. Buggy apps crash more. If code is correct, it does not crash. As written above, slow applications do not really run slower or safer, they just waste more time.
Thats OK said:
What are the major differences between Linux and Android?
Click to expand...
Click to collapse
The Android kernel is a derivate of Linux that has some additional features for memory management, interprocess communication and power management.
The userspace part (everything running on top of the kernel - system libraries and applications) is very different.
Thanx!
Good information for me.
Hi
Before I mean that applications and tweaks that will give them are the ones I've used, tested and have worked for me, so if you have that you know could be so kind as to comment as you lack have managed to control the use of RAM.
I also want to say sorry if my English is bad, I had to use the Google translator on the one hand and on the other my little knowledge in English, I'm sorry.
Not if you have noticed but in the Custom Roms of our device we overuse of RAM, this becomes more noticeable even Roms based on Lollipop, as can be CyanogenMod 12 where we can see that sometimes bubbles Messenger chat can be closed or the music is turned off, so I write this guide to explain how to control this use with some applications that truth to me I have worked.
-Apps:
The truth use applications to control the use of RAM is very embarrassing, since we are no longer in a device with 180MB of RAM, and have to use Tweaks or applications that optimize this, for some use some Tweak or application on this device is something good to optimize it a bit more, but we think 1GB of RAM and a 1.2 Ghz processor with 4 core.
To control the use of RAM I recommend...
Root Booster(FULL VERSION):
https://play.google.com/store/apps/details?id=com.ram.memory.booster.cpu.saver
The truth is that this application achieving control the use of RAM on my device, but I had to buy the full version, you can use the mode solves this problem, in short, once you buy the application must be enabled mode more stability and activate (Required root to use this application, it is a bit obvious that the application is called root Booster).
AutoKiller:
Before knowing Root Booster using this application but really saw that I closed many processes necessary but the truth if I won a big improvement in the management of RAM, the truth if you run install I recommend you select the Ultimate mode.
-Tweaks:
Truth does not recommend it Tweaks init.d but the truth if they help as much as elsewhere in scrolling speed or other you run.
L-Speed:
http://forum.xda-developers.com/android/software-hacking/tweak-l-speed-v1-0-02-02-2015-t3020138
This Tweak me if I worked well to improve the speed of scrolling and a little more open applications, RAM usage but saw no improvement truth in one or another section if that worked.
Now, this is the only tweak I can recommend for this device.
-Things not recommend:
Do not mix Tweaks:
Many would say that mixing Tweaks will gain greater speed, but not really. In some cases this may cause system instability, causing not work normally, can cause terrible lags or even a brick, do not think for mixing Tweaks will gain greater speed, if your system already works well with you Tweak to mix with more.
Do not mix apps:
I say almost the same as in the previous tip, if your device and works well with an application to modify that, the truth if mixed apps can cause applications to close or in some cases are playing something and that game middle parting closure.
Well, that's all I can tell you, as I said at the beginning of the post if you have any Tweak or application that worked them to control this might share? would help users much more control this big problem, I hope you enjoyed this post and wish them well controlling this great use of RAM in their devices,
Greetings.
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Wandering through the forums and various websites dedicated to Android, we are constantly confronted with tips on how to increase the performance of the smartphone. Some recommend to include swap, others - add special value to build.prop, and others - to change variables of the Linux kernel. Such recipes in different ways you can find a huge amount of that on the XDA and 4PDA. But do they actually work
Tenacity with which some seemingly competent smartphone users are trying to push their ideas public optimum adjustment Android and the underlying Linux kernel. And the right to it was limited to a slight tuning virtual memory management subsystem, or the inclusion of experimental options. No, we usually offer a very long use scripts that change literally every variable core, remount filesystems with different odd options, including the swap, activate various system daemons and perform billions of different operations.
No, well, you can, of course, assume that the Linux kernel, Android and proprietary firmware for smartphones develop illiterate idiots, whose work must be radically alter, but in practice some reason it turns out that the most famous tuning tools, published on XDA, - it nothing but a hodgepodge of disparate huge number of recommendations, it is not clear who invented and no one knows why. The absurdity of the situation reaches that these instruments can be found rows copied unchanged from the scripts to increase Linux-server performance under heavy loads (I'm not kidding, look at the contents of the famous script ThunderBolt!).
In general, the situation is more complicated than. All advise all, no one suggests anything, and those who understand something, sitting and drinking tea and laughing over what's happening.
Swap
Let's start with the swap - the most absurd ideas of all that you can think of for use in smartphones. Its purpose is to create and connect the paging file, thereby manage to free storage space in memory. The idea itself is certainly sensible, but only if it is a server, which rests on the interactivity of nowhere. Using your phone regularly used pagefile will lead to lags arising from slips past the cache - just imagine what will happen if an application tries to display one of their icons, and it will be in the swap, which will have to re-load the disc, after freeing up space by placing data swap another application. Horror.
Some users can be argued that in fact after the swap no problems, but for this we must thank the mechanism lowmemorykiller, which regularly kills very swollen and have not used the application. Thanks to him, the device with 1GB of memory can never reach the necessary performance data in a swap. He is the reason why, in contrast to the Linux-desktop on the Android swap is not needed.
Verdict: A very stupid idea, the implementation of which is fraught with serious lags.
zRAM
The idea is so right that even Google recommends zRAM for KitKat-based devices in the event that the amount of RAM is less than 512 MB. Only snag is that the method only works for modern cost devices based on multi-core processors from the budget any MTK and 512 MB of RAM. In this case, the encryption stream can be taken to separate the kernel and do not care about performance.
On older devices with a single core, and which recommend the use of this technology, we again get the lags, and in fairly large quantities. The same, incidentally, applies to technology KSM (Kernel Same Page Merging), which allows you to combine identical memory pages, thus freeing space. It also recommended that Google, but on older devaysakh leads to an even greater lags, which makes sense, given the constantly active core thread that runs continuously from memory in search of duplicate pages.
Verdict: it depends on the device, in most cases, the system slows down.
Seeder
At the time this application has done a lot of noise and gave rise to many analogues. The network has a huge number of reports of alleged phenomenal growth performance of the smartphone after installation. Homegrown custom firmware collectors have begun to include him in their assembly, and the author was declared a savior. And all this despite the fact that Seeder not doing anything dirty hacks, but just corrected a stupid bug Android.
The bug consisted in the fact that some high-level components of the Android runtime actively used the file /dev/random to get entropy. In some moments buffer /dev/random devastated, and the system is blocked until it is filling the required amount of data. And as he filled that have been reported from various sensors, buttons and sensors of the smartphone, the time for this procedure took so much time to notice that lag.
To solve this problem the author Seeder took Linux-demon rngd, compiled it for Android inastroil so that he took random data from a much faster (but also much more predictable) /dev/urandom, and every second merges them into /dev/random, without allowing the latter exhausted. As a result - the system never experienced a lack of entropy and work quietly.
This bug was closed back in Google Android 3.0, and it would seem, we do not need to think about Seeder. But the fact that the application has since actively developed and even today, is recommended by many "experts" for the application. Moreover, the application has several analogues (eg, sEFix), and many of the creators of the scripts/tools to accelerate still include this functionality in their creations. Sometimes it is the same rngd, sometimes - the demon haveged, sometimes just symlink /dev/urandom on /dev/random.
Everyone who tried it, excitedly shouting about the effectiveness of the solution, however, according to Ricardo Cerqueira from the company Cyanogen, in newer versions of Android /dev/random is used in all three components: libcrypto (encryption SSL-connections, generating SSH keys and etc.), wpa_supplicant/hostapd (to generate the WEP/WPA-keys) and several libraries for generating random ID to create ext2/3/4 filesystems.
Application Efficiency in today's Android, in his opinion, is not connected with the completion of the pool /dev/random, and that rngd constantly awakens the device and causes it to increase the frequency of the processor, which has a positive effect on performance and negative on the battery.
Verdict: The placebo effect.
Odex
Stock firmware smartphones always odex. This means that along with the standard package for Android apps in APK format directory /system/app/ and /system/priv-app/ (since KitKat) are also of the same name files with the extension odex. They contain so-called optimized bytecode applications already passed through the validator and optimizer virtual machine and recorded in a separate file (this is done using dexopt utility).
Meaning odex files to offload virtual machine and thus speed up the launch of the application (runoff). On the other hand, ODEX files to prevent modifications to make to the firmware, create problems with the update, and for this reason many custom ROMs (including CyanogenMod) distributed without them. Return (or rather, generate) files odex a variety of ways, including using simple tools/scripts like Odexer Tool. Using them is easy, and many of the "experts" are advised to do so.
The only problem is that this is purely a placebo. Not finding odex-files in the directory/system, the system itself will create them the next loaded and placed in the directory /system/dalvik-cache/. This is what she does when loading a new firmware on the screen the message "Busy ... Optimizing Applications." In relation to applications from the convenience store is also, incidentally, works. But at the stage of installation of the software.
Verdict: The placebo effect.
Lowmemorykiller tweaks
The implementation of multitasking in Android is very different from other mobile operating systems and is based on the classical model. Applications can work quietly in the background, in the system there are no restrictions on the number, the functionality of the transition to a background execution is not curtailed. All as on the desktop, except for one detail: the system has every right to kill any background application in the case of lack of memory, or (since KitKat) excessive greed application resources.
This mechanism, called lowmemorykiller, was coined to, retaining features of a full-fledged multi-tasking OS, Android could live normally in a limited amount of memory and lack of swap-partition. The user can easily launch any application and quickly switch between them, and the system will take care of the long-unused application completion and to always remain free memory in the device.
In the early days of Android purpose of this mechanism for many users it was unclear why have become popular so-called task-killer - apps that from time to time to wake up and have completed all background applications. Profits in this case, it was considered a large amount of free RAM, which was perceived as a plus, though no advantages in this, of course, was not. But there were many disadvantages in the form of a longer switch between applications, increased battery consumption and problems c awakening in the morning the owner (Service also kills).
Over time, multitasking principles of understanding has come, and from task-killers gradually abandoned. However, they were quickly replaced by another trend - tuning of lowmemorykiller mechanism (for example, by MinFreeManager applications). The main idea of the method is to lift the boundaries of filling the RAM at which the system will start to kill background apps. A sort of the way ", and us and you", which allows you to free up some memory by regular means, without disturbing ideas Android multitasking.
But what it ultimately leads? For example, the standard value memory is full of borders - a 4, 8, 12, 24, 32 and 40 Mb, that is when the free storage space of 40 MB will be killed by one of the cached applications (loaded in memory, but is not running, is this optimization Android ), with 32 - Content Provider, has no customers, 24 - one of the seldom-used back-end application, then go to the expense of service processes application (for example, the music player service), visible on the app screen and the current running application. The difference between the last two is that the "current" - this application, which is currently dealing the user, and the "visible" - is that, for example, has a notification in the status bar or display on top of the screen any information.
In general, all this means that the smartphone will always be available 40 MB of memory, which is enough to accommodate another application, and then start LKM flow and begin cleanup. All OK, everyone is happy. The system uses the maximum memory. Now imagine what would happen if the user take advantage of advice homebrew "expert", and raise these values so that the latter would be, well, let's say, 100 MB (usually raised only the last three values). In this case, it happens one simple thing: the user will lose 100 - 40 = 60 MB of memory. Instead of using this space to store back-end applications, it is useful, as it reduces the time to switch to them, and the charge of the battery, the system will keep it free is not clear why.
It is fair to say that the LKM tuning can be useful for devices with very very little memory (less than 512) and Android 4.X on board, or to temporarily increase thresholds. Some developers tweaks directly recommend the use of "aggressive" setting only if you run heavy software like hi-end games, and all the rest of the time to stay on the standard. This really makes sense.
Verdict: better not to touch.
I/O tweaks
The scripts that are published on the forums, you can often find tweaks I/O subsystem. For example, in the same script ThunderBolt! has the following lines:
Code:
echo 0 > $i/queue/rotational;
echo 1024 > $i/queue/nr_requests;
The first gives the I/O scheduler to understand that he is dealing with a solid state drive, the second increases the maximum size of the queue IO 128 to 1024 ($i variable in commands contains a path to the tree of block device in /sys, eg /sys/block/mmcblk0/, the script runs on them in the loop). Hereinafter you can find the following line relating to the CFQ scheduler:
Code:
echo 1 > $i/queue/iosched/back_seek_penalty;
echo 1 > $i/queue/iosched/low_latency;
echo 1 > $i/queue/iosched/slice_idle;
This is followed by a few more lines belonging to other planners (by the way, pay attention to a whole extra semicolon at the end of instruction). What all of these lines is not so? The first two commands are pointless for two reasons:
1. Schedulers I / O in a modern Linux kernel itself able to understand what type of storage medium they deal.
2. Such a long input-output queue (1024) completely useless on a smartphone. Moreover, it is meaningless, even on the desktop and is used on heavy duty servers (of tuning recommendations which it, apparently, and got into the script).
The last three are meaningless for the simple reason that for a smartphone, where there is virtually no separation applications prioritized in the input-output and there is no mechanical drive, the best planner - is the noop, that is simple the FIFO-queue - who first turned to memory, he also got access. And this scheduler is not any special settings. Therefore, all these multi-screen lists commands better replaced by a simple cycle:
Code:
for i in /sys/block/mmc*; do
echo noop > $i/queue/scheduler
echo 0 > $i/queue/iostats
done
In addition to enabling noop scheduler for all drives it off the accumulation of statistics I/O, which should also have a positive impact on the performance (although this is only a drop in the sea, which will be completely invisible).
Another tweak that can often be found in the scripts tuning performance - this increase readahead values for memory cards up to 2 MB. readahead mechanism for early reading data from the media even before the application requests access to these data. If the kernel sees that someone long enough to read the data from the media, it is trying to figure out what data will be needed in the future application and pre-loads them into RAM, thereby enabling to reduce the time of their return.
It sounds cool, but, as practice shows, readahead algorithm is very often wrong, which leads to unnecessary operations of input-output and consumption of RAM. High values readahead (1-8 MB) are recommended for use in RAID-arrays, whereas on the desktop or smartphone is better to leave everything as is, that is 128 KB.
Verdict: in addition to noop, do not need anything.
Tweaks virtual memory management system
In addition to the subsystem I/O, it is also common to do tuning virtual memory management subsystem. Often, change affects only two kernel variables: vm.dirty_background_ratio and vm.dirty_ratio, which allow you to adjust the size of the buffer for storing the so-called dirty data, ie the data that has been written to disk application, but more are still in memory and waiting until they are written to disk.
Typical values of these variables in the desktop Linux-distributions and Android are as follows:
Code:
* vm.dirty_background_ratio = 10
* vm.dirty_ratio = 20
This means that when the "dirty" data buffer size in 10% of the total amount of RAM wake pdflush nuclear flow and starts to write data to disk. If the operation of recording data on the disk will be too intense and even though the job pdflush, the buffer will continue to grow, then when it reaches 20% of the amount of RAM the system switches all the subsequent write operation in synchronous mode (without pre-buffer) and the work of writing to disk application will be blocked until such time as the data is written to disk (in the terminology of Android is called a lag).
It is important to understand that even if the buffer size is not reached 10%, the system anyway pdflush starts the flow after 30 seconds. What we are given this knowledge? In fact, anything that we could use for their own purposes. The combination of 10/20% is quite reasonable, for example, on your smartphone with 1 GB of RAM is about 100/200 MB of memory, which is more than enough in terms of rare bursts records that speed is often below the speed record in system NAND-memory, or SD-card (when installing software or copying files from a computer). But the creators of scripts optimization with this, of course, disagree.
For example, in Xplix script can find something like this (in the original, they are much longer because of the checks on the amount of RAM and use BusyBox):
Code:
sysctl -w vm.dirty_background_ratio=50
sysctl -w vm.dirty_ratio=90
These commands apply to devices with 1 GB of memory, that is, set limits on "dirty" buffer equal to (approximately) 500/900 MB. These high values are absolutely meaningless for the smartphone, as only work under constant intense recording on the disc, that is, besides for heavy server. In a situation with a smartphone they are no better than the standard. By the way, in the script ThunderBolt! used much more reasonable (and close to the standard) values, but I doubt that by their application the user will notice at least some difference:
Code:
if [ "$mem" -lt 524288 ];then
sysctl -w vm.dirty_background_ratio=15;
sysctl -w vm.dirty_ratio=30;
elif [ "$mem" -lt 1049776 ];then
sysctl -w vm.dirty_background_ratio=10;
sysctl -w vm.dirty_ratio=20;
else
sysctl -w vm.dirty_background_ratio=5;
sysctl -w vm.dirty_ratio=10;
fi;
The first two commands are run on smartphones with 512 MB of RAM, the second - with 1 GB, and others - with more than 1 GB. But in fact there is only one reason to change the default settings - a device with a very slow internal memory or memory card. In this case it is reasonable to spread the values of the variables, that is, to make something like this:
Code:
sysctl -w vm.dirty_background_ratio=10
sysctl -w vm.dirty_ratio=60
Then, when a surge system write operations, without having to record data on the disc, up to the last will not switch to synchronous mode, which will allow applications to reduce lag when recording.
Verdict: better not to touch.
P.S.
There are numerous and smaller optimizations, including the "tuning" of the network stack, changing the variables of the Linux kernel and Android (build.prop), but 90% of them have no effect on the real performance of the device, while the remaining 10% or improve some aspects of behavior devices at the expense of others, or so insignificant increase productivity, you do not even notice it. From what really works, we can note the following:
****Acceleration. The small acceleration to improve performance and andervolting - save a little battery.
****Database Optimization. I seriously doubt that this will give a noticeable increase in speed, but the theory tells us that the work should be.
****Zipalign. Ironically, despite the built-in Android SDK feature content alignment within the APK-file in the store you can find a lot of software is not transmitted through zipalign.
****Disable unnecessary system services, removing unused system and seldom-used third-party applications.
****Custom kernel with optimizations for a specific device (again, not all nuclei are equally good).
****Already described I/O scheduler noop.
****Saturation algorithm TCP westwood +. There is evidence that he is in wireless networks more efficiently used in the default Android Cubic. Available in custom kernels.
Useless settings build.prop
LaraCraft304 from XDA Developers forum has conducted a study and found that an impressive number of /system/build.prop settings that are recommended for use "experts" do not exist in the source AOSP and CyanogenMod. Here's the list:
ro.ril.disable.power.collapse
ro.mot.eri.losalert.delay
ro.config.hw_fast_dormancy
ro.config.hw_power_saving
windowsmgr.max_events_per_sec
persist.cust.tel.eons
ro.max.fling_velocity
ro.min.fling_velocity
ro.kernel.checkjni
dalvik.vm.verify-bytecode
debug.performance.tuning
video.accelerate.hw
ro.media.dec.jpeg.memcap
ro.config.nocheckin
profiler.force_disable_ulog
profiler.force_disable_err_rpt
ersist.sys.shutdown.mode
ro.HOME_APP_ADJ
To be continued...
thanks man!
this helped me understand some things
"No, well, you can, of course, assume that the Linux kernel, Android and proprietary firmware for smartphones develop illiterate idiots, whose work must be radically alter"
this made me lol
This...
Was...
AWESOME!
Pure information furthermore useful bits and pieces. Sorry for the necro but I just felt plain wrong to tap a button to say thanks. I really felt like I'd be the minimum to write thanks personally. Thank you very much for this post.
I swear to you windowsmgr.max_events_per_sec works flawlessly, the higher number, the more content will be able to load on launcher without lag. I used to test it on my J7 pro android 8.0
I subscribe the OP's statements that we are constantly are searching for optimization(s) of our Android device. I used all kind of Android devices, like Sony, Oppo, etc for many years with varying satisfaction, also regarding Android updates. I know that what I'm going to say now, is very sensitive in the Android community, but nevertheless I will post it. After having used Fitbit as my fitness trackers/smartwatches, I noticed the release of the Apple iWatch 6 and I was stunned about the capabilities of this watch versus all other smarwatches. Alas I needed also an iPhone to get it up and running. Let me be clear, I never was an Apple fan due to it's too strict policy and the fact that you were not able to make your own homescreen. But, since the release of iOS 14 this all changed, so I decided to get over my Apple resistance and bought the Apple 12 Pro Max. Using this now for a few months, this is the best upgrade I ever made. Everything runs smooth, fast, lot's of space, smooth connection with the iWatch, etc etc. I designed my own home display even on an Apple device (see attachment). Looks exactly the same as the home display I had on all of my former Android devices. Hope this information is in some way helpfull for you all. Kindest regards kuzibri
P.S. If you've got interested in more information about the Apple 12, see my threads in the Apple fora of XDA:
1. https://forum.xda-developers.com/t/q-a-template-for-the-apple-iphone-12-pro-max.4322579/
2. https://forum.xda-developers.com/t/ask-away-thread-for-all-apple-iphones.4323471/