Because of developments in reminiscence administration and efficiency optimization, Android is transitioning its kernel web page measurement from 4 KB to 16 KB. This transformation impacts how functions handle reminiscence and requires builders to make sure compatibility, and was addressed in Including 16 KB web page measurement to Android and Assist 16 KB web page sizes.
Google Play has additionally printed a weblog put up (Put together your apps for Google Play’s 16 KB web page measurement compatibility requirement) asking builders to help 16 KB web page sizes of their functions.
Beginning November 1st, 2025, all new apps and updates to present apps submitted to Google Play and focusing on Android 15+ units should help 16 KB web page sizes.
Native Code
Functions containing native code have to be constructed to help 16 KB web page sizes. Confer with the official Google doc for detailed directions.
Testing Setting
Google Android Emulator supplies a testing setting for 16 KB pages.
For real-world testing, Samsung’s Distant Check Lab provides an identical setting on precise Samsung units. See Get Began with Distant Check Lab for Cell App Testing, a earlier Distant Check Lab weblog, to verify in case your software works in a 16 KB web page setting. We suggest that you simply search utilizing the key phrase “distant take a look at lab” within the Weblog checklist and look by way of different posts associated to the Distant Check Lab as nicely.
Understanding 16 KB Web page Dimension
For a common understanding of what a web page refers to within the context of an working system (OS), see Web page (Pc reminiscence).
You may consider it as a manner of managing DRAM reminiscence in models known as pages. For instance, for those who divide a bodily DRAM reminiscence of 32 KB into 4 KB pages, you get 8 pages. For those who divide it into 16 KB pages, you get 2 pages. This bodily reminiscence is mapped into the digital handle house of every course of, and the unit of this mapping is a web page. When a course of accesses a particular handle, it goes by way of a web page desk to entry the web page of the bodily reminiscence akin to the handle. If the web page measurement is elevated from 4 KB to 16 KB, allocating and mapping a reminiscence of 16 KB that might have used 4 operations can now be executed in only one. This impacts not solely in-kernel reminiscence administration, but in addition the file system and block layer, finally resulting in an enchancment in efficiency.
Kernel mmap & Software Change
Understanding the mmap API
In a Linux kernel, consumer house processes use the mmap API to map information or units into their digital handle house. One of many arguments in mmap is the offset, which is required to be a a number of of the web page measurement, as proven beneath.
Failing to stick to the requirement will fail the mmap operation. If the applying logic assumes that mmap will succeed, this may occasionally trigger the applying to crash.
The offset have to be a a number of of the web page measurement as returned by sysconf(_SC_PAGE_SIZE)
Influence of the Web page Dimension Change
When the kernel web page measurement modifications from 4 KB to 16 KB, the mmap’s offset worth should now be a a number of of 16 KB, not 4 KB. In different phrases, on a 4 KB web page kernel, offsets of 0, 4, 8, and 12 KB work accurately, however on a 16 KB web page kernel, offsets of 4, 8, and 12 KB don’t.
You may configure these mmap operations whereas constructing an software, however additionally it is doable the developer didn’t use the mmap themselves, as a result of in lots of circumstances the inner linker performs the mmap mechanically. A linker refers back to the software’s Executable and Linkable Format (ELF) to carry out the mmap. It is vital to construct the applying with 16 KB pages to ensure the linker performs the mmap to the right areas for the 16 KB web page kernel.
To reiterate, in case your software consists of native code (not simply Java), guarantee that you’ve got constructed it to help 16 KB web page sizes. For steerage, confer with this Google Doc. We now have additionally offered a shell script that you should use to confirm that your software helps the 16 KB web page measurement.
