Enable 16 KB page size

Android 15 (AOSP experimental) and higher have support for building Android with a 16 KB page size. This option uses additional memory but improves system performance.

16 KB pages are only supported on arm64 targets with 16 KB kernels. However, there is also an option to simulate 16 KB userspace on x86_64 for Cuttlefish.

To enable 16 KB pages, set the following build options on a device:

  • PRODUCT_NO_BIONIC_PAGE_SIZE_MACRO := true removes the PAGE_SIZE define, and it makes components determine page size at runtime.
  • PRODUCT_MAX_PAGE_SIZE_SUPPORTED := 16384 which ensures platform ELF files are built with 16 KB alignment. This larger-than-needed size is for future compatibility. With 16 KB ELF alignment, the kernel can support 4 KB/16 KB page sizes.

Verify build flags

After selecting the lunch target, verify that the build flags are set up correctly in the environment:

$ source build/envsetup.sh
$ lunch target


If the previous two commands return 16384 and true respectively, your build flags are set up correctly.

Build shared libraries with 16 KB ELF alignment

To build shared libraries that are part of the android project, you only need to set these build flags in your target:


To build shared libraries that aren't part of android project, you need to pass this linker flag:


Verify binaries and prebuilts for 16 KB ELF alignment

The best way to verify alignment and runtime behavior is to test and run on a 16 KB compiled kernel. However, in order to catch some issues earlier:

  • Starting in Android W (AOSP experimental), you can set PRODUCT_CHECK_PREBUILT_MAX_PAGE_SIZE := true at build time. Use ignore_max_page_size: true in Android.bp and LOCAL_IGNORE_MAX_PAGE_SIZE := true in Android.mk to temporarily ignore them. These settings verify all prebuilts and allow you to detect when one is updated but is not 16 KB aligned.

  • You can run atest elf_alignment_test which verifies the alignment of on-device ELF files on devices launching with Android 15 (AOSP experimental) and later.