Don't sparse right-sized ext4 and erofs images.

When we introduced Dynamic Partitions, we stopped giving readonly
partitions fixed sizes. In addition we introduced deduplication for
ext4. These two factors greatly reduce the impact of sparse images,
since there aren't many fill blocks to optimize.

This patch disables sparsing for images that are rightsized and do not
explicitly specify extra reserved space. This makes the images a little
easier to work with from an engineering perspective. They no longer have
to be unsparsed to interact with any tooling. It also eases a potential
source of bugs, as b/184225422 is not reproducible with sparsing off.

On Pixel, the difference between the sparsed partitions and unsparsed is
12M (out of roughly 4G).

Bug: 198001223
Test: make, treehugger, make target-files-package
      dynamic partitions are no longer sparse images
Change-Id: I74459f8abe74a15a24ba5a40cf701e6af2db8179
3 files changed
tree: da5153b66e1d02371505a5d24e7e372ce952cfff
  1. common/
  2. core/
  3. packaging/
  4. target/
  5. tests/
  6. tools/
  7. .gitignore
  8. Android.bp
  9. banchanHelp.sh
  10. buildspec.mk.default
  11. Changes.md
  12. CleanSpec.mk
  13. Deprecation.md
  14. envsetup.sh
  15. help.sh
  16. METADATA
  17. navbar.md
  18. OWNERS
  19. PREUPLOAD.cfg
  20. rbesetup.sh
  21. README.md
  22. tapasHelp.sh
  23. Usage.txt
README.md

Android Make Build System

This is the Makefile-based portion of the Android Build System.

For documentation on how to run a build, see Usage.txt

For a list of behavioral changes useful for Android.mk writers see Changes.md

For an outdated reference on Android.mk files, see build-system.html. Our Android.mk files look similar, but are entirely different from the Android.mk files used by the NDK build system. When searching for documentation elsewhere, ensure that it is for the platform build system -- most are not.

This Makefile-based system is in the process of being replaced with Soong, a new build system written in Go. During the transition, all of these makefiles are read by Kati, and generate a ninja file instead of being executed directly. That's combined with a ninja file read by Soong so that the build graph of the two systems can be combined and run as one.