Determine GC type based on BUILT_KERNEL_VERSION_FILE.
How it works:
1. build/make/core/Makefile generates a txt file with the kernel
version, which is taken from an explicit BOARD_KERNEL_VERSION value,
or extracted from the kernel image on the source tree, or extracted
from the kernel image extracted from the prebuilt boot.img.
The file is saved at
$ANDROID_PRODUCT_OUT/obj/PACKAGING/check_vintf_all_intermediates/kernel_version.txt.
2. If PRODUCT_ENABLE_UFFD_GC is "default", meaning the GC type needs to
be determined by the kernel version, build/make/core/Makefile copies
kernel_version.txt to
out/soong/dexpreopt/kernel_version_for_uffd_gc.txt.
3. build/soong/dexpreopt/config.go writes the the UFFD GC flag to
out/soong/dexpreopt/uffd_gc_flag.txt. The flag is determined by an
explicit PRODUCT_ENABLE_UFFD_GC value or by contruct_uffd_gc_flag.py,
which reads kernel_version_for_uffd_gc.txt and determines the flag
accordingly.
4. dex2oat takes the UFFD GC flag from uffd_gc_flag.txt.
5. post_process_props.py mangles ro.dalvik.vm.enable_uffd_gc based on
the same logic.
Bug: 321751629
Bug: 319554951
Bug: 318763448
Bug: 319648491
Test: m --no-skip-soong-tests nothing
Test: atest uffd_gc_utils_test
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=default m` for device with no
UFFD support -
1. Check the existence of `-Xgc:CMC` in
out/soong/dexpreopt_arm64/dex_bootjars/android/system/framework/arm64/boot.invocation
(dex2oat invocation for a boot image)
2. Check the existence of `-Xgc:CMC` in
out/soong/.intermediates/packages/apps/Settings/Settings/android_common/dexpreopt/Settings/oat/arm64/package.invocation
(dex2oat invocation for an app defined in .bp)
3. Check the existence of `-Xgc:CMC` in
$ANDROID_PRODUCT_OUT/obj/APPS/Dialer_intermediates/oat/arm64/package.invocation
(dex2oat invocation for an app defined in .mk)
4. Check the value of ro.dalvik.vm.enable_uffd_gc in
$ANDROID_PRODUCT_OUT/product/etc/build.prop
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=default m` for device with
UFFD support, and do the steps above.
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=true m`, and do the steps
above.
Test: Build with `OVERRIDE_ENABLE_UFFD_GC=false m`, and do the steps
above.
Change-Id: I8df6e5be1644da05d2d5c57b3520f29601dfd7a4
diff --git a/core/art_config.mk b/core/art_config.mk
index f47a8e2..54bfd6b 100644
--- a/core/art_config.mk
+++ b/core/art_config.mk
@@ -12,38 +12,15 @@
# ENABLE_UFFD_GC: Whether to use userfaultfd GC.
config_enable_uffd_gc := \
- $(firstword $(OVERRIDE_ENABLE_UFFD_GC) $(PRODUCT_ENABLE_UFFD_GC))
+ $(firstword $(OVERRIDE_ENABLE_UFFD_GC) $(PRODUCT_ENABLE_UFFD_GC) default)
-ifeq (,$(filter-out default,$(config_enable_uffd_gc)))
- ENABLE_UFFD_GC := true
-
- # Disable userfaultfd GC if the device doesn't support it (i.e., if
- # `min(ro.board.api_level ?? ro.board.first_api_level ?? MAX_VALUE,
- # ro.product.first_api_level ?? ro.build.version.sdk ?? MAX_VALUE) < 31`)
- # This logic aligns with how `ro.vendor.api_level` is calculated in
- # `system/core/init/property_service.cpp`.
- # We omit the check on `ro.build.version.sdk` here because we are on the latest build system.
- board_api_level := $(firstword $(BOARD_API_LEVEL) $(BOARD_SHIPPING_API_LEVEL))
- ifneq (,$(board_api_level))
- ifeq (true,$(call math_lt,$(board_api_level),31))
- ENABLE_UFFD_GC := false
- endif
- endif
-
- ifneq (,$(PRODUCT_SHIPPING_API_LEVEL))
- ifeq (true,$(call math_lt,$(PRODUCT_SHIPPING_API_LEVEL),31))
- ENABLE_UFFD_GC := false
- endif
- endif
-else ifeq (true,$(config_enable_uffd_gc))
- ENABLE_UFFD_GC := true
-else ifeq (false,$(config_enable_uffd_gc))
- ENABLE_UFFD_GC := false
-else
+ifeq (,$(filter default true false,$(config_enable_uffd_gc)))
$(error Unknown PRODUCT_ENABLE_UFFD_GC value: $(config_enable_uffd_gc))
endif
-ADDITIONAL_PRODUCT_PROPERTIES += ro.dalvik.vm.enable_uffd_gc=$(ENABLE_UFFD_GC)
+ENABLE_UFFD_GC := $(config_enable_uffd_gc)
+# If the value is "default", it will be mangled by post_process_props.py.
+ADDITIONAL_PRODUCT_PROPERTIES += ro.dalvik.vm.enable_uffd_gc=$(config_enable_uffd_gc)
# Create APEX_BOOT_JARS_EXCLUDED which is a list of jars to be removed from
# ApexBoorJars when built from mainline prebuilts.