Determine whether to enable userfaultfd GC at build time.
This is determined by:
- a product config flag
- the vendor API level
It is then passed to the device as a system property
"ro.dalvik.vm.enable_uffd_gc".
This change is a no-op change. It doesn't enable userfaultfd GC by
default. OVERRIDE_ENABLE_UFFD_GC=default can be passed to the build
system to enable userfaultfd GC for testing purposes.
Bug: 242553398
Test: -
1. lunch aosp_redfin-userdebug
2. OVERRIDE_ENABLE_UFFD_GC=default build/soong/soong_ui.bash --dumpvars-mode --vars=ENABLE_UFFD_GC
3. See "false" in the output
Test: -
1. lunch aosp_oriole-userdebug
2. OVERRIDE_ENABLE_UFFD_GC=default build/soong/soong_ui.bash --dumpvars-mode --vars=ENABLE_UFFD_GC
3. See "true" in the output
Test: -
1. lunch aosp_redfin-userdebug
2. OVERRIDE_ENABLE_UFFD_GC=true build/soong/soong_ui.bash --dumpvars-mode --vars=ENABLE_UFFD_GC
3. See "true" in the output
Test: -
1. lunch aosp_oriole-userdebug
2. OVERRIDE_ENABLE_UFFD_GC=false build/soong/soong_ui.bash --dumpvars-mode --vars=ENABLE_UFFD_GC
3. See "false" in the output
Change-Id: Ifd6e6cddb502315912ff949619a5b526ae0d73ff
diff --git a/core/OWNERS b/core/OWNERS
index d48ceab..762d2a7 100644
--- a/core/OWNERS
+++ b/core/OWNERS
@@ -1,4 +1,5 @@
-per-file *dex_preopt*.* = ngeoffray@google.com,skvadrik@google.com
+per-file *dex_preopt*.* = jiakaiz@google.com,ngeoffray@google.com,skvadrik@google.com
+per-file art_*.* = jiakaiz@google.com,ngeoffray@google.com,skvadrik@google.com
per-file verify_uses_libraries.sh = ngeoffray@google.com,skvadrik@google.com
# For global Proguard rules
diff --git a/core/art_config.mk b/core/art_config.mk
new file mode 100644
index 0000000..1ea05db
--- /dev/null
+++ b/core/art_config.mk
@@ -0,0 +1,46 @@
+# ART configuration that has to be determined after product config is resolved.
+#
+# Inputs:
+# PRODUCT_ENABLE_UFFD_GC: See comments in build/make/core/product.mk.
+# OVERRIDE_ENABLE_UFFD_GC: Overrides PRODUCT_ENABLE_UFFD_GC. Can be passed from the commandline for
+# debugging purposes.
+# BOARD_API_LEVEL: See comments in build/make/core/main.mk.
+# BOARD_SHIPPING_API_LEVEL: See comments in build/make/core/main.mk.
+# PRODUCT_SHIPPING_API_LEVEL: See comments in build/make/core/product.mk.
+#
+# Outputs:
+# ENABLE_UFFD_GC: Whether to use userfaultfd GC.
+
+config_enable_uffd_gc := \
+ $(firstword $(OVERRIDE_ENABLE_UFFD_GC) $(PRODUCT_ENABLE_UFFD_GC))
+
+ifeq (,$(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
+ $(error Unknown PRODUCT_ENABLE_UFFD_GC value: $(config_enable_uffd_gc))
+endif
+
+ADDITIONAL_PRODUCT_PROPERTIES += ro.dalvik.vm.enable_uffd_gc=$(ENABLE_UFFD_GC)
diff --git a/core/dex_preopt_config.mk b/core/dex_preopt_config.mk
index c11b7f4..ea8389a 100644
--- a/core/dex_preopt_config.mk
+++ b/core/dex_preopt_config.mk
@@ -130,6 +130,7 @@
$(call add_json_str, Dex2oatXmx, $(DEX2OAT_XMX))
$(call add_json_str, Dex2oatXms, $(DEX2OAT_XMS))
$(call add_json_str, EmptyDirectory, $(OUT_DIR)/empty)
+ $(call add_json_bool, EnableUffdGc, $(ENABLE_UFFD_GC))
ifdef TARGET_ARCH
$(call add_json_map, CpuVariant)
diff --git a/core/main.mk b/core/main.mk
index 2e39601..0453cda 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -493,6 +493,8 @@
# Typical build; include any Android.mk files we can find.
#
+include $(BUILD_SYSTEM)/art_config.mk
+
# Bring in dex_preopt.mk
# This creates some modules so it needs to be included after
# should-install-to-system is defined (in order for base_rules.mk to function
diff --git a/core/product.mk b/core/product.mk
index dcfdf1f..4c642b8 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -370,6 +370,18 @@
# If true, installs a full version of com.android.virt APEX.
_product_single_value_vars += PRODUCT_AVF_ENABLED
+# Whether to use userfaultfd GC.
+# Possible values are:
+# - "default" or empty: both the build system and the runtime determine whether to use userfaultfd
+# GC based on the vendor API level
+# - "true": forces the build system to use userfaultfd GC regardless of the vendor API level; the
+# runtime determines whether to use userfaultfd GC based on the kernel support. Note that the
+# device may have to re-compile everything on the first boot if the kernel doesn't support
+# userfaultfd
+# - "false": disallows the build system and the runtime to use userfaultfd GC even if the device
+# supports it
+_product_single_value_vars += PRODUCT_ENABLE_UFFD_GC
+
.KATI_READONLY := _product_single_value_vars _product_list_vars
_product_var_list :=$= $(_product_single_value_vars) $(_product_list_vars)
diff --git a/core/soong_config.mk b/core/soong_config.mk
index b000df6..7d3ae23 100644
--- a/core/soong_config.mk
+++ b/core/soong_config.mk
@@ -9,6 +9,7 @@
endif
endif
+include $(BUILD_SYSTEM)/art_config.mk
include $(BUILD_SYSTEM)/dex_preopt_config.mk
ifeq ($(WRITE_SOONG_VARIABLES),true)