Enable dex madvise hints for low ram devices
Enable layout based madvise hints for low ram devices.
Reduces flash reads by 40% for AUPT use cases on low ram devices.
Test: build and flash
Bug: 63178181
(cherry picked from commit 63199d75a146cbcac1cbcac944cf054524ca8848)
Change-Id: Ica0abc10b8356fbd7ab38a71df91c2da74bf505b
diff --git a/runtime/oat_file.cc b/runtime/oat_file.cc
index 2d8d6ba..d9cfa53 100644
--- a/runtime/oat_file.cc
+++ b/runtime/oat_file.cc
@@ -75,7 +75,7 @@
static constexpr bool kPrintDlOpenErrorMessage = false;
// If true, we advise the kernel about dex file mem map accesses.
-static constexpr bool kMadviseDexFileAccesses = false;
+static constexpr bool kMadviseDexFileAccesses = true;
// Note for OatFileBase and descendents:
//
@@ -1498,11 +1498,13 @@
// Madvise the dex file based on the state we are moving to.
void OatDexFile::MadviseDexFile(const DexFile& dex_file, MadviseState state) {
- if (!kMadviseDexFileAccesses) {
+ const bool low_ram = Runtime::Current()->GetHeap()->IsLowMemoryMode();
+ // TODO: Also do madvise hints for non low ram devices.
+ if (!kMadviseDexFileAccesses || !low_ram) {
return;
}
if (state == MadviseState::kMadviseStateAtLoad) {
- if (Runtime::Current()->GetHeap()->IsLowMemoryMode()) {
+ if (low_ram) {
// Default every dex file to MADV_RANDOM when its loaded by default for low ram devices.
// Other devices have enough page cache to get performance benefits from loading more pages
// into the page cache.