commit 2ad8b26d087bdd92520c2a8d9232b185889d6bd7
author Jared Duke <jdduke@google.com> Mon Nov 29 16:51:45 2021 -0800
committer Treehugger Robot <treehugger-gerrit@google.com> Wed Dec 01 22:36:52 2021 +0000
tree 3628f8b750a2ca4931b6dd03139c88ad9c2a5204
parent 4b762130d8c9d7d1697a3a71b7ba90ed311c306f

Suppress vdex madvise calls for metadata access

The vdex madvise calls were made to improve app startup. However, vdex
files can also be loaded in other scenarios, like when system_server
queries the dex optimization status for various packages during app
transitions, or during a global dumpsys. Avoid calling madvise in such
situations, as it incurs unnecessary latency/memory overhead.

A follow-up CL will consolidate the different dex and vdex madvise
paths; much of the dex madvise behavior was conditioned on 512MB
Go devices, and is no longer actively used.

Test: Verified madvise only called on app startup, and not from
    deprecated calls to DexFile opt status queries from system_server.
Bug: 195793112
Change-Id: I715af7f34b31f2e9060f3d3d57a2a3171f01187b

runtime/oat_file_manager.cc

diff --git a/runtime/oat_file_manager.cc b/runtime/oat_file_manager.cc
index dfa4518..3449919 100644
--- a/runtime/oat_file_manager.cc
+++ b/runtime/oat_file_manager.cc
@@ -344,6 +344,18 @@
       }
 
       if (oat_file != nullptr) {
+        VdexFile* vdex_file = oat_file->GetVdexFile();
+        if (vdex_file != nullptr) {
+          // Opened vdex file from an oat file, madvise it to its loaded state.
+          // TODO(b/196052575): Unify dex and vdex madvise knobs and behavior.
+          const size_t madvise_size_limit = Runtime::Current()->GetMadviseWillNeedSizeVdex();
+          Runtime::MadviseFileForRange(madvise_size_limit,
+                                       vdex_file->Size(),
+                                       vdex_file->Begin(),
+                                       vdex_file->End(),
+                                       vdex_file->GetName());
+        }
+
         VLOG(class_linker) << "Registering " << oat_file->GetLocation();
         *out_oat_file = RegisterOatFile(std::move(oat_file));
       }

runtime/vdex_file.cc

diff --git a/runtime/vdex_file.cc b/runtime/vdex_file.cc
index 58bb357..0afa131 100644
--- a/runtime/vdex_file.cc
+++ b/runtime/vdex_file.cc
@@ -151,20 +151,6 @@
     return nullptr;
   }
 
-  if (!writable) {
-    Runtime* runtime = Runtime::Current();
-    // The runtime might not be available at this point if we're running
-    // dex2oat or oatdump.
-    if (runtime != nullptr) {
-      size_t madvise_size_limit = runtime->GetMadviseWillNeedSizeVdex();
-      Runtime::MadviseFileForRange(madvise_size_limit,
-                                   vdex->Size(),
-                                   vdex->Begin(),
-                                   vdex->End(),
-                                   vdex_filename);
-    }
-  }
-
   return vdex;
 }