commit eab0cdf2874a1cc32a3214cdb772ee805db49fbd
author Alan Stokes <alanstokes@google.com> Wed Mar 01 12:13:23 2023 +0000
committer Alan Stokes <alanstokes@google.com> Mon Mar 06 12:14:12 2023 +0000
tree 8ad54d0a874086360efbf305c4dd6d3f6e81678d
parent 466d7580f2461c7065f420475ef14c05fbf7417e

Reduce virtmgr threads

16 incoming threads is too many, especially since they are started
immediately. Instead reduce it to 2 - chosen slightly arbitrarily.

Remove the explicit configuration of outgoing threads/connections; the
default (10) should be fine.

See the comments on aosp/2461836.

Bug: 245727626
Test: atest MicrodroidTests
Change-Id: I7c7bef09411d649aed3b2914a88100dff22c0dbd

javalib/jni/android_system_virtualmachine_VirtualizationService.cpp

diff --git a/javalib/jni/android_system_virtualmachine_VirtualizationService.cpp b/javalib/jni/android_system_virtualmachine_VirtualizationService.cpp
index 6659a57..fbd1fd5 100644
--- a/javalib/jni/android_system_virtualmachine_VirtualizationService.cpp
+++ b/javalib/jni/android_system_virtualmachine_VirtualizationService.cpp
@@ -29,7 +29,7 @@
 using namespace android::base;
 
 static constexpr const char VIRTMGR_PATH[] = "/apex/com.android.virt/bin/virtmgr";
-static constexpr size_t VIRTMGR_THREADS = 16;
+static constexpr size_t VIRTMGR_THREADS = 2;
 
 extern "C" JNIEXPORT jint JNICALL
 Java_android_system_virtualmachine_VirtualizationService_nativeSpawn(
@@ -83,7 +83,6 @@
     ARpcSession_setFileDescriptorTransportMode(session.get(),
                                                ARpcSession_FileDescriptorTransportMode::Unix);
     ARpcSession_setMaxIncomingThreads(session.get(), VIRTMGR_THREADS);
-    ARpcSession_setMaxOutgoingConnections(session.get(), VIRTMGR_THREADS);
     // SAFETY - ARpcSession_setupUnixDomainBootstrapClient does not take ownership of clientFd.
     auto client = ARpcSession_setupUnixDomainBootstrapClient(session.get(), clientFd);
     return AIBinder_toJavaBinder(env, client);

vmclient/src/lib.rs

diff --git a/vmclient/src/lib.rs b/vmclient/src/lib.rs
index 77ddf05..d67d87e 100644
--- a/vmclient/src/lib.rs
+++ b/vmclient/src/lib.rs
@@ -57,7 +57,7 @@
     "android.system.virtualizationservice";
 
 const VIRTMGR_PATH: &str = "/apex/com.android.virt/bin/virtmgr";
-const VIRTMGR_THREADS: usize = 16;
+const VIRTMGR_THREADS: usize = 2;
 
 fn posix_pipe() -> Result<(OwnedFd, OwnedFd), io::Error> {
     use nix::fcntl::OFlag;
@@ -122,7 +122,6 @@
         let session = RpcSession::new();
         session.set_file_descriptor_transport_mode(FileDescriptorTransportMode::Unix);
         session.set_max_incoming_threads(VIRTMGR_THREADS);
-        session.set_max_outgoing_connections(VIRTMGR_THREADS);
         session
             .setup_unix_domain_bootstrap_client(self.client_fd.as_fd())
             .map_err(|_| io::Error::from(io::ErrorKind::ConnectionRefused))