From d886cfe2bc932cc8bad9c08b3477bbc3ec31176a Mon Sep 17 00:00:00 2001 From: Mathieu Chartier Date: Tue, 26 Nov 2019 11:04:17 -0800 Subject: [PATCH] Use resetJitCounters for boot image profiling For boot image profiling, use resetJitCounters instead of disabling preloading. This improves startup for the configuration by up to 20%. Bug: 139883463 Bug: 142564450 Test: atest BootImageProfileTest Change-Id: I11274ae623d3f0032e68f6f205447ad4d200620b --- .../com/android/internal/os/ZygoteInit.java | 28 +++++++++++-------- 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/core/java/com/android/internal/os/ZygoteInit.java b/core/java/com/android/internal/os/ZygoteInit.java index ad4c6dd7a92b3..93e61020ff191 100644 --- a/core/java/com/android/internal/os/ZygoteInit.java +++ b/core/java/com/android/internal/os/ZygoteInit.java @@ -248,18 +248,6 @@ public class ZygoteInit { InputStream is; try { - // If we are profiling the boot image, avoid preloading classes. - // Can't use device_config since we are the zygote. - String prop = SystemProperties.get( - "persist.device_config.runtime_native_boot.profilebootclasspath", ""); - // Might be empty if the property is unset since the default is "". - if (prop.length() == 0) { - prop = SystemProperties.get("dalvik.vm.profilebootclasspath", ""); - } - if ("true".equals(prop)) { - return; - } - is = new FileInputStream(PRELOADED_CLASSES); } catch (FileNotFoundException e) { Log.e(TAG, "Couldn't find " + PRELOADED_CLASSES + "."); @@ -339,6 +327,22 @@ public class ZygoteInit { runtime.preloadDexCaches(); Trace.traceEnd(Trace.TRACE_TAG_DALVIK); + // If we are profiling the boot image, reset the Jit counters after preloading the + // classes. We want to preload for performance, and we can use method counters to + // infer what clases are used after calling resetJitCounters, for profile purposes. + // Can't use device_config since we are the zygote. + String prop = SystemProperties.get( + "persist.device_config.runtime_native_boot.profilebootclasspath", ""); + // Might be empty if the property is unset since the default is "". + if (prop.length() == 0) { + prop = SystemProperties.get("dalvik.vm.profilebootclasspath", ""); + } + if ("true".equals(prop)) { + Trace.traceBegin(Trace.TRACE_TAG_DALVIK, "ResetJitCounters"); + runtime.resetJitCounters(); + Trace.traceEnd(Trace.TRACE_TAG_DALVIK); + } + // Bring back root. We'll need it later if we're in the zygote. if (droppedPriviliges) { try {