JIT tuning; set cache size on command line

The tuning knobs for triggering trace compilation for the JIT
had not been revisited for several years.  In that time, the
working set of some applications have significantly increased,
leading to frequent cache overlows & flushes.

This CL adds the ability to set the maximum size of the JIT's
cache on the command line, and we expect to use different settings
depending on device configuration (rule of thumb: 1K for each 1M
for system RAM, with 2M limit).

Additionally, the trace compilation trigger has been tightened to
limit the compilation of cold traces.

Change-Id: Ice22c5d9d46a93e465c57dd83f50ca3912f1672e

5 files changed, 30 insertions, 4 deletions

diff --git a/vm/compiler/codegen/arm/Assemble.cpp b/vm/compiler/codegen/arm/Assemble.cpp
index 7406d3e88..ac4e64c11 100644
--- a/vm/compiler/codegen/arm/Assemble.cpp
+++ b/vm/compiler/codegen/arm/Assemble.cpp
@@ -2148,6 +2148,8 @@ void dvmCompilerSortAndPrintTraceProfiles()
     }
 
     ALOGD("JIT: Average execution count -> %d",(int)(sum / numTraces));
+    // How efficiently are we using code cache memory?  Bigger is better.
+    ALOGD("JIT: CodeCache efficiency -> %.2f",(float)sum / (float)gDvmJit.codeCacheByteUsed);
 
     /* Dump the sorted entries. The count of each trace will be reset to 0. */
     for (i=0; i < gDvmJit.jitTableSize; i++) {
diff --git a/vm/compiler/codegen/arm/armv5te-vfp/ArchVariant.cpp b/vm/compiler/codegen/arm/armv5te-vfp/ArchVariant.cpp
index 713ecfa10..6c89b11e9 100644
--- a/vm/compiler/codegen/arm/armv5te-vfp/ArchVariant.cpp
+++ b/vm/compiler/codegen/arm/armv5te-vfp/ArchVariant.cpp
@@ -55,7 +55,13 @@ bool dvmCompilerArchVariantInit(void)
     if (gDvmJit.threshold == 0) {
         gDvmJit.threshold = 200;
     }
-    gDvmJit.codeCacheSize = 512*1024;
+    if (gDvmJit.codeCacheSize == DEFAULT_CODE_CACHE_SIZE) {
+      gDvmJit.codeCacheSize = 512 * 1024;
+    } else if ((gDvmJit.codeCacheSize == 0) && (gDvm.executionMode == kExecutionModeJit)) {
+      gDvm.executionMode = kExecutionModeInterpFast;
+    }
+    /* Hard limit for Arm of 2M */
+    assert(gDvmJit.codeCacheSize <= 2 * 1024 * 1024);
 
 #if defined(WITH_SELF_VERIFICATION)
     /* Force into blocking mode */
diff --git a/vm/compiler/codegen/arm/armv5te/ArchVariant.cpp b/vm/compiler/codegen/arm/armv5te/ArchVariant.cpp
index 25d650e6d..5c7fbbe41 100644
--- a/vm/compiler/codegen/arm/armv5te/ArchVariant.cpp
+++ b/vm/compiler/codegen/arm/armv5te/ArchVariant.cpp
@@ -55,7 +55,13 @@ bool dvmCompilerArchVariantInit(void)
     if (gDvmJit.threshold == 0) {
         gDvmJit.threshold = 200;
     }
-    gDvmJit.codeCacheSize = 512*1024;
+    if (gDvmJit.codeCacheSize == DEFAULT_CODE_CACHE_SIZE) {
+      gDvmJit.codeCacheSize = 512 * 1024;
+    } else if ((gDvmJit.codeCacheSize == 0) && (gDvm.executionMode == kExecutionModeJit)) {
+      gDvm.executionMode = kExecutionModeInterpFast;
+    }
+    /* Hard limit for Arm of 2M */
+    assert(gDvmJit.codeCacheSize <= 2 * 1024 * 1024);
 
 #if defined(WITH_SELF_VERIFICATION)
     /* Force into blocking mode */
diff --git a/vm/compiler/codegen/arm/armv7-a-neon/ArchVariant.cpp b/vm/compiler/codegen/arm/armv7-a-neon/ArchVariant.cpp
index 40ee04072..324c39879 100644
--- a/vm/compiler/codegen/arm/armv7-a-neon/ArchVariant.cpp
+++ b/vm/compiler/codegen/arm/armv7-a-neon/ArchVariant.cpp
@@ -50,7 +50,13 @@ bool dvmCompilerArchVariantInit(void)
     if (gDvmJit.threshold == 0) {
         gDvmJit.threshold = 40;
     }
-    gDvmJit.codeCacheSize = 1024*1024;
+    if (gDvmJit.codeCacheSize == DEFAULT_CODE_CACHE_SIZE) {
+      gDvmJit.codeCacheSize = 1500 * 1024;
+    } else if ((gDvmJit.codeCacheSize == 0) && (gDvm.executionMode == kExecutionModeJit)) {
+      gDvm.executionMode = kExecutionModeInterpFast;
+    }
+    /* Hard limit for Arm of 2M */
+    assert(gDvmJit.codeCacheSize <= 2 * 1024 * 1024);
 
 #if defined(WITH_SELF_VERIFICATION)
     /* Force into blocking */
diff --git a/vm/compiler/codegen/arm/armv7-a/ArchVariant.cpp b/vm/compiler/codegen/arm/armv7-a/ArchVariant.cpp
index 40ee04072..324c39879 100644
--- a/vm/compiler/codegen/arm/armv7-a/ArchVariant.cpp
+++ b/vm/compiler/codegen/arm/armv7-a/ArchVariant.cpp
@@ -50,7 +50,13 @@ bool dvmCompilerArchVariantInit(void)
     if (gDvmJit.threshold == 0) {
         gDvmJit.threshold = 40;
     }
-    gDvmJit.codeCacheSize = 1024*1024;
+    if (gDvmJit.codeCacheSize == DEFAULT_CODE_CACHE_SIZE) {
+      gDvmJit.codeCacheSize = 1500 * 1024;
+    } else if ((gDvmJit.codeCacheSize == 0) && (gDvm.executionMode == kExecutionModeJit)) {
+      gDvm.executionMode = kExecutionModeInterpFast;
+    }
+    /* Hard limit for Arm of 2M */
+    assert(gDvmJit.codeCacheSize <= 2 * 1024 * 1024);
 
 #if defined(WITH_SELF_VERIFICATION)
     /* Force into blocking */