Merge pull request #20051 from mpirvu/tlhfix-0.47.0

(0.47.0) Disable TLH prefetching for portable AOT code
eclipse-openj9 · Aug 23, 2024 · 94a324c · 94a324c
2 parents 9bd7a57 + 6db5d74
commit 94a324c
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Showing 2 changed files with 11 additions and 5 deletions.
diff --git a/runtime/compiler/control/J9Options.cpp b/runtime/compiler/control/J9Options.cpp
@@ -2179,15 +2179,21 @@ void J9::Options::preProcessTLHPrefetch(J9JavaVM *vm)
 #elif defined(TR_HOST_ARM64)
    preferTLHPrefetch = true;
 #else // TR_HOST_X86
-   preferTLHPrefetch =
-      (TR::Compiler->target.cpu.isGenuineIntel() &&
-       TR::Compiler->target.cpu.isAtMost(OMR_PROCESSOR_X86_INTEL_BROADWELL)) ||
-      !TR::Compiler->target.cpu.isGenuineIntel();
+   preferTLHPrefetch = !TR::Compiler->target.cpu.isGenuineIntel() ||
+       TR::Compiler->target.cpu.isAtMost(OMR_PROCESSOR_X86_INTEL_BROADWELL);
 
    // Disable TM on x86 because we cannot tell whether a Haswell chip supports
    // TM or not, plus it's killing the performance on dayTrader3
    self()->setOption(TR_DisableTM);
 #endif
+   // For portable AOT code we want to disable TLH prefetch
+   if (preferTLHPrefetch &&
+       J9_ARE_ANY_BITS_SET(vm->extendedRuntimeFlags2, J9_EXTENDED_RUNTIME2_ENABLE_PORTABLE_SHARED_CACHE) &&
+       self() == TR::Options::getAOTCmdLineOptions()
+      )
+      {
+      preferTLHPrefetch = false;
+      }
 
    IDATA notlhPrefetch = FIND_ARG_IN_VMARGS(EXACT_MATCH, J9::Options::_externalOptionStrings[J9::ExternalOptions::XnotlhPrefetch], 0);
    IDATA tlhPrefetch = FIND_ARG_IN_VMARGS(EXACT_MATCH, J9::Options::_externalOptionStrings[J9::ExternalOptions::XtlhPrefetch], 0);

diff --git a/runtime/compiler/runtime/RelocationRuntime.cpp b/runtime/compiler/runtime/RelocationRuntime.cpp
@@ -938,7 +938,7 @@ TR_RelocationRuntime::generateFeatureFlags(TR_FrontEnd *fe)
    if (TR::Options::getCmdLineOptions()->getOption(TR_DisableTraps))
       featureFlags |= TR_FeatureFlag_DisableTraps;
 
-   if (TR::Options::getCmdLineOptions()->getOption(TR_TLHPrefetch))
+   if (TR::Options::getAOTCmdLineOptions()->getOption(TR_TLHPrefetch))
       featureFlags |= TR_FeatureFlag_TLHPrefetch;
 
    if (TR::CodeCacheManager::instance()->codeCacheConfig().needsMethodTrampolines())