7028394: Newer AMD Processor Prefetch Defaults
Summary: This new default has shown improvement across many workloads.
Reviewed-by: kvn
Contributed-by: tom.deneau@amd.com
--- a/hotspot/src/cpu/x86/vm/vm_version_x86.cpp Fri Mar 11 22:34:57 2011 -0800
+++ b/hotspot/src/cpu/x86/vm/vm_version_x86.cpp Thu Mar 17 12:08:01 2011 -0700
@@ -436,6 +436,13 @@
UseCountLeadingZerosInstruction = true;
}
}
+
+ // On family 21 processors default is no sw prefetch
+ if ( cpu_family() == 21 ) {
+ if (FLAG_IS_DEFAULT(AllocatePrefetchStyle)) {
+ AllocatePrefetchStyle = 0;
+ }
+ }
}
if( is_intel() ) { // Intel cpus specific settings