8262326: MaxMetaspaceSize does not have to be aligned to metaspace commit alignment

Reviewed-by: coleenp, iklam

Author: tstuefe

src/hotspot/share/memory/metaspace.cpp

@@ -607,9 +607,8 @@ void Metaspace::ergo_initialize() {
   //  to commit for the Metaspace.
   //  It is just a number; a limit we compare against before committing. It
   //  does not have to be aligned to anything.
-  //  It gets used as compare value in class CommitLimiter.
-  //  It is set to max_uintx in globals.hpp by default, so by default it does
-  //  not limit anything.
+  //  It gets used as compare value before attempting to increase the metaspace
+  //  commit charge. It defaults to max_uintx (unlimited).
   //
   // CompressedClassSpaceSize is the size, in bytes, of the address range we
   //  pre-reserve for the compressed class space (if we use class space).
@@ -626,8 +625,7 @@ void Metaspace::ergo_initialize() {
   // We still adjust CompressedClassSpaceSize to reasonable limits, mainly to
   //  save on reserved space, and to make ergnonomics less confusing.
 
-  // (aligned just for cleanliness:)
-  MaxMetaspaceSize = MAX2(align_down(MaxMetaspaceSize, commit_alignment()), commit_alignment());
+  MaxMetaspaceSize = MAX2(MaxMetaspaceSize, commit_alignment());
 
   if (UseCompressedClassPointers) {
     // Let CCS size not be larger than 80% of MaxMetaspaceSize. Note that is

src/hotspot/share/memory/metaspace/metaspaceReporter.cpp

@@ -96,10 +96,7 @@ static void print_vs(outputStream* out, size_t scale) {
 
 static void print_settings(outputStream* out, size_t scale) {
   out->print("MaxMetaspaceSize: ");
-  // See Metaspace::ergo_initialize() for how MaxMetaspaceSize is rounded
-  if (MaxMetaspaceSize >= align_down(max_uintx, Metaspace::commit_alignment())) {
-    // aka "very big". Default is max_uintx, but due to rounding in arg parsing the real
-    // value is smaller.
+  if (MaxMetaspaceSize == max_uintx) {
     out->print("unlimited");
   } else {
     print_human_readable_size(out, MaxMetaspaceSize, scale);