disable jvm balloon

Commit 4bd8720 broke java balloon since it assumes that
page fault path does not modify vma_list hence it is possible to take
vma_list_mutex for read, but this assumption does not hold for java
balloon vma. There is no easy fix for this problem that does not reduce
page fault parallelism. One solution is to take the lock for write during
page fault and downgrade it in vma->fault() handler if possible, but,
in addition to been ugly, this solution will create more contention on
vma_list_mutex that taking it for read.

This patch disables java balloon to unbreak master until satisfactory
solution will be found.

Signed-off-by: Avi Kivity <[email protected]>

java/java.cc

@@ -141,6 +141,7 @@ static int java_main(int argc, char **argv)
     }
 
     size_t auto_heap = 0;
+#if 0
     // Do not use total(), since that won't reflect the whole memory for the
     // machine. It then becomes counterintuitive to tell the user what is the
     // minimum he has to set to balloon
@@ -153,6 +154,7 @@ static int java_main(int argc, char **argv)
         auto_heap <<= 20;
         jvm_heap_size = auto_heap;
     }
+#endif
 
     vm_args.nOptions = options.size();
     vm_args.options = options.data();