Mercurial > hg > graal-compiler
changeset 8845:1b90c7607451
2178143: JVM crashes if the number of bound CPUs changed during runtime
Summary: Supply a new flag -XX:+AssumeMP to workaround the problem. With the flag is turned on, assume VM run on MP platform so is_MP() will return true that sync calls will not skip away.
Reviewed-by: dholmes, acorn, dcubed, jmasa
Contributed-by: yumin.qi@oracle.com
author | minqi |
---|---|
date | Wed, 27 Mar 2013 17:03:19 -0700 |
parents | b601102d00c8 |
children | d7adf726b18a |
files | src/share/vm/runtime/arguments.cpp src/share/vm/runtime/globals.hpp src/share/vm/runtime/os.hpp |
diffstat | 3 files changed, 11 insertions(+), 1 deletions(-) [+] |
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--- a/src/share/vm/runtime/arguments.cpp Wed Mar 27 13:26:44 2013 -0700 +++ b/src/share/vm/runtime/arguments.cpp Wed Mar 27 17:03:19 2013 -0700 @@ -3325,6 +3325,13 @@ } check_deprecated_gcs(); check_deprecated_gc_flags(); + if (AssumeMP && !UseSerialGC) { + if (FLAG_IS_DEFAULT(ParallelGCThreads) && ParallelGCThreads == 1) { + warning("If the number of processors is expected to increase from one, then" + " you should configure the number of parallel GC threads appropriately" + " using -XX:ParallelGCThreads=N"); + } + } #else // INCLUDE_ALL_GCS assert(verify_serial_gc_flags(), "SerialGC unset"); #endif // INCLUDE_ALL_GCS
--- a/src/share/vm/runtime/globals.hpp Wed Mar 27 13:26:44 2013 -0700 +++ b/src/share/vm/runtime/globals.hpp Wed Mar 27 17:03:19 2013 -0700 @@ -457,6 +457,9 @@ lp64_product(intx, ObjectAlignmentInBytes, 8, \ "Default object alignment in bytes, 8 is minimum") \ \ + product(bool, AssumeMP, false, \ + "Instruct the VM to assume multiple processors are available") \ + \ /* UseMembar is theoretically a temp flag used for memory barrier \ * removal testing. It was supposed to be removed before FCS but has \ * been re-added (see 6401008) */ \
--- a/src/share/vm/runtime/os.hpp Wed Mar 27 13:26:44 2013 -0700 +++ b/src/share/vm/runtime/os.hpp Wed Mar 27 17:03:19 2013 -0700 @@ -180,7 +180,7 @@ // Interface for detecting multiprocessor system static inline bool is_MP() { assert(_processor_count > 0, "invalid processor count"); - return _processor_count > 1; + return _processor_count > 1 || AssumeMP; } static julong available_memory(); static julong physical_memory();