8028391: Make the Min/MaxHeapFreeRatio flags manageable
Summary: Made the flags Min- and MaxHeapFreeRatio manageable, and implemented support for these flags in ParallalGC.
Reviewed-by: sla, mgerdin, brutisso
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Wed Jan 29 23:17:05 2014 +0100
@@ -1575,8 +1575,6 @@
void
G1CollectedHeap::
resize_if_necessary_after_full_collection(size_t word_size) {
- assert(MinHeapFreeRatio <= MaxHeapFreeRatio, "sanity check");
-
// Include the current allocation, if any, and bytes that will be
// pre-allocated to support collections, as "used".
const size_t used_after_gc = used();
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp Wed Jan 29 23:17:05 2014 +0100
@@ -23,6 +23,7 @@
*/
#include "precompiled.hpp"
+#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
#include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp"
#include "gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp"
#include "gc_implementation/parallelScavenge/psScavenge.hpp"
@@ -76,6 +77,38 @@
_old_gen_policy_is_ready = false;
}
+size_t PSAdaptiveSizePolicy::calculate_free_based_on_live(size_t live, uintx ratio_as_percentage) {
+ // We want to calculate how much free memory there can be based on the
+ // amount of live data currently in the old gen. Using the formula:
+ // ratio * (free + live) = free
+ // Some equation solving later we get:
+ // free = (live * ratio) / (1 - ratio)
+
+ const double ratio = ratio_as_percentage / 100.0;
+ const double ratio_inverse = 1.0 - ratio;
+ const double tmp = live * ratio;
+ size_t free = (size_t)(tmp / ratio_inverse);
+
+ return free;
+}
+
+size_t PSAdaptiveSizePolicy::calculated_old_free_size_in_bytes() const {
+ size_t free_size = (size_t)(_promo_size + avg_promoted()->padded_average());
+ size_t live = ParallelScavengeHeap::heap()->old_gen()->used_in_bytes();
+
+ if (MinHeapFreeRatio != 0) {
+ size_t min_free = calculate_free_based_on_live(live, MinHeapFreeRatio);
+ free_size = MAX2(free_size, min_free);
+ }
+
+ if (MaxHeapFreeRatio != 100) {
+ size_t max_free = calculate_free_based_on_live(live, MaxHeapFreeRatio);
+ free_size = MIN2(max_free, free_size);
+ }
+
+ return free_size;
+}
+
void PSAdaptiveSizePolicy::major_collection_begin() {
// Update the interval time
_major_timer.stop();
@@ -1292,3 +1325,18 @@
st,
PSScavenge::tenuring_threshold());
}
+
+#ifndef PRODUCT
+
+void TestOldFreeSpaceCalculation_test() {
+ assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 20) == 25, "Calculation of free memory failed");
+ assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 50) == 100, "Calculation of free memory failed");
+ assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 60) == 150, "Calculation of free memory failed");
+ assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 75) == 300, "Calculation of free memory failed");
+ assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 20) == 100, "Calculation of free memory failed");
+ assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 50) == 400, "Calculation of free memory failed");
+ assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 60) == 600, "Calculation of free memory failed");
+ assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 75) == 1200, "Calculation of free memory failed");
+}
+
+#endif /* !PRODUCT */
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp Wed Jan 29 23:17:05 2014 +0100
@@ -240,7 +240,6 @@
void major_collection_begin();
void major_collection_end(size_t amount_live, GCCause::Cause gc_cause);
- //
void tenured_allocation(size_t size) {
_avg_pretenured->sample(size);
}
@@ -248,9 +247,9 @@
// Accessors
// NEEDS_CLEANUP should use sizes.hpp
- size_t calculated_old_free_size_in_bytes() const {
- return (size_t)(_promo_size + avg_promoted()->padded_average());
- }
+ static size_t calculate_free_based_on_live(size_t live, uintx ratio_as_percentage);
+
+ size_t calculated_old_free_size_in_bytes() const;
size_t average_old_live_in_bytes() const {
return (size_t) avg_old_live()->average();
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp Wed Jan 29 23:17:05 2014 +0100
@@ -529,8 +529,19 @@
counters->update_survivor_overflowed(_survivor_overflow);
}
+ size_t max_young_size = young_gen->max_size();
+
+ // Deciding a free ratio in the young generation is tricky, so if
+ // MinHeapFreeRatio or MaxHeapFreeRatio are in use (implicating
+ // that the old generation size may have been limited because of them) we
+ // should then limit our young generation size using NewRatio to have it
+ // follow the old generation size.
+ if (MinHeapFreeRatio != 0 || MaxHeapFreeRatio != 100) {
+ max_young_size = MIN2(old_gen->capacity_in_bytes() / NewRatio, young_gen->max_size());
+ }
+
size_t survivor_limit =
- size_policy->max_survivor_size(young_gen->max_size());
+ size_policy->max_survivor_size(max_young_size);
_tenuring_threshold =
size_policy->compute_survivor_space_size_and_threshold(
_survivor_overflow,
@@ -553,8 +564,7 @@
// Do call at minor collections?
// Don't check if the size_policy is ready at this
// level. Let the size_policy check that internally.
- if (UseAdaptiveSizePolicy &&
- UseAdaptiveGenerationSizePolicyAtMinorCollection &&
+ if (UseAdaptiveGenerationSizePolicyAtMinorCollection &&
((gc_cause != GCCause::_java_lang_system_gc) ||
UseAdaptiveSizePolicyWithSystemGC)) {
@@ -568,7 +578,7 @@
size_t eden_live = young_gen->eden_space()->used_in_bytes();
size_t cur_eden = young_gen->eden_space()->capacity_in_bytes();
size_t max_old_gen_size = old_gen->max_gen_size();
- size_t max_eden_size = young_gen->max_size() -
+ size_t max_eden_size = max_young_size -
young_gen->from_space()->capacity_in_bytes() -
young_gen->to_space()->capacity_in_bytes();
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/psYoungGen.hpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psYoungGen.hpp Wed Jan 29 23:17:05 2014 +0100
@@ -127,7 +127,7 @@
void adjust_pointers();
void compact();
- // Called during/after gc
+ // Called during/after GC
void swap_spaces();
// Resize generation using suggested free space size and survivor size
@@ -146,14 +146,14 @@
size_t free_in_words() const;
// The max this generation can grow to
- size_t max_size() const { return _reserved.byte_size(); }
+ size_t max_size() const { return _reserved.byte_size(); }
// The max this generation can grow to if the boundary between
// the generations are allowed to move.
size_t gen_size_limit() const { return _max_gen_size; }
bool is_maximal_no_gc() const {
- return true; // never expands except at a GC
+ return true; // Never expands except at a GC
}
// Allocation
--- a/hotspot/src/share/vm/prims/jni.cpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/prims/jni.cpp Wed Jan 29 23:17:05 2014 +0100
@@ -5061,6 +5061,7 @@
void TestMetaspaceAux_test();
void TestMetachunk_test();
void TestVirtualSpaceNode_test();
+void TestOldFreeSpaceCalculation_test();
#if INCLUDE_ALL_GCS
void TestG1BiasedArray_test();
#endif
@@ -5081,6 +5082,7 @@
run_unit_test(QuickSort::test_quick_sort());
run_unit_test(AltHashing::test_alt_hash());
run_unit_test(test_loggc_filename());
+ run_unit_test(TestOldFreeSpaceCalculation_test());
#if INCLUDE_VM_STRUCTS
run_unit_test(VMStructs::test());
#endif
--- a/hotspot/src/share/vm/runtime/arguments.cpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/runtime/arguments.cpp Wed Jan 29 23:17:05 2014 +0100
@@ -1569,6 +1569,16 @@
vm_exit(1);
}
+ if (UseAdaptiveSizePolicy) {
+ // We don't want to limit adaptive heap sizing's freedom to adjust the heap
+ // unless the user actually sets these flags.
+ if (FLAG_IS_DEFAULT(MinHeapFreeRatio)) {
+ FLAG_SET_DEFAULT(MinHeapFreeRatio, 0);
+ }
+ if (FLAG_IS_DEFAULT(MaxHeapFreeRatio)) {
+ FLAG_SET_DEFAULT(MaxHeapFreeRatio, 100);
+ }
+ }
// If InitialSurvivorRatio or MinSurvivorRatio were not specified, but the
// SurvivorRatio has been set, reset their default values to SurvivorRatio +
@@ -1844,7 +1854,7 @@
}
bool Arguments::verify_percentage(uintx value, const char* name) {
- if (value <= 100) {
+ if (is_percentage(value)) {
return true;
}
jio_fprintf(defaultStream::error_stream(),
@@ -1932,6 +1942,34 @@
return count_p < 2 && count_t < 2;
}
+bool Arguments::verify_MinHeapFreeRatio(FormatBuffer<80>& err_msg, uintx min_heap_free_ratio) {
+ if (!is_percentage(min_heap_free_ratio)) {
+ err_msg.print("MinHeapFreeRatio must have a value between 0 and 100");
+ return false;
+ }
+ if (min_heap_free_ratio > MaxHeapFreeRatio) {
+ err_msg.print("MinHeapFreeRatio (" UINTX_FORMAT ") must be less than or "
+ "equal to MaxHeapFreeRatio (" UINTX_FORMAT ")", min_heap_free_ratio,
+ MaxHeapFreeRatio);
+ return false;
+ }
+ return true;
+}
+
+bool Arguments::verify_MaxHeapFreeRatio(FormatBuffer<80>& err_msg, uintx max_heap_free_ratio) {
+ if (!is_percentage(max_heap_free_ratio)) {
+ err_msg.print("MaxHeapFreeRatio must have a value between 0 and 100");
+ return false;
+ }
+ if (max_heap_free_ratio < MinHeapFreeRatio) {
+ err_msg.print("MaxHeapFreeRatio (" UINTX_FORMAT ") must be greater than or "
+ "equal to MinHeapFreeRatio (" UINTX_FORMAT ")", max_heap_free_ratio,
+ MinHeapFreeRatio);
+ return false;
+ }
+ return true;
+}
+
// Check consistency of GC selection
bool Arguments::check_gc_consistency() {
check_gclog_consistency();
@@ -2037,8 +2075,6 @@
status = status && verify_interval(AdaptiveSizePolicyWeight, 0, 100,
"AdaptiveSizePolicyWeight");
status = status && verify_percentage(ThresholdTolerance, "ThresholdTolerance");
- status = status && verify_percentage(MinHeapFreeRatio, "MinHeapFreeRatio");
- status = status && verify_percentage(MaxHeapFreeRatio, "MaxHeapFreeRatio");
// Divide by bucket size to prevent a large size from causing rollover when
// calculating amount of memory needed to be allocated for the String table.
@@ -2048,15 +2084,19 @@
status = status && verify_interval(SymbolTableSize, minimumSymbolTableSize,
(max_uintx / SymbolTable::bucket_size()), "SymbolTable size");
- if (MinHeapFreeRatio > MaxHeapFreeRatio) {
- jio_fprintf(defaultStream::error_stream(),
- "MinHeapFreeRatio (" UINTX_FORMAT ") must be less than or "
- "equal to MaxHeapFreeRatio (" UINTX_FORMAT ")\n",
- MinHeapFreeRatio, MaxHeapFreeRatio);
- status = false;
+ {
+ // Using "else if" below to avoid printing two error messages if min > max.
+ // This will also prevent us from reporting both min>100 and max>100 at the
+ // same time, but that is less annoying than printing two identical errors IMHO.
+ FormatBuffer<80> err_msg("");
+ if (!verify_MinHeapFreeRatio(err_msg, MinHeapFreeRatio)) {
+ jio_fprintf(defaultStream::error_stream(), "%s\n", err_msg.buffer());
+ status = false;
+ } else if (!verify_MaxHeapFreeRatio(err_msg, MaxHeapFreeRatio)) {
+ jio_fprintf(defaultStream::error_stream(), "%s\n", err_msg.buffer());
+ status = false;
+ }
}
- // Keeping the heap 100% free is hard ;-) so limit it to 99%.
- MinHeapFreeRatio = MIN2(MinHeapFreeRatio, (uintx) 99);
// Min/MaxMetaspaceFreeRatio
status = status && verify_percentage(MinMetaspaceFreeRatio, "MinMetaspaceFreeRatio");
@@ -2689,7 +2729,7 @@
} else if (match_option(option, "-Xmaxf", &tail)) {
char* err;
int maxf = (int)(strtod(tail, &err) * 100);
- if (*err != '\0' || maxf < 0 || maxf > 100) {
+ if (*err != '\0' || *tail == '\0' || maxf < 0 || maxf > 100) {
jio_fprintf(defaultStream::error_stream(),
"Bad max heap free percentage size: %s\n",
option->optionString);
@@ -2701,7 +2741,7 @@
} else if (match_option(option, "-Xminf", &tail)) {
char* err;
int minf = (int)(strtod(tail, &err) * 100);
- if (*err != '\0' || minf < 0 || minf > 100) {
+ if (*err != '\0' || *tail == '\0' || minf < 0 || minf > 100) {
jio_fprintf(defaultStream::error_stream(),
"Bad min heap free percentage size: %s\n",
option->optionString);
@@ -3646,9 +3686,9 @@
// Set per-collector flags
if (UseParallelGC || UseParallelOldGC) {
set_parallel_gc_flags();
- } else if (UseConcMarkSweepGC) { // should be done before ParNew check below
+ } else if (UseConcMarkSweepGC) { // Should be done before ParNew check below
set_cms_and_parnew_gc_flags();
- } else if (UseParNewGC) { // skipped if CMS is set above
+ } else if (UseParNewGC) { // Skipped if CMS is set above
set_parnew_gc_flags();
} else if (UseG1GC) {
set_g1_gc_flags();
@@ -3662,6 +3702,10 @@
" using -XX:ParallelGCThreads=N");
}
}
+ if (MinHeapFreeRatio == 100) {
+ // Keeping the heap 100% free is hard ;-) so limit it to 99%.
+ FLAG_SET_ERGO(uintx, MinHeapFreeRatio, 99);
+ }
#else // INCLUDE_ALL_GCS
assert(verify_serial_gc_flags(), "SerialGC unset");
#endif // INCLUDE_ALL_GCS
--- a/hotspot/src/share/vm/runtime/arguments.hpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/runtime/arguments.hpp Wed Jan 29 23:17:05 2014 +0100
@@ -27,6 +27,7 @@
#include "runtime/java.hpp"
#include "runtime/perfData.hpp"
+#include "utilities/debug.hpp"
#include "utilities/top.hpp"
// Arguments parses the command line and recognizes options
@@ -370,11 +371,16 @@
static jint parse_vm_init_args(const JavaVMInitArgs* args);
static jint parse_each_vm_init_arg(const JavaVMInitArgs* args, SysClassPath* scp_p, bool* scp_assembly_required_p, Flag::Flags origin);
static jint finalize_vm_init_args(SysClassPath* scp_p, bool scp_assembly_required);
- static bool is_bad_option(const JavaVMOption* option, jboolean ignore,
- const char* option_type);
+ static bool is_bad_option(const JavaVMOption* option, jboolean ignore, const char* option_type);
+
static bool is_bad_option(const JavaVMOption* option, jboolean ignore) {
return is_bad_option(option, ignore, NULL);
}
+
+ static bool is_percentage(uintx val) {
+ return val <= 100;
+ }
+
static bool verify_interval(uintx val, uintx min,
uintx max, const char* name);
static bool verify_min_value(intx val, intx min, const char* name);
@@ -440,6 +446,15 @@
static jint apply_ergo();
// Adjusts the arguments after the OS have adjusted the arguments
static jint adjust_after_os();
+
+ // Verifies that the given value will fit as a MinHeapFreeRatio. If not, an error
+ // message is returned in the provided buffer.
+ static bool verify_MinHeapFreeRatio(FormatBuffer<80>& err_msg, uintx min_heap_free_ratio);
+
+ // Verifies that the given value will fit as a MaxHeapFreeRatio. If not, an error
+ // message is returned in the provided buffer.
+ static bool verify_MaxHeapFreeRatio(FormatBuffer<80>& err_msg, uintx max_heap_free_ratio);
+
// Check for consistency in the selection of the garbage collector.
static bool check_gc_consistency();
static void check_deprecated_gcs();
--- a/hotspot/src/share/vm/runtime/globals.hpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/runtime/globals.hpp Wed Jan 29 23:17:05 2014 +0100
@@ -3135,15 +3135,15 @@
"Maximum size of class area in Metaspace when compressed " \
"class pointers are used") \
\
- product(uintx, MinHeapFreeRatio, 40, \
+ manageable(uintx, MinHeapFreeRatio, 40, \
"The minimum percentage of heap free after GC to avoid expansion."\
- " For most GCs this applies to the old generation. In G1 it" \
- " applies to the whole heap. Not supported by ParallelGC.") \
- \
- product(uintx, MaxHeapFreeRatio, 70, \
+ " For most GCs this applies to the old generation. In G1 and" \
+ " ParallelGC it applies to the whole heap.") \
+ \
+ manageable(uintx, MaxHeapFreeRatio, 70, \
"The maximum percentage of heap free after GC to avoid shrinking."\
- " For most GCs this applies to the old generation. In G1 it" \
- " applies to the whole heap. Not supported by ParallelGC.") \
+ " For most GCs this applies to the old generation. In G1 and" \
+ " ParallelGC it applies to the whole heap.") \
\
product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
"Number of milliseconds per MB of free space in the heap") \
--- a/hotspot/src/share/vm/services/attachListener.cpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/services/attachListener.cpp Wed Jan 29 23:17:05 2014 +0100
@@ -282,6 +282,20 @@
return JNI_ERR;
}
}
+
+ if (strncmp(name, "MaxHeapFreeRatio", 17) == 0) {
+ FormatBuffer<80> err_msg("");
+ if (!Arguments::verify_MaxHeapFreeRatio(err_msg, value)) {
+ out->print_cr(err_msg.buffer());
+ return JNI_ERR;
+ }
+ } else if (strncmp(name, "MinHeapFreeRatio", 17) == 0) {
+ FormatBuffer<80> err_msg("");
+ if (!Arguments::verify_MinHeapFreeRatio(err_msg, value)) {
+ out->print_cr(err_msg.buffer());
+ return JNI_ERR;
+ }
+ }
bool res = CommandLineFlags::uintxAtPut((char*)name, &value, Flag::ATTACH_ON_DEMAND);
if (! res) {
out->print_cr("setting flag %s failed", name);
--- a/hotspot/src/share/vm/services/management.cpp Wed Jan 15 07:20:04 2014 -0800
+++ b/hotspot/src/share/vm/services/management.cpp Wed Jan 29 23:17:05 2014 +0100
@@ -1833,6 +1833,18 @@
succeed = CommandLineFlags::intxAtPut(name, &ivalue, Flag::MANAGEMENT);
} else if (flag->is_uintx()) {
uintx uvalue = (uintx)new_value.j;
+
+ if (strncmp(name, "MaxHeapFreeRatio", 17) == 0) {
+ FormatBuffer<80> err_msg("");
+ if (!Arguments::verify_MaxHeapFreeRatio(err_msg, uvalue)) {
+ THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), err_msg.buffer());
+ }
+ } else if (strncmp(name, "MinHeapFreeRatio", 17) == 0) {
+ FormatBuffer<80> err_msg("");
+ if (!Arguments::verify_MinHeapFreeRatio(err_msg, uvalue)) {
+ THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), err_msg.buffer());
+ }
+ }
succeed = CommandLineFlags::uintxAtPut(name, &uvalue, Flag::MANAGEMENT);
} else if (flag->is_uint64_t()) {
uint64_t uvalue = (uint64_t)new_value.j;