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8376626: Shenandoah: Remove command line options for setting min and max region sizes #528

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8376626: Shenandoah: Remove command line options for setting min and max region sizes #528

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3 changes: 2 additions & 1 deletion src/hotspot/share/gc/shenandoah/shenandoahArguments.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -205,7 +205,8 @@ void ShenandoahArguments::initialize() {
}

size_t ShenandoahArguments::conservative_max_heap_alignment() {
size_t align = next_power_of_2(ShenandoahMaxRegionSize);
static_assert(is_power_of_2(ShenandoahHeapRegion::MAX_REGION_SIZE), "Max region size must be a power of 2.");
size_t align = ShenandoahHeapRegion::MAX_REGION_SIZE;
if (UseLargePages) {
align = MAX2(align, os::large_page_size());
}
Expand Down
53 changes: 6 additions & 47 deletions src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.cpp
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Expand Up @@ -650,61 +650,20 @@ size_t ShenandoahHeapRegion::block_size(const HeapWord* p) const {
}

size_t ShenandoahHeapRegion::setup_sizes(size_t max_heap_size) {
// Absolute minimums we should not ever break.
static const size_t MIN_REGION_SIZE = 256*K;

if (FLAG_IS_DEFAULT(ShenandoahMinRegionSize)) {
FLAG_SET_DEFAULT(ShenandoahMinRegionSize, MIN_REGION_SIZE);
}

// Generational Shenandoah needs this alignment for card tables.
if (strcmp(ShenandoahGCMode, "generational") == 0) {
max_heap_size = align_up(max_heap_size , CardTable::ct_max_alignment_constraint());
}

size_t region_size;
if (FLAG_IS_DEFAULT(ShenandoahRegionSize)) {
if (ShenandoahMinRegionSize > max_heap_size / MIN_NUM_REGIONS) {
err_msg message("Max heap size (%zu%s) is too low to afford the minimum number "
"of regions (%zu) of minimum region size (%zu%s).",
byte_size_in_proper_unit(max_heap_size), proper_unit_for_byte_size(max_heap_size),
MIN_NUM_REGIONS,
byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize));
vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize option", message);
}
if (ShenandoahMinRegionSize < MIN_REGION_SIZE) {
err_msg message("%zu%s should not be lower than minimum region size (%zu%s).",
byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize),
byte_size_in_proper_unit(MIN_REGION_SIZE), proper_unit_for_byte_size(MIN_REGION_SIZE));
vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize option", message);
}
if (ShenandoahMinRegionSize < MinTLABSize) {
err_msg message("%zu%s should not be lower than TLAB size size (%zu%s).",
byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize),
byte_size_in_proper_unit(MinTLABSize), proper_unit_for_byte_size(MinTLABSize));
vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize option", message);
}
if (ShenandoahMaxRegionSize < MIN_REGION_SIZE) {
err_msg message("%zu%s should not be lower than min region size (%zu%s).",
byte_size_in_proper_unit(ShenandoahMaxRegionSize), proper_unit_for_byte_size(ShenandoahMaxRegionSize),
byte_size_in_proper_unit(MIN_REGION_SIZE), proper_unit_for_byte_size(MIN_REGION_SIZE));
vm_exit_during_initialization("Invalid -XX:ShenandoahMaxRegionSize option", message);
}
if (ShenandoahMinRegionSize > ShenandoahMaxRegionSize) {
err_msg message("Minimum (%zu%s) should be larger than maximum (%zu%s).",
byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize),
byte_size_in_proper_unit(ShenandoahMaxRegionSize), proper_unit_for_byte_size(ShenandoahMaxRegionSize));
vm_exit_during_initialization("Invalid -XX:ShenandoahMinRegionSize or -XX:ShenandoahMaxRegionSize", message);
}

// We rapidly expand to max_heap_size in most scenarios, so that is the measure
// for usual heap sizes. Do not depend on initial_heap_size here.
region_size = max_heap_size / ShenandoahTargetNumRegions;

// Now make sure that we don't go over or under our limits.
region_size = MAX2(ShenandoahMinRegionSize, region_size);
region_size = MIN2(ShenandoahMaxRegionSize, region_size);

region_size = MAX2(MIN_REGION_SIZE, region_size);
region_size = MIN2(MAX_REGION_SIZE, region_size);
} else {
if (ShenandoahRegionSize > max_heap_size / MIN_NUM_REGIONS) {
err_msg message("Max heap size (%zu%s) is too low to afford the minimum number "
Expand All @@ -714,16 +673,16 @@ size_t ShenandoahHeapRegion::setup_sizes(size_t max_heap_size) {
byte_size_in_proper_unit(ShenandoahRegionSize), proper_unit_for_byte_size(ShenandoahRegionSize));
vm_exit_during_initialization("Invalid -XX:ShenandoahRegionSize option", message);
}
if (ShenandoahRegionSize < ShenandoahMinRegionSize) {
if (ShenandoahRegionSize < MIN_REGION_SIZE) {
err_msg message("Heap region size (%zu%s) should be larger than min region size (%zu%s).",
byte_size_in_proper_unit(ShenandoahRegionSize), proper_unit_for_byte_size(ShenandoahRegionSize),
byte_size_in_proper_unit(ShenandoahMinRegionSize), proper_unit_for_byte_size(ShenandoahMinRegionSize));
byte_size_in_proper_unit(MIN_REGION_SIZE), proper_unit_for_byte_size(MIN_REGION_SIZE));
vm_exit_during_initialization("Invalid -XX:ShenandoahRegionSize option", message);
}
if (ShenandoahRegionSize > ShenandoahMaxRegionSize) {
if (ShenandoahRegionSize > MAX_REGION_SIZE) {
err_msg message("Heap region size (%zu%s) should be lower than max region size (%zu%s).",
byte_size_in_proper_unit(ShenandoahRegionSize), proper_unit_for_byte_size(ShenandoahRegionSize),
byte_size_in_proper_unit(ShenandoahMaxRegionSize), proper_unit_for_byte_size(ShenandoahMaxRegionSize));
byte_size_in_proper_unit(MAX_REGION_SIZE), proper_unit_for_byte_size(MAX_REGION_SIZE));
vm_exit_during_initialization("Invalid -XX:ShenandoahRegionSize option", message);
}
region_size = ShenandoahRegionSize;
Expand Down
3 changes: 3 additions & 0 deletions src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.hpp
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Expand Up @@ -271,7 +271,10 @@ class ShenandoahHeapRegion {
public:
ShenandoahHeapRegion(HeapWord* start, size_t index, bool committed);

// Absolute minimums and maximums we should not ever break.
static const size_t MIN_NUM_REGIONS = 10;
static const size_t MIN_REGION_SIZE = 256*K;
static const size_t MAX_REGION_SIZE = 32*M;

// Return adjusted max heap size
static size_t setup_sizes(size_t max_heap_size);
Expand Down
8 changes: 0 additions & 8 deletions src/hotspot/share/gc/shenandoah/shenandoah_globals.hpp
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Expand Up @@ -132,14 +132,6 @@
"of regions that would be used, within min/max region size " \
"limits.") \
\
product(size_t, ShenandoahMinRegionSize, 256 * K, EXPERIMENTAL, \
"With automatic region sizing, the regions would be at least " \
"this large.") \
\
product(size_t, ShenandoahMaxRegionSize, 32 * M, EXPERIMENTAL, \
"With automatic region sizing, the regions would be at most " \
"this large.") \
\
product(ccstr, ShenandoahGCMode, "satb", \
"GC mode to use. Among other things, this defines which " \
"barriers are in in use. Possible values are:" \
Expand Down
86 changes: 0 additions & 86 deletions test/hotspot/jtreg/gc/shenandoah/options/TestRegionSizeArgs.java
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Expand Up @@ -38,8 +38,6 @@
public class TestRegionSizeArgs {
public static void main(String[] args) throws Exception {
testInvalidRegionSizes();
testMinRegionSize();
testMaxRegionSize();
}

private static void testInvalidRegionSizes() throws Exception {
Expand Down Expand Up @@ -146,88 +144,4 @@ private static void testInvalidRegionSizes() throws Exception {
output.shouldHaveExitValue(1);
}
}

private static void testMinRegionSize() throws Exception {

{
OutputAnalyzer output = ProcessTools.executeLimitedTestJava("-XX:+UnlockExperimentalVMOptions",
"-XX:+UseShenandoahGC",
"-Xms100m",
"-Xmx1g",
"-XX:ShenandoahMinRegionSize=255K",
"-version");
output.shouldMatch("Invalid -XX:ShenandoahMinRegionSize option");
output.shouldHaveExitValue(1);
}

{
OutputAnalyzer output = ProcessTools.executeLimitedTestJava("-XX:+UnlockExperimentalVMOptions",
"-XX:+UseShenandoahGC",
"-Xms100m",
"-Xmx1g",
"-XX:ShenandoahMinRegionSize=1M",
"-XX:ShenandoahMaxRegionSize=260K",
"-version");
output.shouldMatch("Invalid -XX:ShenandoahMinRegionSize or -XX:ShenandoahMaxRegionSize");
output.shouldHaveExitValue(1);
}
{
OutputAnalyzer output = ProcessTools.executeLimitedTestJava("-XX:+UnlockExperimentalVMOptions",
"-XX:+UseShenandoahGC",
"-Xms100m",
"-Xmx1g",
"-XX:ShenandoahMinRegionSize=200m",
"-version");
output.shouldMatch("Invalid -XX:ShenandoahMinRegionSize option");
output.shouldHaveExitValue(1);
}

{
OutputAnalyzer output = ProcessTools.executeLimitedTestJava("-XX:+UnlockExperimentalVMOptions",
"-XX:+UseShenandoahGC",
"-Xms100m",
"-Xmx1g",
"-XX:ShenandoahMinRegionSize=9m",
"-version");
output.shouldHaveExitValue(0);
}

// This used to assert that _conservative_max_heap_alignment is not a power-of-2.
{
OutputAnalyzer output = ProcessTools.executeLimitedTestJava("-XX:+UnlockExperimentalVMOptions",
"-XX:+UseShenandoahGC",
"-Xms100m",
"-Xmx1g",
"-XX:ShenandoahMaxRegionSize=33m",
"-version");
output.shouldHaveExitValue(0);
}

}

private static void testMaxRegionSize() throws Exception {

{
OutputAnalyzer output = ProcessTools.executeLimitedTestJava("-XX:+UnlockExperimentalVMOptions",
"-XX:+UseShenandoahGC",
"-Xms100m",
"-Xmx1g",
"-XX:ShenandoahMaxRegionSize=255K",
"-version");
output.shouldMatch("Invalid -XX:ShenandoahMaxRegionSize option");
output.shouldHaveExitValue(1);
}

{
OutputAnalyzer output = ProcessTools.executeLimitedTestJava("-XX:+UnlockExperimentalVMOptions",
"-XX:+UseShenandoahGC",
"-Xms100m",
"-Xmx1g",
"-XX:ShenandoahMinRegionSize=1M",
"-XX:ShenandoahMaxRegionSize=260K",
"-version");
output.shouldMatch("Invalid -XX:ShenandoahMinRegionSize or -XX:ShenandoahMaxRegionSize");
output.shouldHaveExitValue(1);
}
}
}