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*
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* version 2 for more details (a copy is included in the LICENSE file that
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*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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import java.util.concurrent.TimeoutException;
import sun.hotspot.WhiteBox;
/*
* @test TestStressRSetCoarsening.java
* @key stress
* @bug 8146984 8147087
* @requires vm.gc=="G1" | vm.gc=="null"
* @requires os.maxMemory > 3G
*
* @summary Stress G1 Remembered Set by creating a lot of cross region links
* @modules java.base/sun.misc
* @library /testlibrary /test/lib
* @build sun.hotspot.WhiteBox
* @run main ClassFileInstaller sun.hotspot.WhiteBox
* sun.hotspot.WhiteBox$WhiteBoxPermission
* @run main/othervm/timeout=300
* -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:+UseG1GC
* -XX:+IgnoreUnrecognizedVMOptions -XX:+PrintGC -XX:+PrintGCTimeStamps -Xlog:gc
* -Xmx500m -XX:G1HeapRegionSize=1m -XX:MaxGCPauseMillis=1000 TestStressRSetCoarsening 1 0 300
* @run main/othervm/timeout=300
* -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:+UseG1GC
* -XX:+IgnoreUnrecognizedVMOptions -XX:+PrintGC -XX:+PrintGCTimeStamps -Xlog:gc
* -Xmx500m -XX:G1HeapRegionSize=8m -XX:MaxGCPauseMillis=1000 TestStressRSetCoarsening 1 10 300
* @run main/othervm/timeout=300
* -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:+UseG1GC
* -XX:+IgnoreUnrecognizedVMOptions -XX:+PrintGC -XX:+PrintGCTimeStamps -Xlog:gc
* -Xmx500m -XX:G1HeapRegionSize=32m -XX:MaxGCPauseMillis=1000 TestStressRSetCoarsening 42 10 300
* @run main/othervm/timeout=300
* -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:+UseG1GC
* -XX:+IgnoreUnrecognizedVMOptions -XX:+PrintGC -XX:+PrintGCTimeStamps -Xlog:gc
* -Xmx500m -XX:G1HeapRegionSize=1m -XX:MaxGCPauseMillis=1000 TestStressRSetCoarsening 2 0 300
* @run main/othervm/timeout=1800
* -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:+UseG1GC
* -XX:+IgnoreUnrecognizedVMOptions -XX:+PrintGC -XX:+PrintGCTimeStamps -Xlog:gc
* -Xmx1G -XX:G1HeapRegionSize=1m -XX:MaxGCPauseMillis=1000 TestStressRSetCoarsening 500 0 1800
* @run main/othervm/timeout=1800
* -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:+UseG1GC
* -XX:+IgnoreUnrecognizedVMOptions -XX:+PrintGC -XX:+PrintGCTimeStamps -Xlog:gc
* -Xmx1G -XX:G1HeapRegionSize=1m -XX:MaxGCPauseMillis=1000 TestStressRSetCoarsening 10 10 1800
*/
/**
* What the test does.
* Preparation stage:
* Fill out ~90% of the heap with objects, each object is an object array.
* If we want to allocate K objects per region, we calculate N to meet:
* sizeOf(Object[N]) ~= regionSize / K
* Stress stage:
* No more allocation, so no more GC.
* We will perform a number of iterations. On each iteration i,
* for each pair of regions Rx and Ry we will set c[i] references
* from Rx to Ry. If c[i] less than c[i-1] at the end of iteration
* concurrent mark cycle will be initiated (to recalculate remembered sets).
* As the result RSet will be growing up and down, up and down many times.
*
* The test expects: no crash and no timeouts.
*
* Test Parameters:
* args[0] - number of objects per Heap Region (1 - means humongous)
* args[1] - number of regions to refresh to provoke GC at the end of cycle.
* (0 - means no GC, i.e. no reading from RSet)
* args[2] - timeout in seconds (to stop execution to avoid jtreg timeout)
*/
public class TestStressRSetCoarsening {
public static void main(String... args) throws InterruptedException {
if (args.length != 3) {
throw new IllegalArgumentException("Wrong number of arguments " + args.length);
}
int objectsPerRegion = Integer.parseInt(args[0]); // 1 means humongous
int regsToRefresh = Integer.parseInt(args[1]); // 0 means no regions to refresh at the end of cycle
int timeout = Integer.parseInt(args[2]); // in seconds, test should stop working eariler
new TestStressRSetCoarsening(objectsPerRegion, regsToRefresh, timeout).go();
}
private static final long KB = 1024;
private static final long MB = 1024 * KB;
private static final WhiteBox WB = WhiteBox.getWhiteBox();
public final Object[][] storage;
/**
* Number of objects per region. This is a test parameter.
*/
public final int K;
/**
* Length of object array: sizeOf(Object[N]) ~= regionSize / K
* N will be calculated as function of K.
*/
public final int N;
/**
* How many regions involved into testing.
* Will be calculated as heapFractionToAllocate * freeRegionCount.
*/
public final int regionCount;
/**
* How much heap to use.
*/
public final float heapFractionToAllocate = 0.9f;
/**
* How many regions to be refreshed at the end of cycle.
* This is a test parameter.
*/
public final int regsToRefresh;
/**
* Initial time.
*/
public final long start;
/**
* Time when the test should stop working.
*/
public final long finishAt;
/**
* Does pre-calculation and allocate necessary objects.
*
* @param objPerRegions how many objects per G1 heap region
*/
TestStressRSetCoarsening(int objPerRegions, int regsToRefresh, int timeout) {
this.K = objPerRegions;
this.regsToRefresh = regsToRefresh;
this.start = System.currentTimeMillis();
this.finishAt = start + timeout * 900; // 10% ahead of jtreg timeout
long regionSize = WB.g1RegionSize();
// How many free regions
Runtime rt = Runtime.getRuntime();
long used = rt.totalMemory() - rt.freeMemory();
long totalFree = rt.maxMemory() - used;
regionCount = (int) ((totalFree / regionSize) * heapFractionToAllocate);
long toAllocate = regionCount * regionSize;
System.out.println("%% Test parameters");
System.out.println("%% Objects per region : " + K);
System.out.println("%% Heap fraction to allocate : " + (int) (heapFractionToAllocate * 100) + "%");
System.out.println("%% Regions to refresh to provoke GC: " + regsToRefresh);
System.out.println("%% Memory");
System.out.println("%% used : " + used / MB + "M");
System.out.println("%% available : " + totalFree / MB + "M");
System.out.println("%% to allocate : " + toAllocate / MB + "M");
System.out.println("%% (in regs) : " + regionCount);
System.out.println("%% G1 Region Size: " + regionSize / MB + "M");
int refSize = WB.getHeapOopSize();
// Calculate N: K*sizeOf(Object[N]) ~= regionSize
// sizeOf(Object[N]) ~= (N+4)*refSize
// ==>
// N = regionSize / K / refSize - 4;
N = (int) ((regionSize / K) / refSize) - 5;
/*
* --------------
* region0 storage[0] = new Object[N]
* ...
* storage[K-1] = new Object[N]
* ---------------
* region1 storage[K] = new Object[N]
* ...
* storage[2*K - 1] = new Object[N]
* --------------
* ...
* --------------
* regionX storage[X*K] = new Object[N]
* ...
* storage[(X+1)*K -1] = new Object[N]
* where X = HeapFraction * TotalRegions
* -------------
*/
System.out.println("%% Objects");
System.out.println("%% N (array length) : " + N);
System.out.println("%% K (objects in regions): " + K);
System.out.println("%% Reference size : " + refSize);
System.out.println("%% Approximate obj size : " + (N + 2) * refSize / KB + "K)");
storage = new Object[regionCount * K][];
for (int i = 0; i < storage.length; i++) {
storage[i] = new Object[N];
}
}
public void go() throws InterruptedException {
// threshold for sparce -> fine
final int FINE = WB.getIntxVMFlag("G1RSetSparseRegionEntries").intValue();
// threshold for fine -> coarse
final int COARSE = WB.getIntxVMFlag("G1RSetRegionEntries").intValue();
// regToRegRefCounts - array of reference counts from region to region
// at the the end of iteration.
// The number of test iterations is array length - 1.
// If c[i] > c[i-1] then during the iteration i more references will
// be created.
// If c[i] < c[i-1] then some referenes will be cleaned.
int[] regToRegRefCounts = {0, FINE / 2, 0, FINE, (FINE + COARSE) / 2, 0,
COARSE, COARSE + 10, FINE + 1, FINE / 2, 0};
// For progress tracking
int[] progress = new int[regToRegRefCounts.length];
progress[0] = 0;
for (int i = 1; i < regToRegRefCounts.length; i++) {
progress[i] = progress[i - 1] + Math.abs(regToRegRefCounts[i] - regToRegRefCounts[i - 1]);
}
try {
for (int i = 1; i < regToRegRefCounts.length; i++) {
int pre = regToRegRefCounts[i - 1];
int cur = regToRegRefCounts[i];
float prog = ((float) progress[i - 1] / progress[progress.length - 1]);
System.out.println("%% step " + i
+ " out of " + (regToRegRefCounts.length - 1)
+ " (~" + (int) (100 * prog) + "% done)");
System.out.println("%% " + pre + " --> " + cur);
for (int to = 0; to < regionCount; to++) {
// Select a celebrity object that we will install references to.
// The celebrity will be referred from all other regions.
// If the number of references after should be less than they
// were before, select NULL.
Object celebrity = cur > pre ? storage[to * K] : null;
for (int from = 0; from < regionCount; from++) {
if (to == from) {
continue; // no need to refer to itself
}
int step = cur > pre ? +1 : -1;
for (int rn = pre; rn != cur; rn += step) {
storage[getY(to, from, rn)][getX(to, from, rn)] = celebrity;
if (System.currentTimeMillis() > finishAt) {
throw new TimeoutException();
}
}
}
}
if (pre > cur) {
// Number of references went down.
// Need to provoke recalculation of RSet.
WB.g1StartConcMarkCycle();
while (WB.g1InConcurrentMark()) {
Thread.sleep(1);
}
}
// To force the use of rememebered set entries we need to provoke a GC.
// To induce some fragmentation, and some mixed GCs, we need
// to make a few objects unreachable.
for (int toClean = i * regsToRefresh; toClean < (i + 1) * regsToRefresh; toClean++) {
int to = toClean % regionCount;
// Need to remove all references from all regions to the region 'to'
for (int from = 0; from < regionCount; from++) {
if (to == from) {
continue; // no need to refer to itself
}
for (int rn = 0; rn <= cur; rn++) {
storage[getY(to, from, rn)][getX(to, from, rn)] = null;
}
}
// 'Refresh' storage elements for the region 'to'
// After that loop all 'old' objects in the region 'to'
// should become unreachable.
for (int k = 0; k < K; k++) {
storage[(to * K + k) % storage.length] = new Object[N];
}
}
}
} catch (TimeoutException e) {
System.out.println("%% TIMEOUT!!!");
}
long now = System.currentTimeMillis();
System.out.println("%% Summary");
System.out.println("%% Time spent : " + ((now - start) / 1000) + " seconds");
System.out.println("%% Free memory left : " + Runtime.getRuntime().freeMemory() / KB + "K");
System.out.println("%% Test passed");
}
/**
* Returns X index in the Storage of the reference #rn from the region
* 'from' to the region 'to'.
*
* @param to region # to refer to
* @param from region # to refer from
* @param rn number of reference
*
* @return X index in the range: [0 ... N-1]
*/
private int getX(int to, int from, int rn) {
return (rn * regionCount + to) % N;
}
/**
* Returns Y index in the Storage of the reference #rn from the region
* 'from' to the region 'to'.
*
* @param to region # to refer to
* @param from region # to refer from
* @param rn number of reference
*
* @return Y index in the range: [0 ... K*regionCount -1]
*/
private int getY(int to, int from, int rn) {
return ((rn * regionCount + to) / N + from * K) % (regionCount * K);
}
}