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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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/*

 * @test TestLargePageUseForAuxMemory.java

 * @summary Test that auxiliary data structures are allocated using large pages if available.

 * @bug 8058354 8079208

 * @key gc

 * @modules java.base/jdk.internal.misc

 * @library /test/lib

 * @requires vm.gc.G1

 * @build sun.hotspot.WhiteBox

 * @run driver ClassFileInstaller sun.hotspot.WhiteBox

 *                              sun.hotspot.WhiteBox$WhiteBoxPermission

 * @run main/othervm -Xbootclasspath/a:. -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:+IgnoreUnrecognizedVMOptions -XX:+UseLargePages TestLargePageUseForAuxMemory

 */

import java.lang.Math;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import jdk.test.lib.process.OutputAnalyzer;

import jdk.test.lib.process.ProcessTools;

import jdk.test.lib.Asserts;

import jdk.test.lib.Platform;

import sun.hotspot.WhiteBox;

public class TestLargePageUseForAuxMemory {

    static final long HEAP_REGION_SIZE = 1 * 1024 * 1024;

    static long largePageSize;

    static long smallPageSize;

    static long allocGranularity;

    static void checkSize(OutputAnalyzer output, long expectedSize, String pattern) {

        String pageSizeStr = output.firstMatch(pattern, 1);

        if (pageSizeStr == null) {

            output.reportDiagnosticSummary();

            throw new RuntimeException("Match from '" + pattern + "' got 'null' expected: " + expectedSize);

        }

        long size = parseMemoryString(pageSizeStr);

        if (size != expectedSize) {

            output.reportDiagnosticSummary();

            throw new RuntimeException("Match from '" + pattern + "' got " + size + " expected: " + expectedSize);

        }

    }

    static void checkSmallTables(OutputAnalyzer output, long expectedPageSize) throws Exception {

        checkSize(output, expectedPageSize, "Block Offset Table: .*page_size=([^ ]+)");

        checkSize(output, expectedPageSize, "Card Counts Table: .*page_size=([^ ]+)");

    }

    static void checkBitmaps(OutputAnalyzer output, long expectedPageSize) throws Exception {

        checkSize(output, expectedPageSize, "Prev Bitmap: .*page_size=([^ ]+)");

        checkSize(output, expectedPageSize, "Next Bitmap: .*page_size=([^ ]+)");

    }

    static void testVM(String what, long heapsize, boolean cardsShouldUseLargePages, boolean bitmapShouldUseLargePages) throws Exception {

        System.out.println(what + " heapsize " + heapsize + " card table should use large pages " + cardsShouldUseLargePages + " " +

                           "bitmaps should use large pages " + bitmapShouldUseLargePages);

        ProcessBuilder pb;

        // Test with large page enabled.

        pb = ProcessTools.createJavaProcessBuilder("-XX:+UseG1GC",

                                                   "-XX:G1HeapRegionSize=" + HEAP_REGION_SIZE,

                                                   "-Xmx" + heapsize,

                                                   "-Xlog:pagesize",

                                                   "-XX:+UseLargePages",

                                                   "-XX:+IgnoreUnrecognizedVMOptions",  // there is no ObjectAlignmentInBytes in 32 bit builds

                                                   "-XX:ObjectAlignmentInBytes=8",

                                                   "-version");

        OutputAnalyzer output = new OutputAnalyzer(pb.start());

        checkSmallTables(output, (cardsShouldUseLargePages ? largePageSize : smallPageSize));

        checkBitmaps(output, (bitmapShouldUseLargePages ? largePageSize : smallPageSize));

        output.shouldHaveExitValue(0);

        // Test with large page disabled.

        pb = ProcessTools.createJavaProcessBuilder("-XX:+UseG1GC",

                                                   "-XX:G1HeapRegionSize=" + HEAP_REGION_SIZE,

                                                   "-Xmx" + heapsize,

                                                   "-Xlog:pagesize",

                                                   "-XX:-UseLargePages",

                                                   "-XX:+IgnoreUnrecognizedVMOptions",  // there is no ObjectAlignmentInBytes in 32 bit builds

                                                   "-XX:ObjectAlignmentInBytes=8",

                                                   "-version");

        output = new OutputAnalyzer(pb.start());

        checkSmallTables(output, smallPageSize);

        checkBitmaps(output, smallPageSize);

        output.shouldHaveExitValue(0);

    }

    private static long gcd(long x, long y) {

        while (x > 0) {

            long t = x;

            x = y % x;

            y = t;

        }

        return y;

    }

    private static long lcm(long x, long y) {

        return x * (y / gcd(x, y));

    }

    public static void main(String[] args) throws Exception {

        // Size that a single card covers.

        final int cardSize = 512;

        WhiteBox wb = WhiteBox.getWhiteBox();

        smallPageSize = wb.getVMPageSize();

        largePageSize = wb.getVMLargePageSize();

        allocGranularity = wb.getVMAllocationGranularity();

        final long heapAlignment = lcm(cardSize * smallPageSize, largePageSize);

        if (largePageSize == 0) {

            System.out.println("Skip tests because large page support does not seem to be available on this platform.");

            return;

        }

        if (largePageSize == smallPageSize) {

            System.out.println("Skip tests because large page support does not seem to be available on this platform." +

                               "Small and large page size are the same.");

            return;

        }

        // To get large pages for the card table etc. we need at least a 1G heap (with 4k page size).

        // 32 bit systems will have problems reserving such an amount of contiguous space, so skip the

        // test there.

        if (!Platform.is32bit()) {

            final long heapSizeForCardTableUsingLargePages = largePageSize * cardSize;

            final long heapSizeDiffForCardTable = Math.max(Math.max(allocGranularity * cardSize, HEAP_REGION_SIZE), largePageSize);

            Asserts.assertGT(heapSizeForCardTableUsingLargePages, heapSizeDiffForCardTable,

                             "To test we would require to use an invalid heap size");

            testVM("case1: card table and bitmap use large pages (barely)", heapSizeForCardTableUsingLargePages, true, true);

            testVM("case2: card table and bitmap use large pages (extra slack)", heapSizeForCardTableUsingLargePages + heapSizeDiffForCardTable, true, true);

            testVM("case3: only bitmap uses large pages (barely not)", heapSizeForCardTableUsingLargePages - heapSizeDiffForCardTable, false, true);

        }

        // Minimum heap requirement to get large pages for bitmaps is 128M heap. This seems okay to test

        // everywhere.

        final int bitmapTranslationFactor = 8 * 8; // ObjectAlignmentInBytes * BitsPerByte

        final long heapSizeForBitmapUsingLargePages = largePageSize * bitmapTranslationFactor;

        final long heapSizeDiffForBitmap = Math.max(Math.max(allocGranularity * bitmapTranslationFactor, HEAP_REGION_SIZE),

                                                    Math.max(largePageSize, heapAlignment));

        Asserts.assertGT(heapSizeForBitmapUsingLargePages, heapSizeDiffForBitmap,

                         "To test we would require to use an invalid heap size");

        testVM("case4: only bitmap uses large pages (barely)", heapSizeForBitmapUsingLargePages, false, true);

        testVM("case5: only bitmap uses large pages (extra slack)", heapSizeForBitmapUsingLargePages + heapSizeDiffForBitmap, false, true);

        testVM("case6: nothing uses large pages (barely not)", heapSizeForBitmapUsingLargePages - heapSizeDiffForBitmap, false, false);

    }

    public static long parseMemoryString(String value) {

        long multiplier = 1;

        if (value.endsWith("B")) {

            multiplier = 1;

        } else if (value.endsWith("K")) {

            multiplier = 1024;

        } else if (value.endsWith("M")) {

            multiplier = 1024 * 1024;

        } else if (value.endsWith("G")) {

            multiplier = 1024 * 1024 * 1024;

        } else {

            throw new IllegalArgumentException("Expected memory string '" + value + "'to end with either of: B, K, M, G");

        }

        long longValue = Long.parseUnsignedLong(value.substring(0, value.length() - 1));

        return longValue * multiplier;

    }

}