9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /** 25 * @test TestSmallHeap 26 * @bug 8067438 8152239 27 * @requires vm.gc=="null" 28 * @summary Verify that starting the VM with a small heap works 29 * @library /testlibrary /test/lib /test/lib/share/classes 30 * @modules java.base/jdk.internal.misc 31 * @modules java.management/sun.management 32 * @build TestSmallHeap 33 * @run main ClassFileInstaller sun.hotspot.WhiteBox 34 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI TestSmallHeap 35 */ 36 37 /* Note: It would be nice to verify the minimal supported heap size here, 38 * but we align the heap size based on the card table size. And the card table 39 * size is aligned based on the minimal pages size provided by the os. This 40 * means that on most platforms, where the minimal page size is 4k, we get a 41 * minimal heap size of 2m but on Solaris/Sparc we have a page size of 8k and 42 * get a minimal heap size of 4m. And on platforms where the page size is 64k 43 * we get a minimal heap size of 32m. We never use large pages for the card table. 44 * 45 * There is also no check in the VM for verifying that the maximum heap size 46 * is larger than the supported minimal heap size. 47 * 48 * To work around these behaviors this test uses -Xmx4m but then 49 * calculates what the expected heap size should be. The calculation is a 50 * simplified version of the code in the VM. We assume that the card table will 51 * use one page. Each byte in the card table corresponds to 512 bytes on the heap. 52 * So, the expected heap size is page_size * 512. | 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /** 25 * @test TestSmallHeap 26 * @bug 8067438 8152239 27 * @requires vm.gc=="null" 28 * @summary Verify that starting the VM with a small heap works 29 * @library /test/lib 30 * @modules java.base/jdk.internal.misc 31 * @modules java.management/sun.management 32 * @build sun.hotspot.WhiteBox 33 * @run main ClassFileInstaller sun.hotspot.WhiteBox 34 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI TestSmallHeap 35 */ 36 37 /* Note: It would be nice to verify the minimal supported heap size here, 38 * but we align the heap size based on the card table size. And the card table 39 * size is aligned based on the minimal pages size provided by the os. This 40 * means that on most platforms, where the minimal page size is 4k, we get a 41 * minimal heap size of 2m but on Solaris/Sparc we have a page size of 8k and 42 * get a minimal heap size of 4m. And on platforms where the page size is 64k 43 * we get a minimal heap size of 32m. We never use large pages for the card table. 44 * 45 * There is also no check in the VM for verifying that the maximum heap size 46 * is larger than the supported minimal heap size. 47 * 48 * To work around these behaviors this test uses -Xmx4m but then 49 * calculates what the expected heap size should be. The calculation is a 50 * simplified version of the code in the VM. We assume that the card table will 51 * use one page. Each byte in the card table corresponds to 512 bytes on the heap. 52 * So, the expected heap size is page_size * 512. |