8299858: [Metrics] Swap memory limit reported incorrectly when too large

Reviewed-by: stuefe

src/java.base/linux/classes/jdk/internal/platform/CgroupMetrics.java

@@ -122,9 +122,11 @@ public class CgroupMetrics implements Metrics {
     @Override
     public long getMemoryLimit() {
         long subsMem = subsystem.getMemoryLimit();
+        long systemTotal = getTotalMemorySize0();
+        assert(systemTotal > 0);
         // Catch the cgroup memory limit exceeding host physical memory.
         // Treat this as unlimited.
-        if (subsMem >= getTotalMemorySize0()) {
+        if (subsMem >= systemTotal) {
             return CgroupSubsystem.LONG_RETVAL_UNLIMITED;
         }
         return subsMem;
@@ -142,7 +144,15 @@ public class CgroupMetrics implements Metrics {
 
     @Override
     public long getMemoryAndSwapLimit() {
-        return subsystem.getMemoryAndSwapLimit();
+        long totalSystemMemSwap = getTotalMemorySize0() + getTotalSwapSize0();
+        assert(totalSystemMemSwap > 0);
+        // Catch the cgroup memory and swap limit exceeding host physical swap
+        // and memory. Treat this case as unlimited.
+        long subsSwapMem = subsystem.getMemoryAndSwapLimit();
+        if (subsSwapMem >= totalSystemMemSwap) {
+            return CgroupSubsystem.LONG_RETVAL_UNLIMITED;
+        }
+        return subsSwapMem;
     }
 
     @Override
@@ -185,5 +195,6 @@ public class CgroupMetrics implements Metrics {
 
     private static native boolean isUseContainerSupport();
     private static native long getTotalMemorySize0();
+    private static native long getTotalSwapSize0();
 
 }

src/java.base/linux/native/libjava/CgroupMetrics.c

@@ -23,6 +23,7 @@
  * questions.
  */
 #include <unistd.h>
+#include <sys/sysinfo.h>
 
 #include "jni.h"
 #include "jvm.h"
@@ -43,3 +44,15 @@ Java_jdk_internal_platform_CgroupMetrics_getTotalMemorySize0
     jlong page_size = sysconf(_SC_PAGESIZE);
     return pages * page_size;
 }
+
+JNIEXPORT jlong JNICALL
+Java_jdk_internal_platform_CgroupMetrics_getTotalSwapSize0
+  (JNIEnv *env, jclass ignored)
+{
+    struct sysinfo si;
+    int retval = sysinfo(&si);
+    if (retval < 0) {
+         return 0; // syinfo failed, treat as no swap
+    }
+    return (jlong)si.totalswap;
+}

test/hotspot/jtreg/containers/docker/TestMemoryAwareness.java

@@ -37,6 +37,7 @@
  * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar whitebox.jar jdk.test.whitebox.WhiteBox
  * @run main/othervm -Xbootclasspath/a:whitebox.jar -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI TestMemoryAwareness
  */
+import java.util.function.Consumer;
 import jdk.test.lib.containers.docker.Common;
 import jdk.test.lib.containers.docker.DockerRunOptions;
 import jdk.test.lib.containers.docker.DockerTestUtils;
@@ -96,7 +97,9 @@ public class TestMemoryAwareness {
                 true /* additional cgroup fs mounts */
             );
             testOSMXBeanIgnoresMemLimitExceedingPhysicalMemory();
+            testOSMXBeanIgnoresSwapLimitExceedingPhysical();
             testMetricsExceedingPhysicalMemory();
+            testMetricsSwapExceedingPhysical();
             testContainerMemExceedsPhysical();
         } finally {
             if (!DockerTestUtils.RETAIN_IMAGE_AFTER_TEST) {
@@ -183,6 +186,13 @@ public class TestMemoryAwareness {
 
     private static void testOperatingSystemMXBeanAwareness(String memoryAllocation, String expectedMemory,
             String swapAllocation, String expectedSwap, boolean addCgroupMounts) throws Exception {
+        Consumer<OutputAnalyzer> noOp = o -> {};
+        testOperatingSystemMXBeanAwareness(memoryAllocation, expectedMemory, swapAllocation, expectedSwap, false, noOp);
+    }
+
+    private static void testOperatingSystemMXBeanAwareness(String memoryAllocation, String expectedMemory,
+            String swapAllocation, String expectedSwap, boolean addCgroupMounts,
+            Consumer<OutputAnalyzer> additionalMatch) throws Exception {
 
         Common.logNewTestCase("Check OperatingSystemMXBean");
 
@@ -191,6 +201,7 @@ public class TestMemoryAwareness {
                 "--memory", memoryAllocation,
                 "--memory-swap", swapAllocation
             )
+            .addJavaOpts("-esa")
             // CheckOperatingSystemMXBean uses Metrics (jdk.internal.platform) for
             // diagnostics
             .addJavaOpts("--add-exports")
@@ -228,9 +239,9 @@ public class TestMemoryAwareness {
         } catch(RuntimeException ex) {
             out.shouldMatch("OperatingSystemMXBean\\.getFreeSwapSpaceSize: 0");
         }
+        additionalMatch.accept(out);
     }
 
-
     // JDK-8292541: Ensure OperatingSystemMXBean ignores container memory limits above the host's physical memory.
     private static void testOSMXBeanIgnoresMemLimitExceedingPhysicalMemory()
             throws Exception {
@@ -239,6 +250,35 @@ public class TestMemoryAwareness {
         testOperatingSystemMXBeanAwareness(badMem, hostMaxMem, badMem, hostMaxMem);
     }
 
+    private static void testOSMXBeanIgnoresSwapLimitExceedingPhysical()
+            throws Exception {
+        long totalSwap = wb.hostPhysicalSwap() + wb.hostPhysicalMemory();
+        String expectedSwap = Long.valueOf(totalSwap).toString();
+        String hostMaxMem = getHostMaxMemory();
+        String badMem = hostMaxMem + "0";
+        final String badSwap = expectedSwap + "0";
+        testOperatingSystemMXBeanAwareness(badMem, hostMaxMem, badSwap, expectedSwap, false, o -> {
+            o.shouldNotContain("Metrics.getMemoryAndSwapLimit() == " + badSwap);
+        });
+    }
+
+    private static void testMetricsSwapExceedingPhysical()
+            throws Exception {
+        Common.logNewTestCase("Metrics ignore container swap memory limit exceeding physical");
+        long totalSwap = wb.hostPhysicalSwap() + wb.hostPhysicalMemory();
+        String expectedSwap = Long.valueOf(totalSwap).toString();
+        final String badSwap = expectedSwap + "0";
+        String badMem = getHostMaxMemory() + "0";
+        DockerRunOptions opts = Common.newOpts(imageName)
+            .addJavaOpts("-XshowSettings:system")
+            .addDockerOpts("--memory", badMem)
+            .addDockerOpts("--memory-swap", badSwap);
+
+        OutputAnalyzer out = DockerTestUtils.dockerRunJava(opts);
+        out.shouldContain("Memory Limit: Unlimited");
+        out.shouldContain("Memory & Swap Limit: Unlimited");
+    }
+
     // JDK-8292541: Ensure Metrics ignores container memory limits above the host's physical memory.
     private static void testMetricsExceedingPhysicalMemory()
             throws Exception {