Fix resource detection for unset CPU and memory limits in cgroup v2 (#…

…5267) * Fix resource detection for unset CPU and memory limits in cgroup v2 Address the issue where `/sys/fs/cgroup/cpu.max` and `/sys/fs/cgroup/memory.max` report "max", indicating unset limits in cgroup v2. Now, system resources (CPU cores and memory) are fetched directly from `/proc/stat` and `/proc/meminfo` limits are not set.. * Small improvements * Build fixes * Fixes to LinuxUtilizationParserCgroupV2.cs --------- Co-authored-by: Martin Obrátil <[email protected]> Co-authored-by: Martin Obrátil <[email protected]>
dotnet · Jul 23, 2024 · 6a3cb23 · 6a3cb23
1 parent 0d82461
commit 6a3cb23
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diff --git a/...crosoft.Extensions.Diagnostics.ResourceMonitoring/Linux/LinuxUtilizationParserCgroupV2.cs b/...crosoft.Extensions.Diagnostics.ResourceMonitoring/Linux/LinuxUtilizationParserCgroupV2.cs
@@ -217,6 +217,12 @@ public ulong GetAvailableMemoryInBytes()
             _fileSystem.ReadAll(_memoryLimitInBytes, bufferWriter.Buffer);
 
             ReadOnlySpan<char> memoryBuffer = bufferWriter.Buffer.WrittenSpan;
+
+            if (memoryBuffer.Equals("max\n", StringComparison.InvariantCulture))
+            {
+                return GetHostAvailableMemory();
+            }
+
             _ = GetNextNumber(memoryBuffer, out maybeMemory);
 
             if (maybeMemory == -1)
@@ -497,7 +503,13 @@ private static bool TryGetCpuUnitsFromCgroups(IFileSystem fileSystem, out float
             return false;
         }
 
-        int nextQuota = GetNextNumber(quotaBuffer, out long quota);
+        if (quotaBuffer.StartsWith("max", StringComparison.InvariantCulture))
+        {
+            cpuUnits = 0;
+            return false;
+        }
+
+        _ = GetNextNumber(quotaBuffer, out long quota);
 
         if (quota == -1)
         {

diff --git a/...ensions.Diagnostics.ResourceMonitoring.Tests/Linux/LinuxUtilizationParserCgroupV2Tests.cs b/...ensions.Diagnostics.ResourceMonitoring.Tests/Linux/LinuxUtilizationParserCgroupV2Tests.cs
@@ -118,6 +118,23 @@ public void When_Calling_GetMemoryUsageInBytes_Parser_Throws_When_UsageInBytes_D
         Assert.Contains("/sys/fs/cgroup/memory.current", r.Message);
     }
 
+    [ConditionalTheory]
+    [InlineData("max\n", 134_796_910_592ul)]
+    [InlineData("1000000\n", 1_000_000ul)]
+    public void When_Calling_GetAvailableMemoryInBytes_Parser_Returns_Available_Memory(string content, ulong expectedResult)
+    {
+        var f = new HardcodedValueFileSystem(new Dictionary<FileInfo, string>
+        {
+            { new FileInfo("/sys/fs/cgroup/memory.max"), content },
+            { new FileInfo("/proc/meminfo"), "MemTotal:       131637608 kB" }
+        });
+
+        var p = new LinuxUtilizationParserCgroupV2(f, new FakeUserHz(100));
+        var result = p.GetAvailableMemoryInBytes();
+
+        Assert.Equal(expectedResult, result);
+    }
+
     [ConditionalTheory]
     [InlineData("Suspicious12312312")]
     [InlineData("string@")]
@@ -257,6 +274,21 @@ public void When_No_Cgroup_Cpu_Limits_Are_Not_Set_We_Get_Available_Cpus_From_Cpu
         Assert.Equal(result, cpus);
     }
 
+    [ConditionalFact]
+    public void When_Cpu_Max_Is_Set_To_Max_We_Get_Available_Cpus_From_CpuSetCpus()
+    {
+        var f = new HardcodedValueFileSystem(new Dictionary<FileInfo, string>
+        {
+            { new FileInfo("/sys/fs/cgroup/cpuset.cpus.effective"), "0,1,2" },
+            { new FileInfo("/sys/fs/cgroup/cpu.max"), "max 100000" },
+        });
+
+        var p = new LinuxUtilizationParserCgroupV2(f, new FakeUserHz(100));
+        var cpus = p.GetCgroupLimitedCpus();
+
+        Assert.Equal(3, cpus);
+    }
+
     [ConditionalTheory]
     [InlineData("-11")]
     [InlineData("0-")]