container/libcontainer: Add limit parsing benchmark

Author: brancz

container/libcontainer/handler_test.go

@@ -296,3 +296,18 @@ func TestClearReferencedBytesWhenClearRefsMissing(t *testing.T) {
 	err := clearReferencedBytes(pids, 0, 1)
 	assert.Nil(t, err)
 }
+
+var ulimits []info.UlimitSpec
+
+func BenchmarkProcessLimitsFile(b *testing.B) {
+	content, err := os.ReadFile("testdata/limits")
+	assert.Nil(b, err)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		ulimits = processLimitsFile(string(content))
+	}
+
+	// Ensure the compiler doesn't optimize away the benchmark
+	_ = ulimits
+}

container/libcontainer/testdata/limits

@@ -0,0 +1,17 @@
+Limit                     Soft Limit           Hard Limit           Units     
+Max cpu time              unlimited            unlimited            seconds   
+Max file size             unlimited            unlimited            bytes     
+Max data size             unlimited            unlimited            bytes     
+Max stack size            8388608              unlimited            bytes     
+Max core file size        unlimited            unlimited            bytes     
+Max resident set          unlimited            unlimited            bytes     
+Max processes             119958               119958               processes 
+Max open files            1073741816           1073741816           files     
+Max locked memory         3932852224           3932852224           bytes     
+Max address space         unlimited            unlimited            bytes     
+Max file locks            unlimited            unlimited            locks     
+Max pending signals       119958               119958               signals   
+Max msgqueue size         819200               819200               bytes     
+Max nice priority         0                    0                    
+Max realtime priority     0                    0                    
+Max realtime timeout      unlimited            unlimited            us