test: add unit test for per block device metrics

Add unit test for block inc metrics and shared metrics. Signed-off-by: Sudan Landge <sudanl@amazon.com>
firecracker-microvm · Oct 27, 2023 · f2209b5 · f2209b5
1 parent 333f88e
commit f2209b5
Showing 1 changed file with 178 additions and 0 deletions.
diff --git a/src/vmm/src/devices/virtio/block/block_metrics.rs b/src/vmm/src/devices/virtio/block/block_metrics.rs
@@ -221,3 +221,181 @@ impl BlockDeviceMetrics {
             .add(other.io_engine_throttled_events.fetch_diff());
     }
 }
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+
+    #[test]
+    fn test_max_block_dev_metrics() {
+        // Note: this test has nothing to do with
+        // block structure or IRQs, this is just to allocate
+        // metrics for max number of devices that system can have.
+        // we have 5-23 irq for block devices on x86_64 so max
+        // 19 block devices and, although on aarch64 we have more
+        // devices but we stick to 19 to keep test common.
+        const MAX_BLOCK_DEVICES: usize = 19;
+
+        assert!(BLOCK_METRICS.read().is_ok());
+        assert!(BLOCK_METRICS.write().is_ok());
+
+        for i in 0..MAX_BLOCK_DEVICES {
+            let devn: String = format!("drv{}", i);
+            BlockMetricsPerDevice::alloc(devn.clone());
+            BLOCK_METRICS
+                .read()
+                .unwrap()
+                .metrics
+                .get(&devn)
+                .unwrap()
+                .activate_fails
+                .inc();
+            BLOCK_METRICS
+                .read()
+                .unwrap()
+                .metrics
+                .get(&devn)
+                .unwrap()
+                .read_bytes
+                .add(10);
+            BLOCK_METRICS
+                .read()
+                .unwrap()
+                .metrics
+                .get(&devn)
+                .unwrap()
+                .write_bytes
+                .add(5);
+        }
+
+        for i in 0..MAX_BLOCK_DEVICES {
+            let devn: String = format!("drv{}", i);
+            assert!(
+                BLOCK_METRICS
+                    .read()
+                    .unwrap()
+                    .metrics
+                    .get(&devn)
+                    .unwrap()
+                    .activate_fails
+                    .count()
+                    >= 1
+            );
+            assert!(
+                BLOCK_METRICS
+                    .read()
+                    .unwrap()
+                    .metrics
+                    .get(&devn)
+                    .unwrap()
+                    .read_bytes
+                    .count()
+                    >= 10
+            );
+            assert_eq!(
+                BLOCK_METRICS
+                    .read()
+                    .unwrap()
+                    .metrics
+                    .get(&devn)
+                    .unwrap()
+                    .write_bytes
+                    .count(),
+                5
+            );
+        }
+    }
+
+    #[test]
+    fn test_signle_block_dev_metrics() {
+        // Use drv0 so that we can check thread safety with the
+        // `test_max_block_dev_metrics` which also uses the same name.
+        let devn = "drv0";
+
+        assert!(BLOCK_METRICS.read().is_ok());
+        assert!(BLOCK_METRICS.write().is_ok());
+
+        BlockMetricsPerDevice::alloc(String::from(devn));
+        assert!(BLOCK_METRICS.read().is_ok());
+        assert!(BLOCK_METRICS.read().unwrap().metrics.get(devn).is_some());
+
+        BLOCK_METRICS
+            .read()
+            .unwrap()
+            .metrics
+            .get(devn)
+            .unwrap()
+            .activate_fails
+            .inc();
+        assert!(
+            BLOCK_METRICS
+                .read()
+                .unwrap()
+                .metrics
+                .get(devn)
+                .unwrap()
+                .activate_fails
+                .count()
+                > 0,
+            "{}",
+            BLOCK_METRICS
+                .read()
+                .unwrap()
+                .metrics
+                .get(devn)
+                .unwrap()
+                .activate_fails
+                .count()
+        );
+        // we expect only 2 tests (this and test_max_block_dev_metrics)
+        // to update activate_fails count for drv0.
+        assert!(
+            BLOCK_METRICS
+                .read()
+                .unwrap()
+                .metrics
+                .get(devn)
+                .unwrap()
+                .activate_fails
+                .count()
+                <= 2,
+            "{}",
+            BLOCK_METRICS
+                .read()
+                .unwrap()
+                .metrics
+                .get(devn)
+                .unwrap()
+                .activate_fails
+                .count()
+        );
+
+        BLOCK_METRICS
+            .read()
+            .unwrap()
+            .metrics
+            .get(devn)
+            .unwrap()
+            .activate_fails
+            .inc();
+        BLOCK_METRICS
+            .read()
+            .unwrap()
+            .metrics
+            .get(devn)
+            .unwrap()
+            .read_bytes
+            .add(5);
+        assert!(
+            BLOCK_METRICS
+                .read()
+                .unwrap()
+                .metrics
+                .get(devn)
+                .unwrap()
+                .read_bytes
+                .count()
+                >= 5
+        );
+    }
+}