scx_utils: cleanup gpu topology part

code using more modern construct to replace simple match patterns
mostly, simplifying loops.

rust/scx_utils/src/gpu.rs

@@ -29,51 +29,48 @@ pub fn create_gpus() -> BTreeMap<usize, Vec<Gpu>> {
     let Ok(nvml) = Nvml::init_with_flags(InitFlags::NO_GPUS) else {
         return BTreeMap::new();
     };
-    match nvml.device_count() {
-        Ok(nvidia_gpu_count) => {
-            for i in 0..nvidia_gpu_count {
-                let Ok(nvidia_gpu) = nvml.device_by_index(i) else {
-                    continue;
-                };
-                let graphics_boost_clock = nvidia_gpu
-                    .max_customer_boost_clock(Clock::Graphics)
-                    .unwrap_or(0);
-                let sm_boost_clock = nvidia_gpu.max_customer_boost_clock(Clock::SM).unwrap_or(0);
-                let Ok(memory_info) = nvidia_gpu.memory_info() else {
-                    continue;
-                };
-                let Ok(pci_info) = nvidia_gpu.pci_info() else {
-                    continue;
-                };
-                let Ok(index) = nvidia_gpu.index() else {
-                    continue;
-                };
+    if let Ok(nvidia_gpu_count) = nvml.device_count() {
+        for i in 0..nvidia_gpu_count {
+            let Ok(nvidia_gpu) = nvml.device_by_index(i) else {
+                continue;
+            };
+            let graphics_boost_clock = nvidia_gpu
+                .max_customer_boost_clock(Clock::Graphics)
+                .unwrap_or(0);
+            let sm_boost_clock = nvidia_gpu.max_customer_boost_clock(Clock::SM).unwrap_or(0);
+            let Ok(memory_info) = nvidia_gpu.memory_info() else {
+                continue;
+            };
+            let Ok(pci_info) = nvidia_gpu.pci_info() else {
+                continue;
+            };
+            let Ok(index) = nvidia_gpu.index() else {
+                continue;
+            };
 
-                // The NVML library doesn't return a PCIe bus ID compatible with sysfs. It includes
-                // uppercase bus ID values and an extra four leading 0s.
-                let bus_id = pci_info.bus_id.to_lowercase();
-                let fixed_bus_id = bus_id.strip_prefix("0000").unwrap_or("");
-                let numa_path = format!("/sys/bus/pci/devices/{}/numa_node", fixed_bus_id);
-                let numa_node = read_file_usize(&Path::new(&numa_path)).unwrap_or(0);
+            // The NVML library doesn't return a PCIe bus ID compatible with sysfs. It includes
+            // uppercase bus ID values and an extra four leading 0s.
+            let bus_id = pci_info.bus_id.to_lowercase();
+            let fixed_bus_id = bus_id.strip_prefix("0000").unwrap_or("");
+            let numa_path = format!("/sys/bus/pci/devices/{}/numa_node", fixed_bus_id);
+            let numa_node = read_file_usize(&Path::new(&numa_path)).unwrap_or(0);
 
-                let gpu = Gpu {
-                    index: GpuIndex::Nvidia { nvml_id: index },
-                    node_id: numa_node as usize,
-                    max_graphics_clock: graphics_boost_clock as usize,
-                    max_sm_clock: sm_boost_clock as usize,
-                    memory: memory_info.total,
-                };
-                if !gpus.contains_key(&numa_node) {
-                    gpus.insert(numa_node, vec![gpu]);
-                    continue;
-                }
-                if let Some(gpus) = gpus.get_mut(&numa_node) {
-                    gpus.push(gpu);
-                }
+            let gpu = Gpu {
+                index: GpuIndex::Nvidia { nvml_id: index },
+                node_id: numa_node as usize,
+                max_graphics_clock: graphics_boost_clock as usize,
+                max_sm_clock: sm_boost_clock as usize,
+                memory: memory_info.total,
+            };
+            if !gpus.contains_key(&numa_node) {
+                gpus.insert(numa_node, vec![gpu]);
+                continue;
+            }
+            if let Some(gpus) = gpus.get_mut(&numa_node) {
+                gpus.push(gpu);
             }
         }
-        _ => {}
-    };
+    }
 
     gpus
 }

rust/scx_utils/src/topology.rs

@@ -270,9 +270,9 @@ impl Topology {
     #[cfg(feature = "gpu-topology")]
     pub fn gpus(&self) -> BTreeMap<GpuIndex, &Gpu> {
         let mut gpus = BTreeMap::new();
-        for (_, node) in &self.nodes {
+        for node in self.nodes.values() {
             for (idx, gpu) in &node.gpus {
-                gpus.insert(idx.clone(), gpu);
+                gpus.insert(*idx, gpu);
             }
         }
         gpus
@@ -582,14 +582,11 @@ fn create_default_node(
     #[cfg(feature = "gpu-topology")]
     {
         let system_gpus = create_gpus();
-        match system_gpus.get(&0) {
-            Some(gpus) => {
-                for gpu in gpus {
-                    node.gpus.insert(gpu.index, gpu.clone());
-                }
+        if let Some(gpus) = system_gpus.get(&0) {
+            for gpu in gpus {
+                node.gpus.insert(gpu.index, gpu.clone());
             }
-            _ => {}
-        };
+        }
     }
 
     if !Path::new("/sys/devices/system/cpu").exists() {
@@ -647,14 +644,11 @@ fn create_numa_nodes(
 
         #[cfg(feature = "gpu-topology")]
         {
-            match system_gpus.get(&node_id) {
-                Some(gpus) => {
-                    for gpu in gpus {
-                        node.gpus.insert(gpu.index, gpu.clone());
-                    }
+            if let Some(gpus) = system_gpus.get(&node_id) {
+                for gpu in gpus {
+                    node.gpus.insert(gpu.index, gpu.clone());
                 }
-                _ => {}
-            };
+            }
         }
 
         let cpu_pattern = numa_path.join("cpu[0-9]*");