Update nvmlDeviceGetMemoryInfo to version 2 to be consistent with nvidia-smi (#58)

Update API call used in Device::memory_info to use nvmlDeviceGetMemoryInfo_v2.

Fixes #57.

Author: marcelroed

nvml-wrapper/src/device.rs

@@ -2128,10 +2128,13 @@ impl<'nvml> Device<'nvml> {
     // Tested
     #[doc(alias = "nvmlDeviceGetMemoryInfo")]
     pub fn memory_info(&self) -> Result<MemoryInfo, NvmlError> {
-        let sym = nvml_sym(self.nvml.lib.nvmlDeviceGetMemoryInfo.as_ref())?;
+        let sym = nvml_sym(self.nvml.lib.nvmlDeviceGetMemoryInfo_v2.as_ref())?;
 
         unsafe {
-            let mut info: nvmlMemory_t = mem::zeroed();
+            let mut info: nvmlMemory_v2_t = mem::zeroed();
+
+            // Implements NVML_STRUCT_VERSION(Memory, 2), as detailed in nvml.h (https://github.com/NVIDIA/nvidia-settings/issues/78)
+            info.version = (std::mem::size_of::<nvmlMemory_v2_t>() | (2_usize << 24_usize)) as u32;
             nvml_try(sym(self.device, &mut info))?;
 
             Ok(info.into())

nvml-wrapper/src/struct_wrappers/device.rs

@@ -290,21 +290,30 @@ impl From<nvmlEccErrorCounts_t> for EccErrorCounts {
 pub struct MemoryInfo {
     /// Unallocated FB memory.
     pub free: u64,
+
+    /// Reserved FB memory.
+    pub reserved: u64,
+
     /// Total installed FB memory.
     pub total: u64,
     /// Allocated FB memory.
     ///
     /// Note that the driver/GPU always sets aside a small amount of memory for
     /// bookkeeping.
     pub used: u64,
+
+    /// Struct version, must be set according to API specification before calling the API.
+    pub version: u32,
 }
 
-impl From<nvmlMemory_t> for MemoryInfo {
-    fn from(struct_: nvmlMemory_t) -> Self {
+impl From<nvmlMemory_v2_t> for MemoryInfo {
+    fn from(struct_: nvmlMemory_v2_t) -> Self {
         Self {
             free: struct_.free,
+            reserved: struct_.reserved,
             total: struct_.total,
             used: struct_.used,
+            version: struct_.version,
         }
     }
 }