Add tracing. (#943)

candle-examples/examples/yolo-v8/main.rs

@@ -7,7 +7,7 @@ extern crate accelerate_src;
 mod model;
 use model::{Multiples, YoloV8, YoloV8Pose};
 
-use candle::{DType, Device, IndexOp, Result, Tensor};
+use candle::{DType, IndexOp, Result, Tensor};
 use candle_nn::{Module, VarBuilder};
 use candle_transformers::object_detection::{non_maximum_suppression, Bbox, KeyPoint};
 use clap::{Parser, ValueEnum};
@@ -253,6 +253,14 @@ enum YoloTask {
 #[derive(Parser, Debug)]
 #[command(author, version, about, long_about = None)]
 pub struct Args {
+    /// Run on CPU rather than on GPU.
+    #[arg(long)]
+    cpu: bool,
+
+    /// Enable tracing (generates a trace-timestamp.json file).
+    #[arg(long)]
+    tracing: bool,
+
     /// Model weights, in safetensors format.
     #[arg(long)]
     model: Option<String>,
@@ -363,6 +371,7 @@ impl Task for YoloV8Pose {
 }
 
 pub fn run<T: Task>(args: Args) -> anyhow::Result<()> {
+    let device = candle_examples::device(args.cpu)?;
     // Create the model and load the weights from the file.
     let multiples = match args.which {
         Which::N => Multiples::n(),
@@ -374,7 +383,7 @@ pub fn run<T: Task>(args: Args) -> anyhow::Result<()> {
     let model = args.model()?;
     let weights = unsafe { candle::safetensors::MmapedFile::new(model)? };
     let weights = weights.deserialize()?;
-    let vb = VarBuilder::from_safetensors(vec![weights], DType::F32, &Device::Cpu);
+    let vb = VarBuilder::from_safetensors(vec![weights], DType::F32, &device);
     let model = T::load(vb, multiples)?;
     println!("model loaded");
     for image_name in args.images.iter() {
@@ -405,7 +414,7 @@ pub fn run<T: Task>(args: Args) -> anyhow::Result<()> {
             Tensor::from_vec(
                 data,
                 (img.height() as usize, img.width() as usize, 3),
-                &Device::Cpu,
+                &device,
             )?
             .permute((2, 0, 1))?
         };
@@ -430,7 +439,19 @@ pub fn run<T: Task>(args: Args) -> anyhow::Result<()> {
 }
 
 pub fn main() -> anyhow::Result<()> {
+    use tracing_chrome::ChromeLayerBuilder;
+    use tracing_subscriber::prelude::*;
+
     let args = Args::parse();
+
+    let _guard = if args.tracing {
+        let (chrome_layer, guard) = ChromeLayerBuilder::new().build();
+        tracing_subscriber::registry().with(chrome_layer).init();
+        Some(guard)
+    } else {
+        None
+    };
+
     match args.task {
         YoloTask::Detect => run::<YoloV8>(args)?,
         YoloTask::Pose => run::<YoloV8Pose>(args)?,