Merge pull request #263 from huggingface/book_3

Book 3 (advanced loading + hub)

.github/workflows/book-cd.yml

@@ -1,7 +1,5 @@
 name: Deploy Rust book
 on:
-  # TODO put this back only when merging after this PR lands.
-  pull_request:
   push:
     branches:
       - main

candle-book/src/SUMMARY.md

@@ -12,16 +12,16 @@
 
 - [Running a model](inference/README.md)
     - [Using the hub](inference/hub.md)
-    - [Serialization](inference/serialization.md)
-    - [Advanced Cuda usage](inference/cuda/README.md)
-        - [Writing a custom kernel](inference/cuda/writing.md)
-        - [Porting a custom kernel](inference/cuda/porting.md)
-- [Error management](error_manage.md)
-- [Creating apps](apps/README.md)
-    - [Creating a WASM app](apps/wasm.md)
-    - [Creating a REST api webserver](apps/rest.md)
-    - [Creating a desktop Tauri app](apps/dekstop.md)
-- [Training](training/README.md)
-    - [MNIST](training/mnist.md)
-    - [Fine-tuning](training/finetuning.md)
-- [Using MKL](advanced/mkl.md)
+- [Error management]()
+- [Advanced Cuda usage]()
+    - [Writing a custom kernel]()
+    - [Porting a custom kernel]()
+- [Using MKL]()
+- [Creating apps]()
+    - [Creating a WASM app]()
+    - [Creating a REST api webserver]()
+    - [Creating a desktop Tauri app]()
+- [Training]()
+    - [MNIST]()
+    - [Fine-tuning]()
+    - [Serialization]()

candle-book/src/cuda/README.md

@@ -0,0 +1 @@
+# Advanced Cuda usage

candle-book/src/cuda/porting.md

@@ -0,0 +1 @@
+# Porting a custom kernel

candle-book/src/cuda/writing.md

@@ -0,0 +1 @@
+# Writing a custom kernel

candle-book/src/error_manage.md

@@ -1 +1,51 @@
 # Error management
+
+You might have seen in the code base a lot of `.unwrap()` or `?`.
+If you're unfamiliar with Rust check out the [Rust book](https://doc.rust-lang.org/book/ch09-02-recoverable-errors-with-result.html)
+for more information.
+
+What's important to know though, is that if you want to know *where* a particular operation failed
+You can simply use `RUST_BACKTRACE=1` to get the location of where the model actually failed.
+
+Let's see on failing code:
+
+```rust,ignore
+let x = Tensor::zeros((1, 784), DType::F32, &device)?;
+let y = Tensor::zeros((1, 784), DType::F32, &device)?;
+let z = x.matmul(&y)?;
+```
+
+Will print at runtime:
+
+```bash
+Error: ShapeMismatchBinaryOp { lhs: [1, 784], rhs: [1, 784], op: "matmul" }
+``` 
+
+
+After adding `RUST_BACKTRACE=1`:
+
+
+```bash
+Error: WithBacktrace { inner: ShapeMismatchBinaryOp { lhs: [1, 784], rhs: [1, 784], op: "matmul" }, backtrace: Backtrace [{ fn: "candle::error::Error::bt", file: "/home/nicolas/.cargo/git/checkouts/candle-5bb8ef7e0626d693/f291065/candle-core/src/error.rs", line: 200 }, { fn: "candle::tensor::Tensor::matmul", file: "/home/nicolas/.cargo/git/checkouts/candle-5bb8ef7e0626d693/f291065/candle-core/src/tensor.rs", line: 816 }, { fn: "myapp::main", file: "./src/main.rs", line: 29 }, { fn: "core::ops::function::FnOnce::call_once", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/core/src/ops/function.rs", line: 250 }, { fn: "std::sys_common::backtrace::__rust_begin_short_backtrace", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/sys_common/backtrace.rs", line: 135 }, { fn: "std::rt::lang_start::{{closure}}", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/rt.rs", line: 166 }, { fn: "core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/core/src/ops/function.rs", line: 284 }, { fn: "std::panicking::try::do_call", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/panicking.rs", line: 500 }, { fn: "std::panicking::try", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/panicking.rs", line: 464 }, { fn: "std::panic::catch_unwind", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/panic.rs", line: 142 }, { fn: "std::rt::lang_start_internal::{{closure}}", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/rt.rs", line: 148 }, { fn: "std::panicking::try::do_call", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/panicking.rs", line: 500 }, { fn: "std::panicking::try", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/panicking.rs", line: 464 }, { fn: "std::panic::catch_unwind", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/panic.rs", line: 142 }, { fn: "std::rt::lang_start_internal", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/rt.rs", line: 148 }, { fn: "std::rt::lang_start", file: "/rustc/8ede3aae28fe6e4d52b38157d7bfe0d3bceef225/library/std/src/rt.rs", line: 165 }, { fn: "main" }, { fn: "__libc_start_main" }, { fn: "_start" }] }
+```
+
+Not super pretty at the moment, but we can see error occured on `{ fn: "myapp::main", file: "./src/main.rs", line: 29 }`
+
+
+Another thing to note, is that since Rust is compiled it is not necessarily as easy to recover proper stacktraces
+especially in release builds. We're using [`anyhow`](https://docs.rs/anyhow/latest/anyhow/) for that.
+The library is still young, please [report](https://github.com/LaurentMazare/candle/issues) any issues detecting where an error is coming from.
+
+## Cuda error management
+
+When running a model on Cuda, you might get a stacktrace not really representing the error.
+The reason is that CUDA is async by nature, and therefore the error might be caught while you were sending totally different kernels.
+
+One way to avoid this is to use `CUDA_LAUNCH_BLOCKING=1` as an environment variable. This will force every kernel to be launched sequentially.
+You might still however see the error happening on other kernels as the faulty kernel might exit without an error but spoiling some pointer for which the error will happen when dropping the `CudaSlice` only.
+
+
+If this occurs, you can use [`compute-sanitizer`](https://docs.nvidia.com/compute-sanitizer/ComputeSanitizer/index.html)
+This tool is like `valgrind` but for cuda. It will help locate the errors in the kernels.
+
+

candle-book/src/inference/README.md

@@ -1 +1,7 @@
 # Running a model
+
+
+In order to run an existing model, you will need to download and use existing weights.
+Most models are already available on https://huggingface.co/ in [`safetensors`](https://github.com/huggingface/safetensors) format.
+
+Let's get started by running an old model : `bert-base-uncased`.

candle-book/src/inference/hub.md

@@ -1 +1,104 @@
 # Using the hub
+
+Install the [`hf-hub`](https://github.com/huggingface/hf-hub) crate:
+
+```bash
+cargo add hf-hub
+```
+
+Then let's start by downloading the [model file](https://huggingface.co/bert-base-uncased/tree/main).
+
+
+```rust
+# extern crate candle_core;
+# extern crate hf_hub;
+use hf_hub::api::sync::Api;
+use candle_core::Device;
+
+let api = Api::new().unwrap();
+let repo = api.model("bert-base-uncased".to_string());
+
+let weights = repo.get("model.safetensors").unwrap();
+
+let weights = candle_core::safetensors::load(weights, &Device::Cpu);
+```
+
+We now have access to all the [tensors](https://huggingface.co/bert-base-uncased?show_tensors=true) within the file.
+
+You can check all the names of the tensors [here](https://huggingface.co/bert-base-uncased?show_tensors=true)
+
+
+## Using async 
+
+`hf-hub` comes with an async API.
+
+```bash
+cargo add hf-hub --features tokio
+```
+
+```rust,ignore
+# This is tested directly in examples crate because it needs external dependencies unfortunately:
+# See [this](https://github.com/rust-lang/mdBook/issues/706)
+{{#include ../../../candle-examples/src/lib.rs:book_hub_1}}
+```
+
+
+## Using in a real model.
+
+Now that we have our weights, we can use them in our bert architecture:
+
+```rust
+# extern crate candle_core;
+# extern crate candle_nn;
+# extern crate hf_hub;
+# use hf_hub::api::sync::Api;
+# 
+# let api = Api::new().unwrap();
+# let repo = api.model("bert-base-uncased".to_string());
+# 
+# let weights = repo.get("model.safetensors").unwrap();
+use candle_core::{Device, Tensor, DType};
+use candle_nn::Linear;
+
+let weights = candle_core::safetensors::load(weights, &Device::Cpu).unwrap();
+
+let weight = weights.get("bert.encoder.layer.0.attention.self.query.weight").unwrap();
+let bias = weights.get("bert.encoder.layer.0.attention.self.query.bias").unwrap();
+
+let linear = Linear::new(weight.clone(), Some(bias.clone()));
+
+let input_ids = Tensor::zeros((3, 768), DType::F32, &Device::Cpu).unwrap();
+let output = linear.forward(&input_ids).unwrap();
+```
+
+For a full reference, you can check out the full [bert](https://github.com/LaurentMazare/candle/tree/main/candle-examples/examples/bert) example.
+
+## Memory mapping
+
+For more efficient loading, instead of reading the file, you could use [`memmap2`](https://docs.rs/memmap2/latest/memmap2/)
+
+**Note**: Be careful about memory mapping it seems to cause issues on [Windows, WSL](https://github.com/AUTOMATIC1111/stable-diffusion-webui/issues/5893)
+and will definitely be slower on network mounted disk, because it will issue more read calls.
+
+```rust,ignore
+{{#include ../../../candle-examples/src/lib.rs:book_hub_2}}
+```
+
+**Note**: This operation is **unsafe**. [See the safety notice](https://docs.rs/memmap2/latest/memmap2/struct.Mmap.html#safety).
+In practice model files should never be modified, and the mmaps should be mostly READONLY anyway, so the caveat most likely does not apply, but always keep it in mind.
+
+
+## Tensor Parallel Sharding
+
+When using multiple GPUs to use in Tensor Parallel in order to get good latency, you can load only the part of the Tensor you need.
+
+For that you need to use [`safetensors`](https://crates.io/crates/safetensors) directly.
+
+```bash
+cargo add safetensors
+```
+
+
+```rust,ignore
+{{#include ../../../candle-examples/src/lib.rs:book_hub_3}}
+```

candle-core/src/safetensors.rs

@@ -242,7 +242,11 @@ fn convert_back(tensor: &Tensor) -> Result<Vec<u8>> {
 
 pub fn load<P: AsRef<Path>>(filename: P, device: &Device) -> Result<HashMap<String, Tensor>> {
     let data = std::fs::read(filename.as_ref())?;
-    let st = safetensors::SafeTensors::deserialize(&data)?;
+    load_buffer(&data[..], device)
+}
+
+pub fn load_buffer(data: &[u8], device: &Device) -> Result<HashMap<String, Tensor>> {
+    let st = safetensors::SafeTensors::deserialize(data)?;
     st.tensors()
         .into_iter()
         .map(|(name, view)| Ok((name, view.load(device)?)))

candle-examples/Cargo.toml

@@ -28,8 +28,8 @@ image = { workspace = true, optional = true }
 [dev-dependencies]
 anyhow = { workspace = true }
 byteorder = { workspace = true }
+hf-hub = { workspace = true, features=["tokio"]}
 clap = { workspace = true }
-hf-hub = { workspace = true }
 memmap2 = { workspace = true }
 rand = { workspace = true }
 tokenizers = { workspace = true, features = ["onig"] }
@@ -37,6 +37,8 @@ tracing = { workspace = true }
 tracing-chrome = { workspace = true }
 tracing-subscriber = { workspace = true }
 wav = { workspace = true }
+# Necessary to disambiguate with tokio in wasm examples which are 1.28.1
+tokio = "1.29.1"
 
 [build-dependencies]
 anyhow = { workspace = true }

candle-examples/src/lib.rs

@@ -11,3 +11,102 @@ pub fn device(cpu: bool) -> Result<Device> {
         Ok(device)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    // NOTE: Waiting on https://github.com/rust-lang/mdBook/pull/1856
+    #[rustfmt::skip]
+    #[tokio::test]
+    async fn book_hub_1() {
+// ANCHOR: book_hub_1
+use candle::Device;
+use hf_hub::api::tokio::Api;
+
+let api = Api::new().unwrap();
+let repo = api.model("bert-base-uncased".to_string());
+
+let weights_filename = repo.get("model.safetensors").await.unwrap();
+
+let weights = candle::safetensors::load(weights_filename, &Device::Cpu).unwrap();
+// ANCHOR_END: book_hub_1
+        assert_eq!(weights.len(), 206);
+    }
+
+    #[rustfmt::skip]
+    #[test]
+    fn book_hub_2() {
+// ANCHOR: book_hub_2
+use candle::Device;
+use hf_hub::api::sync::Api;
+use memmap2::Mmap;
+use std::fs;
+
+let api = Api::new().unwrap();
+let repo = api.model("bert-base-uncased".to_string());
+let weights_filename = repo.get("model.safetensors").unwrap();
+
+let file = fs::File::open(weights_filename).unwrap();
+let mmap = unsafe { Mmap::map(&file).unwrap() };
+let weights = candle::safetensors::load_buffer(&mmap[..], &Device::Cpu).unwrap();
+// ANCHOR_END: book_hub_2
+        assert_eq!(weights.len(), 206);
+    }
+
+    #[rustfmt::skip]
+    #[test]
+    fn book_hub_3() {
+// ANCHOR: book_hub_3
+use candle::{DType, Device, Tensor};
+use hf_hub::api::sync::Api;
+use memmap2::Mmap;
+use safetensors::slice::IndexOp;
+use safetensors::SafeTensors;
+use std::fs;
+
+let api = Api::new().unwrap();
+let repo = api.model("bert-base-uncased".to_string());
+let weights_filename = repo.get("model.safetensors").unwrap();
+
+let file = fs::File::open(weights_filename).unwrap();
+let mmap = unsafe { Mmap::map(&file).unwrap() };
+
+// Use safetensors directly
+let tensors = SafeTensors::deserialize(&mmap[..]).unwrap();
+let view = tensors
+    .tensor("bert.encoder.layer.0.attention.self.query.weight")
+    .unwrap();
+
+// We're going to load shard with rank 1, within a world_size of 4
+// We're going to split along dimension 0 doing VIEW[start..stop, :]
+let rank = 1;
+let world_size = 4;
+let dim = 0;
+let dtype = view.dtype();
+let mut tp_shape = view.shape().to_vec();
+let size = tp_shape[0];
+
+if size % world_size != 0 {
+    panic!("The dimension is not divisble by `world_size`");
+}
+let block_size = size / world_size;
+let start = rank * block_size;
+let stop = (rank + 1) * block_size;
+
+// Everything is expressed in tensor dimension
+// bytes offsets is handled automatically for safetensors.
+
+let iterator = view.slice(start..stop).unwrap();
+
+tp_shape[dim] = block_size;
+
+// Convert safetensors Dtype to candle DType
+let dtype: DType = dtype.try_into().unwrap();
+
+// TODO: Implement from_buffer_iterator so we can skip the extra CPU alloc.
+let raw: Vec<u8> = iterator.into_iter().flatten().cloned().collect();
+let tp_tensor = Tensor::from_raw_buffer(&raw, dtype, &tp_shape, &Device::Cpu).unwrap();
+// ANCHOR_END: book_hub_3
+        assert_eq!(view.shape(), &[768, 768]);
+        assert_eq!(tp_tensor.dims(), &[192, 768]);
+    }
+}