Merge pull request #19 from LaurentMazare/llama_safetensors

Llama safetensors
This commit is contained in:
Nicolas Patry
2023-06-29 12:49:26 +02:00
committed by GitHub
6 changed files with 344 additions and 100 deletions

View File

@ -15,11 +15,12 @@ use anyhow::{Error as E, Result};
use clap::Parser;
use candle::{DType, Device, Tensor};
use candle_hub::{api::Api, Repo, RepoType};
use std::collections::HashMap;
use std::sync::{Arc, Mutex};
mod var_store;
use var_store::VarBuilder;
mod weights;
const CONTEXT_SIZE: usize = 512;
const START_PROMPT: &str = r"
@ -131,9 +132,8 @@ struct Embedding {
}
impl Embedding {
fn new(mut vb: VarBuilder, vocab_size: usize, n_embd: usize) -> Result<Self> {
let embeddings = vb.var("weight", (vocab_size, n_embd))?;
Ok(Self { embeddings })
fn new(embeddings: Tensor) -> Self {
Self { embeddings }
}
fn forward(&self, indexes: &Tensor) -> Result<Tensor> {
@ -145,42 +145,27 @@ impl Embedding {
}
struct Linear {
ws: Tensor,
bs: Option<Tensor>,
weight: Tensor,
}
impl Linear {
#[allow(dead_code)]
fn new(mut vb: VarBuilder, in_size: usize, out_size: usize) -> Result<Self> {
let ws = vb.var("weight", (in_size, out_size))?;
let bs = vb.var("bias", out_size)?;
Ok(Self { ws, bs: Some(bs) })
}
fn new_no_bias(mut vb: VarBuilder, in_size: usize, out_size: usize) -> Result<Self> {
let ws = vb.var("weight", (in_size, out_size))?;
Ok(Self { ws, bs: None })
fn new(weight: Tensor) -> Self {
Self { weight }
}
fn forward(&self, x: &Tensor) -> Result<Tensor> {
let x = x.matmul(&self.ws.to_dtype(DType::F32)?)?;
let y = match &self.bs {
None => x,
Some(bs) => x.broadcast_add(&bs.to_dtype(DType::F32)?)?,
};
Ok(y)
let x = x.matmul(&self.weight.to_dtype(DType::F32)?.t()?)?;
Ok(x)
}
}
struct RmsNorm {
scale: Tensor,
size: usize,
}
impl RmsNorm {
fn new(mut vb: VarBuilder, size: usize) -> Result<Self> {
let scale = vb.var("scale", &[size])?;
Ok(Self { scale, size })
fn new(scale: Tensor) -> Self {
Self { scale }
}
fn forward(&self, x: &Tensor) -> Result<Tensor> {
@ -188,10 +173,11 @@ impl RmsNorm {
let norm_x = ((x * x)?.sum(&[1])? / hidden_size as f64)?;
let norm_x = norm_x.broadcast_as((seq_len, hidden_size))?;
let x_normed = (x / (norm_x + 1e-5)?.sqrt()?)?;
let size = self.scale.shape().r1()?;
let scale = self
.scale
.to_dtype(DType::F32)?
.broadcast_as((seq_len, self.size))?;
.broadcast_as((seq_len, size))?;
Ok((scale * x_normed)?)
}
}
@ -207,17 +193,12 @@ fn silu(xs: &Tensor) -> Result<Tensor> {
}
impl Mlp {
fn new(vb: VarBuilder, n_embd: usize) -> Result<Self> {
let n_hidden = 8 * n_embd / 3;
let n_hidden = (n_hidden - 1) / 256 * 256 + 256;
let c_fc1 = Linear::new_no_bias(&vb / "c_fc1", n_embd, n_hidden)?;
let c_fc2 = Linear::new_no_bias(&vb / "c_fc2", n_embd, n_hidden)?;
let c_proj = Linear::new_no_bias(&vb / "c_proj", n_hidden, n_embd)?;
Ok(Self {
fn new(c_fc1: Linear, c_fc2: Linear, c_proj: Linear) -> Self {
Self {
c_fc1,
c_fc2,
c_proj,
})
}
}
fn forward(&self, x: &Tensor) -> Result<Tensor> {
@ -256,10 +237,6 @@ impl Cache {
let mask: Vec<_> = (0..t)
.flat_map(|i| (0..t).map(move |j| u32::from(j > i)))
.collect();
// Once lower_triangle is available, use the following:
//let mask = Tensor::new(1u32, &device)?
// .broadcast_as(&[t, t])?
// .lower_triangle()?
let mask = Tensor::from_slice(&mask, (t, t), &self.device)?;
masks.insert(t, mask.clone());
Ok(mask)
@ -271,21 +248,18 @@ struct CausalSelfAttention {
c_attn: Linear,
c_proj: Linear,
n_head: usize,
n_embd: usize,
// n_embd: usize,
cache: Cache,
}
impl CausalSelfAttention {
fn new(vb: VarBuilder, n_head: usize, n_embd: usize, cache: &Cache) -> Result<Self> {
let c_attn = Linear::new_no_bias(&vb / "c_attn", n_embd, 3 * n_embd)?;
let c_proj = Linear::new_no_bias(&vb / "c_proj", n_embd, n_embd)?;
Ok(Self {
fn new(c_attn: Linear, c_proj: Linear, n_head: usize, cache: &Cache) -> Self {
Self {
c_attn,
c_proj,
n_head,
n_embd,
cache: cache.clone(),
})
}
}
fn apply_rotary_emb(&self, x: &Tensor, freqs_cis: &Tensor) -> Result<Tensor> {
@ -313,7 +287,7 @@ impl CausalSelfAttention {
fn forward(&self, x: &Tensor, freqs_cis: &Tensor) -> Result<Tensor> {
let (t, c) = x.shape().r2()?;
let qkv = self.c_attn.forward(x)?;
let n_embd = self.n_embd;
let n_embd = c;
let q = qkv.narrow(1, 0, n_embd)?;
let k = qkv.narrow(1, n_embd, n_embd)?;
let v = qkv.narrow(1, 2 * n_embd, n_embd)?;
@ -344,17 +318,13 @@ struct Block {
}
impl Block {
fn new(vb: VarBuilder, cache: &Cache, config: &Config) -> Result<Self> {
let rms_1 = RmsNorm::new(&vb / "rms_1", config.n_embd)?;
let attn = CausalSelfAttention::new(&vb / "attn", config.n_head, config.n_embd, cache)?;
let rms_2 = RmsNorm::new(&vb / "rms_2", config.n_embd)?;
let mlp = Mlp::new(&vb / "mlp", config.n_embd)?;
Ok(Self {
fn new(rms_1: RmsNorm, attn: CausalSelfAttention, rms_2: RmsNorm, mlp: Mlp) -> Self {
Self {
rms_1,
attn,
rms_2,
mlp,
})
}
}
fn forward(&self, x: &Tensor, freqs_cis: &Tensor) -> Result<Tensor> {
@ -372,23 +342,13 @@ struct Llama {
}
impl Llama {
fn new(vb: VarBuilder, cache: &Cache, config: &Config) -> Result<Self> {
let lm_head = Linear::new_no_bias(&vb / "lm_head", config.n_embd, config.vocab_size)?;
let wte = Embedding::new(
&vb / "transformer" / "wte",
config.vocab_size,
config.n_embd,
)?;
let blocks = (0..config.n_layer)
.map(|i| Block::new(&vb / "transformer" / "h" / i, cache, config))
.collect::<Result<Vec<_>>>()?;
let ln_f = RmsNorm::new(&vb / "transformer" / "ln_f", config.n_embd)?;
Ok(Self {
fn new(wte: Embedding, blocks: Vec<Block>, ln_f: RmsNorm, lm_head: Linear) -> Self {
Self {
wte,
blocks,
ln_f,
lm_head,
})
}
}
fn forward(&self, x: &Tensor, freqs_cis: &Tensor) -> Result<Tensor> {
@ -434,6 +394,10 @@ struct Args {
#[arg(long)]
cpu: bool,
/// Use npy instead of safetensors
#[arg(long)]
npy: bool,
/// The temperature used to generate samples.
#[arg(long, default_value_t = 1.0)]
temperature: f64,
@ -443,8 +407,9 @@ struct Args {
sample_len: usize,
}
fn main() -> Result<()> {
use rand::prelude::*;
#[tokio::main]
async fn main() -> Result<()> {
//use rand::prelude::*;
use tokenizers::Tokenizer;
let args = Args::parse();
@ -453,38 +418,44 @@ fn main() -> Result<()> {
} else {
Device::new_cuda(0)?
};
println!("loading tokenizer config");
let tokenizer = Tokenizer::from_file("llama-tokenizer.json").map_err(E::msg)?;
let api = Api::new()?;
let repo = Repo::new("Narsil/amall-7b".to_string(), RepoType::Model);
let tokenizer_filename = api.get(&repo, "tokenizer.json").await?;
println!("Filename {tokenizer_filename:?}");
let tokenizer = Tokenizer::from_file(tokenizer_filename).map_err(E::msg)?;
let mut tokens = tokenizer
.encode(START_PROMPT, true)
.map_err(E::msg)?
.get_ids()
.to_vec();
let weight_path = std::path::Path::new("llama.npz");
let weights = if weight_path.exists() {
println!("loading weights from {weight_path:?}");
let start_load = std::time::Instant::now();
let tensors = Tensor::read_npz(weight_path)?;
println!("loaded weights in {:?}", start_load.elapsed());
let tensors: std::collections::HashMap<String, Tensor> = tensors.into_iter().collect();
Some(tensors)
} else {
println!("cannot find {weight_path:?}, using zero weights");
None
};
let vb = VarBuilder::new::<f32>(&device, weights);
let mut filenames = vec![];
for rfilename in [
"model-00001-of-00002.safetensors",
"model-00002-of-00002.safetensors",
] {
let filename = api.get(&repo, rfilename).await?;
filenames.push(filename);
}
println!("building the model");
let config = Config::config_7b();
let cache = Cache::new(&device);
let llama = Llama::new(vb, &cache, &config)?;
let start = std::time::Instant::now();
let llama = if args.npy {
println!("building the model (NPY)");
Llama::load_npy(&device, &filenames, &cache, &config)?
} else {
println!("building the model (SF)");
Llama::load(&device, &filenames, &cache, &config)?
};
println!("Loaded in {:?}", start.elapsed());
println!("pre-computing the positional embeddings");
let freqs_cis = precompute_freqs_cis(&config, &device)?;
println!("starting the inference loop");
let mut new_tokens = vec![];
let mut rng = thread_rng();
//let mut rng = thread_rng();
let start_gen = std::time::Instant::now();
for index in 0..args.sample_len {
let start_gen = std::time::Instant::now();
@ -493,8 +464,20 @@ fn main() -> Result<()> {
let logits = llama.forward(&input, &freqs_cis)?;
let prs = (&logits / args.temperature)?.softmax(logits.rank() - 1)?;
let logits_v: Vec<f32> = prs.to_vec1()?;
let distr = rand::distributions::WeightedIndex::new(&logits_v)?;
let next_token = distr.sample(&mut rng) as u32;
let next_token = logits_v
.iter()
.enumerate()
.fold((0, logits_v[0]), |(idx_max, val_max), (idx, val)| {
if &val_max > val {
(idx_max, val_max)
} else {
(idx, *val)
}
})
.0 as u32;
// let distr = rand::distributions::WeightedIndex::new(&logits_v)?;
// let next_token = distr.sample(&mut rng) as u32;
tokens.push(next_token);
new_tokens.push(next_token);
println!("> {:?}", start_gen.elapsed());