Result: Getting the weather for San Francisco, CA in fahrenheit...
```
This example demonstrates:
- Setting up the server with tool calling enabled
- Defining an actual function to handle tool calls
- Making a request with `tool_choice="auto"`
- Handling the structured response and executing the corresponding function
* Setting up the server with tool calling enabled
* Defining an actual function to handle tool calls
* Making a request with `tool_choice="auto"`
* Handling the structured response and executing the corresponding function
You can also specify a particular function using named function calling by setting `tool_choice={"type": "function", "function": {"name": "get_weather"}}`. Note that this will use the guided decoding backend - so the first time this is used, there will be several seconds of latency (or more) as the FSM is compiled for the first time before it is cached for subsequent requests.
Remember that it's the callers responsibility to:
1. Define appropriate tools in the request
2. Include relevant context in the chat messages
3. Handle the tool calls in your application logic
...
...
@@ -77,20 +80,21 @@ Remember that it's the callers responsibility to:
For more advanced usage, including parallel tool calls and different model-specific parsers, see the sections below.
## Named Function Calling
vLLM supports named function calling in the chat completion API by default. It does so using Outlines through guided decoding, so this is
enabled by default, and will work with any supported model. You are guaranteed a validly-parsable function call - not a
high-quality one.
vLLM will use guided decoding to ensure the response matches the tool parameter object defined by the JSON schema in the `tools` parameter.
vLLM will use guided decoding to ensure the response matches the tool parameter object defined by the JSON schema in the `tools` parameter.
For best results, we recommend ensuring that the expected output format / schema is specified in the prompt to ensure that the model's intended generation is aligned with the schema that it's being forced to generate by the guided decoding backend.
To use a named function, you need to define the functions in the `tools` parameter of the chat completion request, and
specify the `name` of one of the tools in the `tool_choice` parameter of the chat completion request.
## Automatic Function Calling
To enable this feature, you should set the following flags:
* `--enable-auto-tool-choice` -- **mandatory** Auto tool choice. tells vLLM that you want to enable the model to generate its own tool calls when it
deems appropriate.
* `--tool-call-parser` -- select the tool parser to use (listed below). Additional tool parsers
...
...
@@ -104,28 +108,28 @@ from HuggingFace; and you can find an example of this in a `tokenizer_config.jso
If your favorite tool-calling model is not supported, please feel free to contribute a parser & tool use chat template!
### Hermes Models (`hermes`)
All Nous Research Hermes-series models newer than Hermes 2 Pro should be supported.
* `NousResearch/Hermes-2-Pro-*`
* `NousResearch/Hermes-2-Theta-*`
* `NousResearch/Hermes-3-*`
_Note that the Hermes 2 **Theta** models are known to have degraded tool call quality & capabilities due to the merge
`examples/tool_chat_template_granite_20b_fc.jinja`: this is a modified chat template from the original on Huggingface, which is not vLLM compatible. It blends function description elements from the Hermes template and follows the same system prompt as "Response Generation" mode from [the paper](https://arxiv.org/abs/2407.00121). Parallel function calls are supported.
### InternLM Models (`internlm`)
Supported models:
* `internlm/internlm2_5-7b-chat` (confirmed)
* Additional internlm2.5 function-calling models are compatible as well
Known issues:
* Although this implementation also supports InternLM2, the tool call results are not stable when testing with the `internlm/internlm2-chat-7b` model.
A growing number of models output a python list to represent tool calls instead of using JSON. This has the advantage of inherently supporting parallel tool calls and removing ambiguity around the JSON schema required for tool calls. The `pythonic` tool parser can support such models.
As a concrete example, these models may look up the weather in San Francisco and Seattle by generating:
* The model must not generate both text and tool calls in the same generation. This may not be hard to change for a specific model, but the community currently lacks consensus on which tokens to emit when starting and ending tool calls. (In particular, the Llama 3.2 models emit no such tokens.)
* Llama's smaller models struggle to use tools effectively.
Example supported models:
* `meta-llama/Llama-3.2-1B-Instruct`\* (use with `examples/tool_chat_template_llama3.2_pythonic.jinja`)
* `meta-llama/Llama-3.2-3B-Instruct`\* (use with `examples/tool_chat_template_llama3.2_pythonic.jinja`)
* `Team-ACE/ToolACE-8B` (use with `examples/tool_chat_template_toolace.jinja`)
...
...
@@ -231,7 +239,6 @@ Llama's smaller models frequently fail to emit tool calls in the correct format.
---
## How to write a tool parser plugin
A tool parser plugin is a Python file containing one or more ToolParser implementations. You can write a ToolParser similar to the `Hermes2ProToolParser` in vllm/entrypoints/openai/tool_parsers/hermes_tool_parser.py.
...
...
@@ -284,7 +291,8 @@ class ExampleToolParser(ToolParser):
```
Then you can use this plugin in the command line like this.
```
```console
--enable-auto-tool-choice \
--tool-parser-plugin <absolute path of the plugin file>
"A collection of examples demonstrating usage of vLLM.\nAll documented examples are autogenerated using <gh-file:docs/source/generate_examples.py> from examples found in <gh-file:examples>.",# noqa: E501
caption="Examples",
maxdepth=2)
# Category indices stored in reverse order because they are inserted into
# examples_index.documents at index 0 in order
category_indices={
"other":
Index(
path=EXAMPLE_DOC_DIR/"examples_other_index.md",
title="Other",
description=
"Other examples that don't strongly fit into the online or offline serving categories.",# noqa: E501
vLLM has been adapted to work on ARM64 CPUs with NEON support, leveraging the CPU backend initially developed for the x86 platform. This guide provides installation instructions specific to ARM. For additional details on supported features, refer to the x86 platform documentation covering:
- CPU backend inference capabilities
- Relevant runtime environment variables
- Performance optimization tips
ARM CPU backend currently supports Float32, FP16 and BFloat16 datatypes.
Contents:
1.[Requirements](#arm-backend-requirements)
2.[Quick Start with Dockerfile](#arm-backend-quick-start-dockerfile)
3.[Building from Source](#build-arm-backend-from-source)
(arm-backend-requirements)=
## Requirements
-**Operating System**: Linux or macOS
-**Compiler**: gcc/g++ >= 12.3.0 (optional, but recommended)
-**Instruction Set Architecture (ISA)**: NEON support is required
To build vLLM from source on Ubuntu 22.04 or other Linux distributions, follow a similar process as with x86. Testing has been conducted on AWS Graviton3 instances for compatibility.
$docker run -it--runtime=habana -eHABANA_VISIBLE_DEVICES=all -eOMPI_MCA_btl_vader_single_copy_mechanism=none --cap-add=sys_nice --net=host --rm vllm-hpu-env
```
```{tip}
If you're observing the following error: `docker: Error response from daemon: Unknown runtime specified habana.`, please refer to "Install Using Containers" section of [Intel Gaudi Software Stack and Driver Installation](https://docs.habana.ai/en/v1.18.0/Installation_Guide/Bare_Metal_Fresh_OS.html). Make sure you have `habana-container-runtime` package installed and that `habana` container runtime is registered.
```
Please follow the instructions provided in the [Gaudi Installation
To verify that the Intel Gaudi software was correctly installed, run:
```console
$hl-smi # verify that hl-smi is in your PATH and each Gaudi accelerator is visible
$apt list --installed | grep habana # verify that habanalabs-firmware-tools, habanalabs-graph, habanalabs-rdma-core, habanalabs-thunk and habanalabs-container-runtime are installed
$pip list | grep habana # verify that habana-torch-plugin, habana-torch-dataloader, habana-pyhlml and habana-media-loader are installed
$pip list | grep neural # verify that neural_compressor is installed
hl-smi #verify that hl-smi is in your PATH and each Gaudi accelerator is visible
apt list --installed | grep habana #verify that habanalabs-firmware-tools, habanalabs-graph, habanalabs-rdma-core, habanalabs-thunk and habanalabs-container-runtime are installed
pip list | grep habana #verify that habana-torch-plugin, habana-torch-dataloader, habana-pyhlml and habana-media-loader are installed
pip list | grep neural #verify that neural_compressor is installed
Currently, the latest features and performance optimizations are developed in Gaudi's [vLLM-fork](https://github.com/HabanaAI/vllm-fork) and we periodically upstream them to vLLM main repo. To install latest [HabanaAI/vLLM-fork](https://github.com/HabanaAI/vllm-fork), run the following:
If you're observing the following error: `docker: Error response from daemon: Unknown runtime specified habana.`, please refer to "Install Using Containers" section of [Intel Gaudi Software Stack and Driver Installation](https://docs.habana.ai/en/v1.18.0/Installation_Guide/Bare_Metal_Fresh_OS.html). Make sure you have `habana-container-runtime` package installed and that `habana` container runtime is registered.
:::
## Extra information
## Supported features
-[Offline inference](#offline-inference)
- Online serving via [OpenAI-Compatible Server](#openai-compatible-server)
- HPU autodetection - no need to manually select device within vLLM
- Paged KV cache with algorithms enabled for Intel Gaudi accelerators
with tensor parallelism on 8x HPU, BF16 datatype with random or greedy sampling
## Performance Tuning
## Performance tuning
### Execution modes
Currently in vLLM for HPU we support four execution modes, depending on selected HPU PyTorch Bridge backend (via `PT_HPU_LAZY_MODE` environment variable), and `--enforce-eager` flag.
```{eval-rst}
.. list-table:: vLLM execution modes
:widths: 25 25 50
:header-rows: 1
* - ``PT_HPU_LAZY_MODE``
- ``enforce_eager``
- execution mode
* - 0
- 0
- torch.compile
* - 0
- 1
- PyTorch eager mode
* - 1
- 0
- HPU Graphs
* - 1
- 1
- PyTorch lazy mode
```
```{warning}
:::{list-table} vLLM execution modes
:widths: 25 25 50
:header-rows: 1
-*`PT_HPU_LAZY_MODE`
*`enforce_eager`
* execution mode
-* 0
* 0
* torch.compile
-* 0
* 1
* PyTorch eager mode
-* 1
* 0
* HPU Graphs
-* 1
* 1
* PyTorch lazy mode
:::
:::{warning}
In 1.18.0, all modes utilizing `PT_HPU_LAZY_MODE=0` are highly experimental and should be only used for validating functional correctness. Their performance will be improved in the next releases. For obtaining the best performance in 1.18.0, please use HPU Graphs, or PyTorch lazy mode.
```
:::
(gaudi-bucketing-mechanism)=
### Bucketing mechanism
Intel Gaudi accelerators work best when operating on models with fixed tensor shapes. [Intel Gaudi Graph Compiler](https://docs.habana.ai/en/latest/Gaudi_Overview/Intel_Gaudi_Software_Suite.html#graph-compiler-and-runtime) is responsible for generating optimized binary code that implements the given model topology on Gaudi. In its default configuration, the produced binary code may be heavily dependent on input and output tensor shapes, and can require graph recompilation when encountering differently shaped tensors within the same topology. While the resulting binaries utilize Gaudi efficiently, the compilation itself may introduce a noticeable overhead in end-to-end execution.
In a dynamic inference serving scenario, there is a need to minimize the number of graph compilations and reduce the risk of graph compilation occurring during server runtime. Currently it is achieved by "bucketing" model's forward pass across two dimensions - `batch_size` and `sequence_length`.
```{note}
:::{note}
Bucketing allows us to reduce the number of required graphs significantly, but it does not handle any graph compilation and device code generation - this is done in warmup and HPUGraph capture phase.
```
:::
Bucketing ranges are determined with 3 parameters - `min`, `step` and `max`. They can be set separately for prompt and decode phase, and for batch size and sequence length dimension. These parameters can be observed in logs during vLLM startup:
`min` determines the lowest value of the bucket. `step` determines the interval between buckets, and `max` determines the upper bound of the bucket. Furthermore, interval between `min` and `step` has special handling - `min` gets multiplied by consecutive powers of two, until `step` gets reached. We call this the ramp-up phase and it is used for handling lower batch sizes with minimum wastage, while allowing larger padding on larger batch sizes.
`min` determines the lowest value of the bucket. `step` determines the interval between buckets, and `max` determines the upper bound of the bucket. Furthermore, interval between `min` and `step` has special handling --`min` gets multiplied by consecutive powers of two, until `step` gets reached. We call this the ramp-up phase and it is used for handling lower batch sizes with minimum wastage, while allowing larger padding on larger batch sizes.
Example (with ramp-up)
```
```text
min = 2, step = 32, max = 64
=> ramp_up = (2, 4, 8, 16)
=> stable = (32, 64)
...
...
@@ -198,7 +217,7 @@ min = 2, step = 32, max = 64
Example (without ramp-up)
```
```text
min = 128, step = 128, max = 512
=> ramp_up = ()
=> stable = (128, 256, 384, 512)
...
...
@@ -207,21 +226,21 @@ min = 128, step = 128, max = 512
In the logged scenario, 24 buckets were generated for prompt (prefill) runs, and 48 buckets for decode runs. Each bucket corresponds to a separate optimized device binary for a given model with specified tensor shapes. Whenever a batch of requests is processed, it is padded across batch and sequence length dimension to the smallest possible bucket.
```{warning}
:::{warning}
If a request exceeds maximum bucket size in any dimension, it will be processed without padding, and its processing may require a graph compilation, potentially significantly increasing end-to-end latency. The boundaries of the buckets are user-configurable via environment variables, and upper bucket boundaries can be increased to avoid such scenario.
```
:::
As an example, if a request of 3 sequences, with max sequence length of 412 comes in to an idle vLLM server, it will be padded executed as `(4, 512)` prefill bucket, as `batch_size` (number of sequences) will be padded to 4 (closest batch_size dimension higher than 3), and max sequence length will be padded to 512 (closest sequence length dimension higher than 412). After prefill stage, it will be executed as `(4, 512)` decode bucket and will continue as that bucket until either batch dimension changes (due to request being finished) - in which case it will become a `(2, 512)` bucket, or context length increases above 512 tokens, in which case it will become `(4, 640)` bucket.
```{note}
Bucketing is transparent to a client - padding in sequence length dimension is never returned to the client, and padding in batch dimension does not create new requests.
```
:::{note}
Bucketing is transparent to a client -- padding in sequence length dimension is never returned to the client, and padding in batch dimension does not create new requests.
:::
### Warmup
Warmup is an optional, but highly recommended step occurring before vLLM server starts listening. It executes a forward pass for each bucket with dummy data. The goal is to pre-compile all graphs and not incur any graph compilation overheads within bucket boundaries during server runtime. Each warmup step is logged during vLLM startup:
```
```text
INFO 08-01 22:26:47 hpu_model_runner.py:1066] [Warmup][Prompt][1/24] batch_size:4 seq_len:1024 free_mem:79.16 GiB
INFO 08-01 22:26:47 hpu_model_runner.py:1066] [Warmup][Prompt][2/24] batch_size:4 seq_len:896 free_mem:55.43 GiB
INFO 08-01 22:26:48 hpu_model_runner.py:1066] [Warmup][Prompt][3/24] batch_size:4 seq_len:768 free_mem:55.43 GiB
...
...
@@ -235,11 +254,11 @@ INFO 08-01 22:27:16 hpu_model_runner.py:1066] [Warmup][Decode][47/48] batch_size
INFO 08-01 22:27:16 hpu_model_runner.py:1066] [Warmup][Decode][48/48] batch_size:1 seq_len:128 free_mem:55.43 GiB
```
This example uses the same buckets as in *Bucketing mechanism* section. Each output line corresponds to execution of a single bucket. When bucket is executed for the first time, its graph is compiled and can be reused later on, skipping further graph compilations.
This example uses the same buckets as in the [Bucketing Mechanism](#gaudi-bucketing-mechanism) section. Each output line corresponds to execution of a single bucket. When bucket is executed for the first time, its graph is compiled and can be reused later on, skipping further graph compilations.
```{tip}
:::{tip}
Compiling all the buckets might take some time and can be turned off with `VLLM_SKIP_WARMUP=true` environment variable. Keep in mind that if you do that, you may face graph compilations once executing a given bucket for the first time. It is fine to disable warmup for development, but it's highly recommended to enable it in deployment.
```
:::
### HPU Graph capture
...
...
@@ -254,9 +273,9 @@ With its default value (`VLLM_GRAPH_RESERVED_MEM=0.1`), 10% of usable memory wil
Environment variable `VLLM_GRAPH_PROMPT_RATIO` determines the ratio of usable graph memory reserved for prefill and decode graphs. By default (`VLLM_GRAPH_PROMPT_RATIO=0.3`), both stages have equal memory constraints.
Lower value corresponds to less usable graph memory reserved for prefill stage, e.g. `VLLM_GRAPH_PROMPT_RATIO=0.2` will reserve 20% of usable graph memory for prefill graphs, and 80% of usable graph memory for decode graphs.
```{note}
:::{note}
`gpu_memory_utilization` does not correspond to the absolute memory usage across HPU. It specifies the memory margin after loading the model and performing a profile run. If device has 100 GiB of total memory, and 50 GiB of free memory after loading model weights and executing profiling run, `gpu_memory_utilization` at its default value will mark 90% of 50 GiB as usable, leaving 5 GiB of margin, regardless of total device memory.
```
:::
User can also configure the strategy for capturing HPU Graphs for prompt and decode stages separately. Strategy affects the order of capturing graphs. There are two strategies implemented:
\-`max_bs` - graph capture queue will sorted in descending order by their batch sizes. Buckets with equal batch sizes are sorted by sequence length in ascending order (e.g. `(64, 128)`, `(64, 256)`, `(32, 128)`, `(32, 256)`, `(1, 128)`, `(1,256)`), default strategy for decode
...
...
@@ -264,13 +283,13 @@ User can also configure the strategy for capturing HPU Graphs for prompt and dec
When there's large amount of requests pending, vLLM scheduler will attempt to fill the maximum batch size for decode as soon as possible. When a request is finished, decode batch size decreases. When that happens, vLLM will attempt to schedule a prefill iteration for requests in the waiting queue, to fill the decode batch size to its previous state. This means that in a full load scenario, decode batch size is often at its maximum, which makes large batch size HPU Graphs crucial to capture, as reflected by `max_bs` strategy. On the other hand, prefills will be executed most frequently with very low batch sizes (1-4), which is reflected in `min_tokens` strategy.
```{note}
:::{note}
`VLLM_GRAPH_PROMPT_RATIO` does not set a hard limit on memory taken by graphs for each stage (prefill and decode). vLLM will first attempt to use up entirety of usable prefill graph memory (usable graph memory *`VLLM_GRAPH_PROMPT_RATIO`) for capturing prefill HPU Graphs, next it will attempt do the same for decode graphs and usable decode graph memory pool. If one stage is fully captured, and there is unused memory left within usable graph memory pool, vLLM will attempt further graph capture for the other stage, until no more HPU Graphs can be captured without exceeding reserved memory pool. The behavior on that mechanism can be observed in the example below.
```
:::
Each described step is logged by vLLM server, as follows (negative values correspond to memory being released):
-[Step 1. Install drivers and tools](#install-drivers)
-[Step 2. Install transformers-neuronx and its dependencies](#install-tnx)
-[Step 3. Install vLLM from source](#install-vllm)
(build-from-source-neuron)=
```{note}
The currently supported version of Pytorch for Neuron installs `triton` version `2.1.0`. This is incompatible with vLLM >= 0.5.3. You may see an error `cannot import name 'default_dump_dir...`. To work around this, run a `pip install --upgrade triton==3.0.0` after installing the vLLM wheel.
```
## Build from source
Following instructions are applicable to Neuron SDK 2.16 and beyond.
(launch-instances)=
## Configure a new environment
### Step 0. Launch Trn1/Inf2 instances
### Launch Trn1/Inf2 instances
Here are the steps to launch trn1/inf2 instances, in order to install [PyTorch Neuron ("torch-neuronx") Setup on Ubuntu 22.04 LTS](https://awsdocs-neuron.readthedocs-hosted.com/en/latest/general/setup/neuron-setup/pytorch/neuronx/ubuntu/torch-neuronx-ubuntu22.html).
...
...
@@ -45,9 +28,7 @@ Here are the steps to launch trn1/inf2 instances, in order to install [PyTorch N
- When launching a Trn1/Inf2, please adjust your primary EBS volume size to a minimum of 512GB.
- After launching the instance, follow the instructions in [Connect to your instance](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AccessingInstancesLinux.html) to connect to the instance
(install-drivers)=
### Step 1. Install drivers and tools
### Install drivers and tools
The installation of drivers and tools wouldn't be necessary, if [Deep Learning AMI Neuron](https://docs.aws.amazon.com/dlami/latest/devguide/appendix-ami-release-notes.html) is installed. In case the drivers and tools are not installed on the operating system, follow the steps below:
### Step 2. Install transformers-neuronx and its dependencies
### Build wheel from source
:::{note}
The currently supported version of Pytorch for Neuron installs `triton` version `2.1.0`. This is incompatible with `vllm >= 0.5.3`. You may see an error `cannot import name 'default_dump_dir...`. To work around this, run a `pip install --upgrade triton==3.0.0` after installing the vLLM wheel.
:::
Following instructions are applicable to Neuron SDK 2.16 and beyond.
#### Install transformers-neuronx and its dependencies
[transformers-neuronx](https://github.com/aws-neuron/transformers-neuronx) will be the backend to support inference on trn1/inf2 instances.
Follow the steps below to install transformer-neuronx package and its dependencies.
vLLM powered by OpenVINO supports all LLM models from [vLLM supported models list](#supported-models) and can perform optimal model serving on all x86-64 CPUs with, at least, AVX2 support, as well as on both integrated and discrete Intel® GPUs ([the list of supported GPUs](https://docs.openvino.ai/2024/about-openvino/release-notes-openvino/system-requirements.html#gpu)).
vLLM powered by OpenVINO supports all LLM models from {doc}`vLLM supported models list <../models/supported_models>` and can perform optimal model serving on all x86-64 CPUs with, at least, AVX2 support, as well as on both integrated and discrete Intel® GPUs ([the list of supported GPUs](https://docs.openvino.ai/2024/about-openvino/release-notes-openvino/system-requirements.html#gpu)). OpenVINO vLLM backend supports the following advanced vLLM features:
:::{attention}
There are no pre-built wheels or images for this device, so you must build vLLM from source.
:::
- Prefix caching (`--enable-prefix-caching`)
- Chunked prefill (`--enable-chunked-prefill`)
## Requirements
- OS: Linux
- Instruction set architecture (ISA) requirement: at least AVX2.
**Table of contents**:
## Set up using Python
-[Requirements](#openvino-backend-requirements)
-[Quick start using Dockerfile](#openvino-backend-quick-start-dockerfile)
-[Build from source](#install-openvino-backend-from-source)
To use vLLM OpenVINO backend with a GPU device, ensure your system is properly set up. Follow the instructions provided here: [https://docs.openvino.ai/2024/get-started/configurations/configurations-intel-gpu.html](https://docs.openvino.ai/2024/get-started/configurations/configurations-intel-gpu.html).
:::
## Install from source
## Set up using Docker
- First, install Python. For example, on Ubuntu 22.04, you can run:
### Pre-built images
```console
$sudo apt-get update -y
$sudo apt-get install python3
```
Currently, there are no pre-built OpenVINO images.
-[Optional] To use vLLM OpenVINO backend with a GPU device, ensure your system is properly set up. Follow the instructions provided here: [https://docs.openvino.ai/2024/get-started/configurations/configurations-intel-gpu.html](https://docs.openvino.ai/2024/get-started/configurations/configurations-intel-gpu.html).
OpenVINO vLLM backend supports the following advanced vLLM features:
See <project:#deployment-docker-pre-built-image> for instructions on using the official Docker image, making sure to substitute the image name `vllm/vllm-openai` with `vllm/vllm-tpu`.
## Build a docker image with {code}`Dockerfile.tpu`
### Build image from source
You can use <gh-file:Dockerfile.tpu> to build a Docker image with TPU support.
```console
$docker build -f Dockerfile.tpu -t vllm-tpu .
docker build -f Dockerfile.tpu -t vllm-tpu .
```
Run the Docker image with the following command:
```console
$# Make sure to add `--privileged --net host --shm-size=16G`.
$docker run --privileged--net host --shm-size=16G -it vllm-tpu
#Make sure to add `--privileged--net host --shm-size=16G`.
docker run --privileged --net host --shm-size=16G -it vllm-tpu
```
```{note}
:::{note}
Since TPU relies on XLA which requires static shapes, vLLM bucketizes the
possible input shapes and compiles an XLA graph for each shape. The
compilation time may take 20~30 minutes in the first run. However, the
compilation time reduces to ~5 minutes afterwards because the XLA graphs are
cached in the disk (in {code}`VLLM_XLA_CACHE_PATH` or {code}`~/.cache/vllm/xla_cache` by default).
vLLM has experimental support for macOS with Apple silicon. For now, users shall build from the source vLLM to natively run on macOS.
Currently the CPU implementation for macOS supports FP32 and FP16 datatypes.
:::{attention}
There are no pre-built wheels or images for this device, so you must build vLLM from source.
:::
## Requirements
- OS: `macOS Sonoma` or later
- SDK: `XCode 15.4` or later with Command Line Tools
- Compiler: `Apple Clang >= 15.0.0`
## Set up using Python
### Pre-built wheels
### Build wheel from source
After installation of XCode and the Command Line Tools, which include Apple Clang, execute the following commands to build and install vLLM from the source.
First, install recommended compiler. We recommend to use `gcc/g++ >= 12.3.0` as the default compiler to avoid potential problems. For example, on Ubuntu 22.4, you can run:
vLLM is a Python library that supports the following CPU variants. Select your CPU type to see vendor specific instructions:
vLLM initially supports basic model inferencing and serving on x86 CPU platform, with data types FP32, FP16 and BF16. vLLM CPU backend supports the following vLLM features:
:::::{tab-set}
:sync-group: device
- Tensor Parallel
- Model Quantization (`INT8 W8A8, AWQ`)
- Chunked-prefill
- Prefix-caching
- FP8-E5M2 KV-Caching (TODO)
::::{tab-item} Intel/AMD x86
:selected:
:sync: x86
:::{include} x86.inc.md
:start-after: "# Installation"
:end-before: "## Requirements"
:::
::::
::::{tab-item} ARM AArch64
:sync: arm
:::{include} arm.inc.md
:start-after: "# Installation"
:end-before: "## Requirements"
:::
Table of contents:
::::
1.[Requirements](#cpu-backend-requirements)
2.[Quick start using Dockerfile](#cpu-backend-quick-start-dockerfile)
3.[Build from source](#build-cpu-backend-from-source)
- First, install recommended compiler. We recommend to use `gcc/g++ >= 12.3.0` as the default compiler to avoid potential problems. For example, on Ubuntu 22.4, you can run:
- AVX512_BF16 is an extension ISA provides native BF16 data type conversion and vector product instructions, will brings some performance improvement compared with pure AVX512. The CPU backend build script will check the host CPU flags to determine whether to enable AVX512_BF16.
- If you want to force enable AVX512_BF16 for the cross-compilation, please set environment variable VLLM_CPU_AVX512BF16=1 before the building.
```
vLLM CPU backend supports the following vLLM features:
(env-intro)=
- Tensor Parallel
- Model Quantization (`INT8 W8A8, AWQ, GPTQ`)
- Chunked-prefill
- Prefix-caching
- FP8-E5M2 KV-Caching (TODO)
## Related runtime environment variables
-`VLLM_CPU_KVCACHE_SPACE`: specify the KV Cache size (e.g, `VLLM_CPU_KVCACHE_SPACE=40` means 40 GB space for KV cache), larger setting will allow vLLM running more requests in parallel. This parameter should be set based on the hardware configuration and memory management pattern of users.
-`VLLM_CPU_OMP_THREADS_BIND`: specify the CPU cores dedicated to the OpenMP threads. For example, `VLLM_CPU_OMP_THREADS_BIND=0-31` means there will be 32 OpenMP threads bound on 0-31 CPU cores. `VLLM_CPU_OMP_THREADS_BIND=0-31|32-63` means there will be 2 tensor parallel processes, 32 OpenMP threads of rank0 are bound on 0-31 CPU cores, and the OpenMP threads of rank1 are bound on 32-63 CPU cores.
(ipex-guidance)=
## Intel Extension for PyTorch
-[Intel Extension for PyTorch (IPEX)](https://github.com/intel/intel-extension-for-pytorch) extends PyTorch with up-to-date features optimizations for an extra performance boost on Intel hardware.
(cpu-backend-performance-tips)=
## Performance tips
- We highly recommend to use TCMalloc for high performance memory allocation and better cache locality. For example, on Ubuntu 22.4, you can run:
- When using the online serving, it is recommended to reserve 1-2 CPU cores for the serving framework to avoid CPU oversubscription. For example, on a platform with 32 physical CPU cores, reserving CPU 30 and 31 for the framework and using CPU 0-29 for OpenMP:
```console
$export VLLM_CPU_KVCACHE_SPACE=40
$export VLLM_CPU_OMP_THREADS_BIND=0-29
$vllm serve facebook/opt-125m
export VLLM_CPU_KVCACHE_SPACE=40
export VLLM_CPU_OMP_THREADS_BIND=0-29
vllm serve facebook/opt-125m
```
- If using vLLM CPU backend on a machine with hyper-threading, it is recommended to bind only one OpenMP thread on each physical CPU core using `VLLM_CPU_OMP_THREADS_BIND`. On a hyper-threading enabled platform with 16 logical CPU cores / 8 physical CPU cores:
#On this platform, it is recommend to only bind openMP threads on logical CPU cores 0-7 or 8-15
$export VLLM_CPU_OMP_THREADS_BIND=0-7
$python examples/offline_inference.py
$python examples/offline_inference/basic.py
```
- If using vLLM CPU backend on a multi-socket machine with NUMA, be aware to set CPU cores using `VLLM_CPU_OMP_THREADS_BIND` to avoid cross NUMA node memory access.
## CPU Backend Considerations
## Other considerations
- The CPU backend significantly differs from the GPU backend since the vLLM architecture was originally optimized for GPU use. A number of optimizations are needed to enhance its performance.
- Decouple the HTTP serving components from the inference components. In a GPU backend configuration, the HTTP serving and tokenization tasks operate on the CPU, while inference runs on the GPU, which typically does not pose a problem. However, in a CPU-based setup, the HTTP serving and tokenization can cause significant context switching and reduced cache efficiency. Therefore, it is strongly recommended to segregate these two components for improved performance.
- On CPU based setup with NUMA enabled, the memory access performance may be largely impacted by the [topology](https://github.com/intel/intel-extension-for-pytorch/blob/main/docs/tutorials/performance_tuning/tuning_guide.md#non-uniform-memory-access-numa). For NUMA architecture, two optimizations are to recommended: Tensor Parallel or Data Parallel.
- On CPU based setup with NUMA enabled, the memory access performance may be largely impacted by the [topology](https://github.com/intel/intel-extension-for-pytorch/blob/main/docs/tutorials/performance_tuning/tuning_guide.inc.md#non-uniform-memory-access-numa). For NUMA architecture, two optimizations are to recommended: Tensor Parallel or Data Parallel.
- Using Tensor Parallel for a latency constraints deployment: following GPU backend design, a Megatron-LM's parallel algorithm will be used to shard the model, based on the number of NUMA nodes (e.g. TP = 2 for a two NUMA node system). With [TP feature on CPU](gh-pr:6125) merged, Tensor Parallel is supported for serving and offline inferencing. In general each NUMA node is treated as one GPU card. Below is the example script to enable Tensor Parallel = 2 for serving:
- Using Data Parallel for maximum throughput: to launch an LLM serving endpoint on each NUMA node along with one additional load balancer to dispatch the requests to those endpoints. Common solutions like [Nginx](../serving/deploying_with_nginx.md) or HAProxy are recommended. Anyscale Ray project provides the feature on LLM [serving](https://docs.ray.io/en/latest/serve/index.html). Here is the example to setup a scalable LLM serving with [Ray Serve](https://github.com/intel/llm-on-ray/blob/main/docs/setup.md).
- Using Data Parallel for maximum throughput: to launch an LLM serving endpoint on each NUMA node along with one additional load balancer to dispatch the requests to those endpoints. Common solutions like [Nginx](#nginxloadbalancer) or HAProxy are recommended. Anyscale Ray project provides the feature on LLM [serving](https://docs.ray.io/en/latest/serve/index.html). Here is the example to setup a scalable LLM serving with [Ray Serve](https://github.com/intel/llm-on-ray/blob/main/docs/setup.inc.md).
- Instruction Set Architecture (ISA): AVX512 (optional, recommended)
:::{tip}
[Intel Extension for PyTorch (IPEX)](https://github.com/intel/intel-extension-for-pytorch) extends PyTorch with up-to-date features optimizations for an extra performance boost on Intel hardware.
:::
## Set up using Python
### Pre-built wheels
### Build wheel from source
:::{include} build.inc.md
:::
:::{note}
- AVX512_BF16 is an extension ISA provides native BF16 data type conversion and vector product instructions, which brings some performance improvement compared with pure AVX512. The CPU backend build script will check the host CPU flags to determine whether to enable AVX512_BF16.
- If you want to force enable AVX512_BF16 for the cross-compilation, please set environment variable `VLLM_CPU_AVX512BF16=1` before the building.
PyTorch installed via `conda` will statically link `NCCL` library, which can cause issues when vLLM tries to use `NCCL`. See <gh-issue:8420> for more details.
:::
$# Install vLLM with CUDA 12.1.
$pip install vllm
```
In order to be performant, vLLM has to compile many cuda kernels. The compilation unfortunately introduces binary incompatibility with other CUDA versions and PyTorch versions, even for the same PyTorch version with different building configurations.
```{note}
Although we recommend using `conda` to create and manage Python environments, it is highly recommended to use `pip` to install vLLM. This is because `pip` can install `torch` with separate library packages like `NCCL`, while `conda` installs `torch` with statically linked `NCCL`. This can cause issues when vLLM tries to use `NCCL`. See <gh-issue:8420> for more details.
```
Therefore, it is recommended to install vLLM with a **fresh new** environment. If either you have a different CUDA version or you want to use an existing PyTorch installation, you need to build vLLM from source. See [below](#build-from-source) for more details.
````{note}
As of now, vLLM's binaries are compiled with CUDA 12.1 and public PyTorch release versions by default.
We also provide vLLM binaries compiled with CUDA 11.8 and public PyTorch release versions:
### Pre-built wheels
You can install vLLM using either `pip` or `uv pip`:
In order to be performant, vLLM has to compile many cuda kernels. The compilation unfortunately introduces binary incompatibility with other CUDA versions and PyTorch versions, even for the same PyTorch version with different building configurations.
As of now, vLLM's binaries are compiled with CUDA 12.1 and public PyTorch release versions by default. We also provide vLLM binaries compiled with CUDA 11.8 and public PyTorch release versions:
Therefore, it is recommended to install vLLM with a **fresh new** conda environment. If either you have a different CUDA version or you want to use an existing PyTorch installation, you need to build vLLM from source. See below for instructions.
LLM inference is a fast-evolving field, and the latest code may contain bug fixes, performance improvements, and new features that are not released yet. To allow users to try the latest code without waiting for the next release, vLLM provides wheels for Linux running on a x86 platform with CUDA 12 for every commit since `v0.5.3`. You can download and install it with the following command:
LLM inference is a fast-evolving field, and the latest code may contain bug fixes, performance improvements, and new features that are not released yet. To allow users to try the latest code without waiting for the next release, vLLM provides wheels for Linux running on a x86 platform with CUDA 12 for every commit since `v0.5.3`.
If you want to access the wheels for previous commits, you can specify the commit hash in the URL:
`--pre` is required for `pip` to consider pre-released versions.
If you want to access the wheels for previous commits (e.g. to bisect the behavior change, performance regression), due to the limitation of `pip`, you have to specify the full URL of the wheel file by embedding the commit hash in the URL:
```console
$export VLLM_COMMIT=33f460b17a54acb3b6cc0b03f4a17876cff5eafd # use full commit hash from the main branch
Note that the wheels are built with Python 3.8 ABI (see [PEP 425](https://peps.python.org/pep-0425/) for more details about ABI), so **they are compatible with Python 3.8 and later**. The version string in the wheel file name (`1.0.0.dev`) is just a placeholder to have a unified URL for the wheels. The actual versions of wheels are contained in the wheel metadata. Although we don't support Python 3.8 any more (because PyTorch 2.5 dropped support for Python 3.8), the wheels are still built with Python 3.8 ABI to keep the same wheel name as before.
Note that the wheels are built with Python 3.8 ABI (see [PEP 425](https://peps.python.org/pep-0425/) for more details about ABI), so **they are compatible with Python 3.8 and later**. The version string in the wheel file name (`1.0.0.dev`) is just a placeholder to have a unified URL for the wheels, the actual versions of wheels are contained in the wheel metadata (the wheels listed in the extra index url have correct versions). Although we don't support Python 3.8 any more (because PyTorch 2.5 dropped support for Python 3.8), the wheels are still built with Python 3.8 ABI to keep the same wheel name as before.
Another way to access the latest code is to use the docker images:
##### Install the latest code using `uv`
Another way to install the latest code is to use `uv`:
```console
$export VLLM_COMMIT=33f460b17a54acb3b6cc0b03f4a17876cff5eafd # use full commit hash from the main branch
These docker images are used for CI and testing only, and they are not intended for production use. They will be expired after several days.
If you want to access the wheels for previous commits (e.g. to bisect the behavior change, performance regression), you can specify the commit hash in the URL:
The latest code can contain bugs and may not be stable. Please use it with caution.
(build-from-source)=
```console
export VLLM_COMMIT=72d9c316d3f6ede485146fe5aabd4e61dbc59069 #use full commit hash from the main branch
The `uv` approach works for vLLM `v0.6.6` and later and offers an easy-to-remember command. A unique feature of `uv` is that packages in `--extra-index-url` have [higher priority than the default index](https://docs.astral.sh/uv/pip/compatibility/#packages-that-exist-on-multiple-indexes). If the latest public release is `v0.6.6.post1`, `uv`'s behavior allows installing a commit before `v0.6.6.post1` by specifying the `--extra-index-url`. In contrast, `pip` combines packages from `--extra-index-url` and the default index, choosing only the latest version, which makes it difficult to install a development version prior to the released version.
(python-only-build)=
### Build wheel from source
### Python-only build (without compilation)
#### Set up using Python-only build (without compilation)
If you only need to change Python code, you can build and install vLLM without compilation. Using `pip`'s [`--editable` flag](https://pip.pypa.io/en/stable/topics/local-project-installs/#editable-installs), changes you make to the code will be reflected when you run vLLM:
This will download the latest nightly wheel and use the compiled libraries from there in the install.
This will download the [latest nightly wheel](https://wheels.vllm.ai/nightly/vllm-1.0.0.dev-cp38-abi3-manylinux1_x86_64.whl) and use the compiled libraries from there in the installation.
The `VLLM_PRECOMPILED_WHEEL_LOCATION` environment variable can be used instead of `VLLM_USE_PRECOMPILED` to specify a custom path or URL to the wheel file. For example, to use the [0.6.1.post1 PyPi wheel](https://pypi.org/project/vllm/#files):
You can find more information about vLLM's wheels [above](#install-the-latest-code).
You can find more information about vLLM's wheels in <project:#install-the-latest-code>.
```{note}
:::{note}
There is a possibility that your source code may have a different commit ID compared to the latest vLLM wheel, which could potentially lead to unknown errors.
It is recommended to use the same commit ID for the source code as the vLLM wheel you have installed. Please refer to [the section above](#install-the-latest-code) for instructions on how to install a specified wheel.
```
It is recommended to use the same commit ID for the source code as the vLLM wheel you have installed. Please refer to <project:#install-the-latest-code> for instructions on how to install a specified wheel.
:::
### Full build (with compilation)
#### Full build (with compilation)
If you want to modify C++ or CUDA code, you'll need to build vLLM from source. This can take several minutes:
Building from source requires a lot of compilation. If you are building from source repeatedly, it's more efficient to cache the compilation results.
For example, you can install [ccache](https://github.com/ccache/ccache) using `conda install ccache` or `apt install ccache` .
...
...
@@ -123,9 +123,9 @@ As long as `which ccache` command can find the `ccache` binary, it will be used
[sccache](https://github.com/mozilla/sccache) works similarly to `ccache`, but has the capability to utilize caching in remote storage environments.
The following environment variables can be set to configure the vLLM `sccache` remote: `SCCACHE_BUCKET=vllm-build-sccache SCCACHE_REGION=us-west-2 SCCACHE_S3_NO_CREDENTIALS=1`. We also recommend setting `SCCACHE_IDLE_TIMEOUT=0`.
```
:::
#### Use an existing PyTorch installation
##### Use an existing PyTorch installation
There are scenarios where the PyTorch dependency cannot be easily installed via pip, e.g.:
...
...
@@ -135,32 +135,32 @@ There are scenarios where the PyTorch dependency cannot be easily installed via
To build vLLM using an existing PyTorch installation:
Currently, before starting the build process, vLLM fetches cutlass code from GitHub. However, there may be scenarios where you want to use a local version of cutlass instead.
To achieve this, you can set the environment variable VLLM_CUTLASS_SRC_DIR to point to your local cutlass directory.
To avoid your system being overloaded, you can limit the number of compilation jobs
to be run simultaneously, via the environment variable `MAX_JOBS`. For example:
```console
$export MAX_JOBS=6
$pip install-e .
export MAX_JOBS=6
pip install -e .
```
This is especially useful when you are building on less powerful machines. For example, when you use WSL it only [assigns 50% of the total memory by default](https://learn.microsoft.com/en-us/windows/wsl/wsl-config#main-wsl-settings), so using `export MAX_JOBS=1` can avoid compiling multiple files simultaneously and running out of memory.
...
...
@@ -169,31 +169,56 @@ A side effect is a much slower build process.
Additionally, if you have trouble building vLLM, we recommend using the NVIDIA PyTorch Docker image.
```console
$# Use `--ipc=host` to make sure the shared memory is large enough.
$docker run --gpus all -it--rm--ipc=host nvcr.io/nvidia/pytorch:23.10-py3
#Use `--ipc=host` to make sure the shared memory is large enough.
docker run --gpus all -it --rm --ipc=host nvcr.io/nvidia/pytorch:23.10-py3
```
If you don't want to use docker, it is recommended to have a full installation of CUDA Toolkit. You can download and install it from [the official website](https://developer.nvidia.com/cuda-toolkit-archive). After installation, set the environment variable `CUDA_HOME` to the installation path of CUDA Toolkit, and make sure that the `nvcc` compiler is in your `PATH`, e.g.:
```console
$export CUDA_HOME=/usr/local/cuda
$export PATH="${CUDA_HOME}/bin:$PATH"
export CUDA_HOME=/usr/local/cuda
export PATH="${CUDA_HOME}/bin:$PATH"
```
Here is a sanity check to verify that the CUDA Toolkit is correctly installed:
```console
$nvcc --version# verify that nvcc is in your PATH
$${CUDA_HOME}/bin/nvcc --version# verify that nvcc is in your CUDA_HOME
nvcc --version #verify that nvcc is in your PATH
${CUDA_HOME}/bin/nvcc --version# verify that nvcc is in your CUDA_HOME
```
### Unsupported OS build
#### Unsupported OS build
vLLM can fully run only on Linux but for development purposes, you can still build it on other systems (for example, macOS), allowing for imports and a more convenient development environment. The binaries will not be compiled and won't work on non-Linux systems.
Simply disable the `VLLM_TARGET_DEVICE` environment variable before installing:
```console
$export VLLM_TARGET_DEVICE=empty
$pip install-e .
export VLLM_TARGET_DEVICE=empty
pip install -e .
```
## Set up using Docker
### Pre-built images
See <project:#deployment-docker-pre-built-image> for instructions on using the official Docker image.
Another way to access the latest code is to use the docker images:
```console
export VLLM_COMMIT=33f460b17a54acb3b6cc0b03f4a17876cff5eafd #use full commit hash from the main branch
For installing PyTorch, you can start from a fresh docker image, e.g, `rocm/pytorch:rocm6.2_ubuntu20.04_py3.9_pytorch_release_2.3.0`, `rocm/pytorch-nightly`.
Alternatively, you can install PyTorch using PyTorch wheels. You can check PyTorch installation guide in PyTorch [Getting Started](https://pytorch.org/get-started/locally/)
1. Install [Triton flash attention for ROCm](https://github.com/ROCm/triton)
Install ROCm's Triton flash attention (the default triton-mlir branch) following the instructions from [ROCm/triton](https://github.com/ROCm/triton/blob/triton-mlir/README.md)
```console
python3 -m pip install ninja cmake wheel pybind11
pip uninstall -y triton
git clone https://github.com/OpenAI/triton.git
cd triton
git checkout e192dba
cd python
pip3 install .
cd ../..
```
:::{note}
If you see HTTP issue related to downloading packages during building triton, please try again as the HTTP error is intermittent.
:::
2. Optionally, if you choose to use CK flash attention, you can install [flash attention for ROCm](https://github.com/ROCm/flash-attention/tree/ck_tile)
Install ROCm's flash attention (v2.5.9.post1) following the instructions from [ROCm/flash-attention](https://github.com/ROCm/flash-attention/tree/ck_tile#amd-gpurocm-support)
Alternatively, wheels intended for vLLM use can be accessed under the releases.
For example, for ROCm 6.2, suppose your gfx arch is `gfx90a`. To get your gfx architecture, run `rocminfo |grep gfx`.
## Option 1: Build from source with docker (recommended)
# Build vLLM for MI210/MI250/MI300.
$ export PYTORCH_ROCM_ARCH="gfx90a;gfx942"
$ python3 setup.py develop
```
You can build and install vLLM from source.
This may take 5-10 minutes. Currently, `pip install .` does not work for ROCm installation.
<!--- pyml disable-num-lines 5 ul-indent-->
:::{tip}
- Triton flash attention is used by default. For benchmarking purposes, it is recommended to run a warm up step before collecting perf numbers.
- Triton flash attention does not currently support sliding window attention. If using half precision, please use CK flash-attention for sliding window support.
- To use CK flash-attention or PyTorch naive attention, please use this flag `export VLLM_USE_TRITON_FLASH_ATTN=0` to turn off triton flash attention.
- The ROCm version of PyTorch, ideally, should match the ROCm driver version.
:::
:::{tip}
- For MI300x (gfx942) users, to achieve optimal performance, please refer to [MI300x tuning guide](https://rocm.docs.amd.com/en/latest/how-to/tuning-guides/mi300x/index.html) for performance optimization and tuning tips on system and workflow level.
For vLLM, please refer to [vLLM performance optimization](https://rocm.docs.amd.com/en/latest/how-to/tuning-guides/mi300x/workload.html#vllm-performance-optimization).
:::
## Set up using Docker
### Pre-built images
The [AMD Infinity hub for vLLM](https://hub.docker.com/r/rocm/vllm/tags) offers a prebuilt, optimized
docker image designed for validating inference performance on the AMD Instinct™ MI300X accelerator.
:::{tip}
Please check [LLM inference performance validation on AMD Instinct MI300X](https://rocm.docs.amd.com/en/latest/how-to/performance-validation/mi300x/vllm-benchmark.html)
for instructions on how to use this prebuilt docker image.
:::
### Build image from source
Building the Docker image from source is the recommended way to use vLLM with ROCm.
First, build a docker image from <gh-file:Dockerfile.rocm> and launch a docker container from the image.
It is important that the user kicks off the docker build using buildkit. Either the user put DOCKER_BUILDKIT=1 as environment variable when calling docker build command, or the user needs to setup buildkit in the docker daemon configuration /etc/docker/daemon.json as follows and restart the daemon:
...
...
@@ -36,30 +134,29 @@ It is important that the user kicks off the docker build using buildkit. Either
<gh-file:Dockerfile.rocm> uses ROCm 6.2 by default, but also supports ROCm 5.7, 6.0 and 6.1 in older vLLM branches.
It provides flexibility to customize the build of docker image using the following arguments:
-`BASE_IMAGE`: specifies the base image used when running `docker build`, specifically the PyTorch on ROCm base image.
-`BUILD_FA`: specifies whether to build CK flash-attention. The default is 1. For [Radeon RX 7900 series (gfx1100)](https://rocm.docs.amd.com/projects/radeon/en/latest/index.html), this should be set to 0 before flash-attention supports this target.
-`FX_GFX_ARCHS`: specifies the GFX architecture that is used to build CK flash-attention, for example, `gfx90a;gfx942` for MI200 and MI300. The default is `gfx90a;gfx942`
-`FA_BRANCH`: specifies the branch used to build the CK flash-attention in [ROCm's flash-attention repo](https://github.com/ROCmSoftwarePlatform/flash-attention). The default is `ae7928c`
-`BUILD_TRITON`: specifies whether to build triton flash-attention. The default value is 1.
-`BASE_IMAGE`: specifies the base image used when running `docker build`. The default value `rocm/vllm-dev:base` is an image published and maintained by AMD. It is being built using <gh-file:Dockerfile.rocm_base>
-`USE_CYTHON`: An option to run cython compilation on a subset of python files upon docker build
-`BUILD_RPD`: Include RocmProfileData profiling tool in the image
-`ARG_PYTORCH_ROCM_ARCH`: Allows to override the gfx architecture values from the base docker image
Their values can be passed in when running `docker build` with `--build-arg` options.
To build vllm on ROCm 6.2 for MI200 and MI300 series, you can use the default:
For installing PyTorch, you can start from a fresh docker image, e.g, `rocm/pytorch:rocm6.2_ubuntu20.04_py3.9_pytorch_release_2.3.0`, `rocm/pytorch-nightly`.
Alternatively, you can install PyTorch using PyTorch wheels. You can check PyTorch installation guide in PyTorch [Getting Started](https://pytorch.org/get-started/locally/)
1. Install [Triton flash attention for ROCm](https://github.com/ROCm/triton)
Install ROCm's Triton flash attention (the default triton-mlir branch) following the instructions from [ROCm/triton](https://github.com/ROCm/triton/blob/triton-mlir/README.md)
- If you see HTTP issue related to downloading packages during building triton, please try again as the HTTP error is intermittent.
```
2. Optionally, if you choose to use CK flash attention, you can install [flash attention for ROCm](https://github.com/ROCm/flash-attention/tree/ck_tile)
Install ROCm's flash attention (v2.5.9.post1) following the instructions from [ROCm/flash-attention](https://github.com/ROCm/flash-attention/tree/ck_tile#amd-gpurocm-support)
Alternatively, wheels intended for vLLM use can be accessed under the releases.
For example, for ROCm 6.2, suppose your gfx arch is `gfx90a`. To get your gfx architecture, run `rocminfo |grep gfx`.
This may take 5-10 minutes. Currently, {code}`pip install .` does not work for ROCm installation.
```{tip}
- Triton flash attention is used by default. For benchmarking purposes, it is recommended to run a warm up step before collecting perf numbers.
- Triton flash attention does not currently support sliding window attention. If using half precision, please use CK flash-attention for sliding window support.
- To use CK flash-attention or PyTorch naive attention, please use this flag `export VLLM_USE_TRITON_FLASH_ATTN=0` to turn off triton flash attention.
- The ROCm version of PyTorch, ideally, should match the ROCm driver version.
```
```{tip}
- For MI300x (gfx942) users, to achieve optimal performance, please refer to [MI300x tuning guide](https://rocm.docs.amd.com/en/latest/how-to/tuning-guides/mi300x/index.html) for performance optimization and tuning tips on system and workflow level.
For vLLM, please refer to [vLLM performance optimization](https://rocm.docs.amd.com/en/latest/how-to/tuning-guides/mi300x/workload.html#vllm-performance-optimization).
```
See <project:#feature-x-hardware> compatibility matrix for feature support information.
XPU platform supports tensor-parallel inference/serving and also supports pipeline parallel as a beta feature for online serving. We requires Ray as the distributed runtime backend. For example, a reference execution likes following:
```console
$python -m vllm.entrypoints.openai.api_server \
$ --model=facebook/opt-13b \
$ --dtype=bfloat16 \
$ --device=xpu \
$ --max_model_len=1024 \
$ --distributed-executor-backend=ray \
$ --pipeline-parallel-size=2 \
$ -tp=8
python -m vllm.entrypoints.openai.api_server \
--model=facebook/opt-13b \
--dtype=bfloat16 \
--device=xpu \
--max_model_len=1024 \
--distributed-executor-backend=ray \
--pipeline-parallel-size=2 \
-tp=8
```
By default, a ray instance will be launched automatically if no existing one is detected in system, with `num-gpus` equals to `parallel_config.world_size`. We recommend properly starting a ray cluster before execution, referring to the <gh-file:examples/run_cluster.sh> helper script.
By default, a ray instance will be launched automatically if no existing one is detected in system, with `num-gpus` equals to `parallel_config.world_size`. We recommend properly starting a ray cluster before execution, referring to the <gh-file:examples/online_serving/run_cluster.sh> helper script.