957804df56
### What this PR does / why we need it?
1. Following https://github.com/vllm-project/vllm/pull/32322, use the
`memory_profiling` context manager from vllm for profiling.
2. Fix wrong non-torch memory value recorded during profiling, which is
not its peak during inference.
---
**More details about point 2:**
After profling, the non-torch memory value we recorded is lower than
that in real inference. This is mainly because of the different memory
management behaviour between `torch.cuda.empty_cache()` and
`torch.npu.empty_cache()`.
With regard to `torch.cuda.empty_cache()`, it only recycle the unused
memory in pytorch memory pool (i.e., memory managed by pytorch caching
allocator), **with no affect to non-torch memory**. However, as for
`torch.npu.empty_cache()`, it has a totally different memory management
mechanism, i.e., it may call `aclrtSynchronize` and **enable Ascend
runtime to free up non-torch memory**.
Thus, the non-torch memory value we recorded after
`torch.npu.empty_cache()` is much lower than its peak during profling.
Resolution:
We record the peak non-torch memory value
(`non_torch_memory_before_empty_cache`) after profiling, but before
`torch.npu.empty_cache()`. Then, we add the diff
(`non_torch_memory_cleared_by_empty_cache =
non_torch_memory_before_empty_cache - self.non_torch_memory`) to
non-torch memory when calculating available KV cache memory, which will
lead to less KV cache memory (i.e., it's safer to avoid OOM issues).
---
> [!NOTE]
> This PR needs to wait for main2main aligning to latest vllm commit
before merging.
### Does this PR introduce _any_ user-facing change?
no.
### How was this patch tested?
Before this PR, the non-torch memory we used to calculate available KV
cache memory is **0.90 G**, whereas its peak during real inference is
**1.08 G**, diff: **182.00 M**.
After this PR, we add this diff to non-torch memory after profiling and
thus make the profiling results more accurate.
- vLLM version: v0.15.0
- vLLM main:
d7e17aaacd
---------
Signed-off-by: shen-shanshan <467638484@qq.com>
vLLM Ascend Plugin
| About Ascend | Documentation | #SIG-Ascend | Users Forum | Weekly Meeting |
English | 中文
Latest News 🔥
- [2026/02] We released the new official version v0.13.0! Please follow the official guide to start using vLLM Ascend Plugin on Ascend.
- [2025/12] We released the new official version v0.11.0! Please follow the official guide to start using vLLM Ascend Plugin on Ascend.
- [2025/09] We released the new official version v0.9.1! Please follow the official guide to start deploying large-scale Expert Parallelism (EP) on Ascend.
- [2025/08] We hosted the vLLM Beijing Meetup with vLLM and Tencent! Please find the meetup slides here.
- [2025/06] User stories page is now live! It kicks off with LLaMA-Factory/verl/TRL/GPUStack to demonstrate how vLLM Ascend assists Ascend users in enhancing their experience across fine-tuning, evaluation, reinforcement learning (RL), and deployment scenarios.
- [2025/06] Contributors page is now live! All contributions deserve to be recorded, thanks for all contributors.
- [2025/05] We've released the first official version v0.7.3! We collaborated with the vLLM community to publish a blog post sharing our practice: Introducing vLLM Hardware Plugin, Best Practice from Ascend NPU.
- [2025/03] We hosted the vLLM Beijing Meetup with vLLM team! Please find the meetup slides here.
- [2025/02] vLLM community officially created vllm-project/vllm-ascend repo for running vLLM seamlessly on the Ascend NPU.
- [2024/12] We are working with the vLLM community to support [RFC]: Hardware pluggable.
Overview
vLLM Ascend (vllm-ascend) is a community maintained hardware plugin for running vLLM seamlessly on the Ascend NPU.
It is the recommended approach for supporting the Ascend backend within the vLLM community. It adheres to the principles outlined in the [RFC]: Hardware pluggable, providing a hardware-pluggable interface that decouples the integration of the Ascend NPU with vLLM.
By using vLLM Ascend plugin, popular open-source models, including Transformer-like, Mixture-of-Experts (MoE), Embedding, Multi-modal LLMs can run seamlessly on the Ascend NPU.
Prerequisites
- Hardware: Atlas 800I A2 Inference series, Atlas A2 Training series, Atlas 800I A3 Inference series, Atlas A3 Training series, Atlas 300I Duo (Experimental)
- OS: Linux
- Software:
- Python >= 3.10, < 3.12
- CANN == 8.5.0 (Ascend HDK version refers to here)
- PyTorch == 2.9.0, torch-npu == 2.9.0
- vLLM (the same version as vllm-ascend)
Getting Started
Please use the following recommended versions to get started quickly:
| Version | Release type | Doc |
|---|---|---|
| v0.14.0rc1 | Latest release candidate | See QuickStart and Installation for more details |
| v0.13.0 | Latest stable version | See QuickStart and Installation for more details |
Contributing
See CONTRIBUTING for more details, which is a step-by-step guide to help you set up the development environment, build and test.
We welcome and value any contributions and collaborations:
- Please let us know if you encounter a bug by filing an issue
- Please use User forum for usage questions and help.
Branch
vllm-ascend has a main branch and a dev branch.
- main: main branch, corresponds to the vLLM main branch, and is continuously monitored for quality through Ascend CI.
- releases/vX.Y.Z: development branch, created alongside new releases of vLLM. For example,
releases/v0.13.0is the dev branch for vLLMv0.13.0version.
Below are the maintained branches:
| Branch | Status | Note |
|---|---|---|
| main | Maintained | CI commitment for vLLM main branch and vLLM v0.13.0 tag |
| v0.7.1-dev | Unmaintained | Only doc fixes are allowed |
| v0.7.3-dev | Maintained | CI commitment for vLLM 0.7.3 version, only bug fixes are allowed, and no new release tags anymore. |
| v0.9.1-dev | Maintained | CI commitment for vLLM 0.9.1 version |
| v0.11.0-dev | Maintained | CI commitment for vLLM 0.11.0 version |
| releases/v0.13.0 | Maintained | CI commitment for vLLM 0.13.0 version |
| rfc/feature-name | Maintained | Feature branches for collaboration |
Please refer to Versioning policy for more details.
Weekly Meeting
- vLLM Ascend Weekly Meeting: https://tinyurl.com/vllm-ascend-meeting
- Wednesday, 15:00 - 16:00 (UTC+8, Convert to your timezone)
License
Apache License 2.0, as found in the LICENSE file.