[Doc] Add documentation for vLLM continuous benchmarking and profiling (#25819)

Signed-off-by: Naman Lalit <nl2688@nyu.edu>

docs/contributing/benchmarks.md

@@ -823,6 +823,30 @@ The latest performance results are hosted on the public [vLLM Performance Dashbo
 
 More information on the performance benchmarks and their parameters can be found in [Benchmark README](https://github.com/intel-ai-tce/vllm/blob/more_cpu_models/.buildkite/nightly-benchmarks/README.md) and [performance benchmark description](gh-file:.buildkite/nightly-benchmarks/performance-benchmarks-descriptions.md).
 
+### Continuous Benchmarking
+
+The continuous benchmarking provides automated performance monitoring for vLLM across different models and GPU devices. This helps track vLLM's performance characteristics over time and identify any performance regressions or improvements.
+
+#### How It Works
+
+The continuous benchmarking is triggered via a [GitHub workflow CI](https://github.com/pytorch/pytorch-integration-testing/actions/workflows/vllm-benchmark.yml) in the PyTorch infrastructure repository, which runs automatically every 4 hours. The workflow executes three types of performance tests:
+
+- **Serving tests**: Measure request handling and API performance
+- **Throughput tests**: Evaluate token generation rates
+- **Latency tests**: Assess response time characteristics
+
+#### Benchmark Configuration
+
+The benchmarking currently runs on a predefined set of models configured in the [vllm-benchmarks directory](https://github.com/pytorch/pytorch-integration-testing/tree/main/vllm-benchmarks/benchmarks). To add new models for benchmarking:
+
+1. Navigate to the appropriate GPU directory in the benchmarks configuration
+2. Add your model specifications to the corresponding configuration files
+3. The new models will be included in the next scheduled benchmark run
+
+#### Viewing Results
+
+All continuous benchmarking results are automatically published to the public [vLLM Performance Dashboard](https://hud.pytorch.org/benchmark/llms?repoName=vllm-project%2Fvllm).
+
 [](){ #nightly-benchmarks }
 
 ## Nightly Benchmarks