[docs] add SYS_NICE cap & `security-opt` for docker/k8s (#24017)

Signed-off-by: Peter Pan <Peter.Pan@daocloud.io>
Signed-off-by: Peter Pan <peter.pan@daocloud.io>
Co-authored-by: Li, Jiang <bigpyj64@gmail.com>
Co-authored-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

docs/getting_started/installation/cpu.md

@@ -194,3 +194,35 @@ vLLM CPU supports data parallel (DP), tensor parallel (TP) and pipeline parallel
 - Both of them require `amx` CPU flag.
     - `VLLM_CPU_MOE_PREPACK` can provides better performance for MoE models
     - `VLLM_CPU_SGL_KERNEL` can provides better performance for MoE models and small-batch scenarios.
+
+### Why do I see `get_mempolicy: Operation not permitted` when running in Docker?
+
+In some container environments (like Docker), NUMA-related syscalls used by vLLM (e.g., `get_mempolicy`, `migrate_pages`) are blocked/denied in the runtime's default seccomp/capabilities settings. This may lead to warnings like `get_mempolicy: Operation not permitted`. Functionality is not affected, but NUMA memory binding/migration optimizations may not take effect and performance can be suboptimal.
+
+To enable these optimizations inside Docker with the least privilege, you can follow below tips:
+
+```bash
+docker run ... --cap-add SYS_NICE --security-opt seccomp=unconfined  ...
+
+# 1) `--cap-add SYS_NICE` is to address `get_mempolicy` EPERM issue.
+
+# 2) `--security-opt seccomp=unconfined` is to enable `migrate_pages` for `numa_migrate_pages()`.
+# Actually, `seccomp=unconfined` bypasses the seccomp for container,
+# if it's unacceptable, you can customize your own seccomp profile,
+# based on docker/runtime default.json and add `migrate_pages` to `SCMP_ACT_ALLOW` list.
+
+# reference : https://docs.docker.com/engine/security/seccomp/
+```
+
+Alternatively, running with `--privileged=true` also works but is broader and not generally recommended.
+
+In K8S, the following configuration can be added to workload yaml to achieve the same effect as above:
+
+```yaml
+securityContext:
+  seccompProfile:
+    type: Unconfined
+  capabilities:
+    add:
+    - SYS_NICE
+```

docs/getting_started/installation/cpu/arm.inc.md

@@ -48,6 +48,10 @@ docker run --rm \
             --dtype=bfloat16 \
             other vLLM OpenAI server arguments
 ```
+
+!!! tip
+    An alternative of `--privileged=true` is `--cap-add SYS_NICE --security-opt seccomp=unconfined`.
+
 # --8<-- [end:build-image-from-source]
 # --8<-- [start:extra-information]
 # --8<-- [end:extra-information]

docs/getting_started/installation/cpu/s390x.inc.md

@@ -89,6 +89,9 @@ docker run --rm \
     other vLLM OpenAI server arguments
 ```
 
+!!! tip
+    An alternative of `--privileged true` is `--cap-add SYS_NICE --security-opt seccomp=unconfined`.
+
 # --8<-- [end:build-image-from-source]
 # --8<-- [start:extra-information]
 # --8<-- [end:extra-information]

docs/getting_started/installation/cpu/x86.inc.md

@@ -44,6 +44,7 @@ docker build -f docker/Dockerfile.cpu \
 # Launching OpenAI server
 docker run --rm \
             --security-opt seccomp=unconfined \
+            --cap-add SYS_NICE \
             --shm-size=4g \
             -p 8000:8000 \
             -e VLLM_CPU_KVCACHE_SPACE=<KV cache space> \