docs: minor improvement to core-pinning documentation

Type: docs
Change-Id: I05691e77855832ebbd9a3f9ee7de8a4edc1d75fe
Signed-off-by: Hadi Rayan Al-Sandid <[email protected]>

diff --git a/docs/configuration/reference.rst b/docs/configuration/reference.rst
index 9378ce5..e2016b1 100644 (file)
--- a/docs/configuration/reference.rst
+++ b/docs/configuration/reference.rst
@@ -469,12 +469,16 @@ CPU cores while skipping "skip-cores" CPU core(s) and main thread's CPU core
 relative
 ^^^^^^^^^
 
-Apply thread pinning configuration with respect to the available logical cores
-in the current control group CPU set.
+Apply thread pinning configuration with respect to the logical cores available
+to the VPP process, rather than all logical cores present on the host machine.
+
 By default, VPP applies the thread pinning configuration with respect to the
-available logical cores on host (e.g. '/sys/devices/system/cpu/online'). With
-the 'relative' keyword, the thread pinning configuration is applied with respect
-to the available logical cores (obtained with sched_getaffinity).
+available logical cores on host (e.g. '/sys/devices/system/cpu/online'), but with
+the 'relative' keyword, we apply the thread pinning configuration with respect
+to logical cores available to the VPP process (obtained with sched_getaffinity).
+
+This parameter can be useful when running VPP in an environment with restricted access
+to host CPU resources (e.g. running in a container, or using taskset).
 
 .. code-block:: console
 

diff --git a/docs/spelling_wordlist.txt b/docs/spelling_wordlist.txt
index 51b929e..cd9d750 100644 (file)
--- a/docs/spelling_wordlist.txt
+++ b/docs/spelling_wordlist.txt
@@ -1135,6 +1135,7 @@ Tahr
 tapcli
 tcp
 tcpcontrolbits
+taskset
 te
 teardown
 tearDown

diff --git a/src/vpp/conf/startup.conf b/src/vpp/conf/startup.conf
index 8e7aebd..938869d 100644 (file)
--- a/src/vpp/conf/startup.conf
+++ b/src/vpp/conf/startup.conf
@@ -81,6 +81,10 @@ cpu {
        ## and main thread's CPU core
        # workers 2
 
+       ## Apply thread pinning configuration with respect to the logical cores available
+       ## to VPP at launch, rather than all logical cores present on the host machine
+       # relative
+
        ## Set scheduling policy and priority of main and worker threads
 
        ## Scheduling policy options are: other (SCHED_OTHER), batch (SCHED_BATCH)