diff mbox series

[v2,1/2] doc: add note about CPU 0

Message ID 20240731043846.78174-1-stephen@networkplumber.org (mailing list archive)
State New
Delegated to: Thomas Monjalon
Headers
Series [v2,1/2] doc: add note about CPU 0 |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Stephen Hemminger July 31, 2024, 4:38 a.m. UTC 
On Linux (and probably BSD), CPU 0 can not be fully isolated
because it receives timer interrupts and is used for other
kernel related functions. The DPDK documentation should
be updated to tell users to avoid polling on that CPU.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 doc/guides/linux_gsg/enable_func.rst | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox series

Patch

diff --git a/doc/guides/linux_gsg/enable_func.rst b/doc/guides/linux_gsg/enable_func.rst
index 5511640cb8..9f4391456a 100644
--- a/doc/guides/linux_gsg/enable_func.rst
+++ b/doc/guides/linux_gsg/enable_func.rst
@@ -131,6 +131,11 @@  from running on those cores, it is possible to use
 the Linux kernel parameters ``isolcpus``, ``nohz_full``, ``irqaffinity``
 to isolate them from the general Linux scheduler tasks.
 
+.. note::
+
+   It is not recommended to use CPU core 0 for DPDK polling applications
+   because it can not be completely isolated from other system and kernel activity.
+
 For example, if a given CPU has 0-7 cores
 and DPDK applications are to run on logical cores 2, 4 and 6,
 the following should be added to the kernel parameter list: