doc: improve event core description in vDPA mlx5

Message ID 20221113092137.1252803-1-matan@nvidia.com (mailing list archive)
State Accepted, archived
Delegated to: Maxime Coquelin
Headers
Series doc: improve event core description in vDPA mlx5 |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/iol-mellanox-Performance success Performance Testing PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-intel-Functional success Functional Testing PASS
ci/iol-aarch64-unit-testing success Testing PASS
ci/iol-x86_64-compile-testing success Testing PASS
ci/iol-aarch64-compile-testing success Testing PASS
ci/iol-x86_64-unit-testing success Testing PASS
ci/github-robot: build success github build: passed
ci/Intel-compilation success Compilation OK
ci/intel-Testing success Testing PASS

Commit Message

Matan Azrad Nov. 13, 2022, 9:21 a.m. UTC
  The event core is mlx5 vDPA driver devarg that selects the CPU core for
the internal timer thread used to manage data-path events into the
driver.

Emphasize that this CPU should be isolated for vDPA mlx5 devices only in
order to save the performance and latency of the device.

Signed-off-by: Matan Azrad <matan@nvidia.com>
---
 doc/guides/vdpadevs/mlx5.rst | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)
  

Comments

Chenbo Xia Nov. 21, 2022, 1:38 a.m. UTC | #1
> -----Original Message-----
> From: Matan Azrad <matan@nvidia.com>
> Sent: Sunday, November 13, 2022 5:22 PM
> To: Maxime Coquelin <maxime.coquelin@redhat.com>
> Cc: dev@dpdk.org
> Subject: [PATCH] doc: improve event core description in vDPA mlx5
> 
> The event core is mlx5 vDPA driver devarg that selects the CPU core for
> the internal timer thread used to manage data-path events into the
> driver.
> 
> Emphasize that this CPU should be isolated for vDPA mlx5 devices only in
> order to save the performance and latency of the device.
> 
> Signed-off-by: Matan Azrad <matan@nvidia.com>
> ---
>  doc/guides/vdpadevs/mlx5.rst | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/doc/guides/vdpadevs/mlx5.rst b/doc/guides/vdpadevs/mlx5.rst
> index 9767fbe42d..3b5ce6df38 100644
> --- a/doc/guides/vdpadevs/mlx5.rst
> +++ b/doc/guides/vdpadevs/mlx5.rst
> @@ -86,8 +86,13 @@ for an additional list of options shared with other
> mlx5 drivers.
> 
>  - ``event_core`` parameter [int]
> 
> -  CPU core number to set polling thread affinity to, default to control
> plane
> -  cpu.
> +  The CPU core number of the timer thread, default: EAL main lcore.
> +
> +.. note::
> +
> +   This core can be shared among different mlx5 vDPA devices as
> `event_core` but
> +   using it also for other tasks may affect the performance and the
> latency of the
> +   mlx5 vDPA devices.
> 
>  - ``max_conf_threads`` parameter [int]
> 
> --
> 2.25.1

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
  
Thomas Monjalon Nov. 21, 2022, 7:50 p.m. UTC | #2
> > The event core is mlx5 vDPA driver devarg that selects the CPU core for
> > the internal timer thread used to manage data-path events into the
> > driver.
> > 
> > Emphasize that this CPU should be isolated for vDPA mlx5 devices only in
> > order to save the performance and latency of the device.
> > 
> > Signed-off-by: Matan Azrad <matan@nvidia.com>
> 
> Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>

Applied, thanks.
  

Patch

diff --git a/doc/guides/vdpadevs/mlx5.rst b/doc/guides/vdpadevs/mlx5.rst
index 9767fbe42d..3b5ce6df38 100644
--- a/doc/guides/vdpadevs/mlx5.rst
+++ b/doc/guides/vdpadevs/mlx5.rst
@@ -86,8 +86,13 @@  for an additional list of options shared with other mlx5 drivers.
 
 - ``event_core`` parameter [int]
 
-  CPU core number to set polling thread affinity to, default to control plane
-  cpu.
+  The CPU core number of the timer thread, default: EAL main lcore.
+
+.. note::
+
+   This core can be shared among different mlx5 vDPA devices as `event_core` but
+   using it also for other tasks may affect the performance and the latency of the
+   mlx5 vDPA devices.
 
 - ``max_conf_threads`` parameter [int]