[v2,3/3] doc: add notes on overriding extra config values

Message ID 20200903144942.671870-4-bruce.richardson@intel.com (mailing list archive)
State Rejected, archived
Delegated to: Thomas Monjalon
Headers
Series Allow overriding of build-time constants |

Checks

Context Check Description
ci/iol-broadcom-Functional success Functional Testing PASS
ci/iol-broadcom-Performance success Performance Testing PASS
ci/iol-intel-Functional success Functional Testing PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-testing success Testing PASS
ci/iol-mellanox-Performance success Performance Testing PASS
ci/travis-robot success Travis build: passed
ci/Intel-compilation success Compilation OK
ci/checkpatch success coding style OK

Commit Message

Bruce Richardson Sept. 3, 2020, 2:49 p.m. UTC
  Since it's possible to tweak the DPDK build a little further using CFLAGS,
we note that in the documentation.

Suggested-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 doc/guides/linux_gsg/build_dpdk.rst       | 8 ++++++++
 doc/guides/prog_guide/build-sdk-meson.rst | 8 ++++++++
 2 files changed, 16 insertions(+)
  

Comments

Hemant Agrawal Sept. 3, 2020, 3:43 p.m. UTC | #1
Acked-by: Hemant Agrawal <Hemant.agrawal@nxp.com>
  

Patch

diff --git a/doc/guides/linux_gsg/build_dpdk.rst b/doc/guides/linux_gsg/build_dpdk.rst
index c536e354e..9c242069e 100644
--- a/doc/guides/linux_gsg/build_dpdk.rst
+++ b/doc/guides/linux_gsg/build_dpdk.rst
@@ -117,6 +117,14 @@  dependencies are met on the current system are built.
 When `-Dexamples=all` is set as a meson option, meson will check each example application to see if it can be built,
 and add all which can be built to the list of tasks in the ninja build configuration file.
 
+.. note::
+
+    A number of buildtime constants are present in DPDK, listed in file ``config/rte_config.h``.
+    While these should not normally need to be changed,
+    they can be overridden by setting the new value of the constant in the ``CFLAGS`` environment variable,
+    or via ``c_args`` meson parameter.
+    For example: ``meson configure -Dc_args="-DRTE_PKTMBUF_HEADROOM=256"``
+
 Building Applications Using Installed DPDK
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/doc/guides/prog_guide/build-sdk-meson.rst b/doc/guides/prog_guide/build-sdk-meson.rst
index 44d1cafdf..3838871a3 100644
--- a/doc/guides/prog_guide/build-sdk-meson.rst
+++ b/doc/guides/prog_guide/build-sdk-meson.rst
@@ -68,6 +68,14 @@  built into meson, while others, such as ``max_lcores``, or the list of
 examples to build, are DPDK-specific. To have a list of all options
 available run ``meson configure`` in the build directory.
 
+.. note::
+
+    A number of buildtime constants are present in DPDK, listed in file ``config/rte_config.h``.
+    While these should not normally need to be changed,
+    they can be overridden by setting the new value of the constant in the ``CFLAGS`` environment variable,
+    or via ``c_args`` meson parameter.
+    For example: ``meson configure -Dc_args="-DRTE_PKTMBUF_HEADROOM=256"``
+
 Examples of adjusting the defaults when doing initial meson configuration.
 Project-specific options are passed used -Doption=value::