[PATCH] doc: enhance the global log level documentation

[David Marchand <david.marchand@redhat.com>]

The current documentation is non intuitive in that the global log level
can be understood as being a single knob controlling all components
logs.
On the contrary, all the global log level is for is to reduce verbosity
globally.

Remove examples of setting --log-level=8|debug, which is a noop.

Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 doc/guides/cryptodevs/octeontx.rst |  2 +-
 doc/guides/prog_guide/log_lib.rst  | 10 ++++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/doc/guides/cryptodevs/octeontx.rst b/doc/guides/cryptodevs/octeontx.rst
index a39f3f3d02..97e13514f3 100644
--- a/doc/guides/cryptodevs/octeontx.rst
+++ b/doc/guides/cryptodevs/octeontx.rst
@@ -114,7 +114,7 @@ OCTEON TX crypto PMD.
 
 .. code-block:: console
 
-        ./build/ipsec-secgw --log-level=8 -c 0xff -- -P -p 0x3 -u 0x2 --config
+        ./build/ipsec-secgw -c 0xff -- -P -p 0x3 -u 0x2 --config
         "(1,0,0),(0,0,0)" -f ep1.cfg
 
 Testing
diff --git a/doc/guides/prog_guide/log_lib.rst b/doc/guides/prog_guide/log_lib.rst
index ff9d1b54a2..965b7e9961 100644
--- a/doc/guides/prog_guide/log_lib.rst
+++ b/doc/guides/prog_guide/log_lib.rst
@@ -32,18 +32,20 @@ or by the user passing the ``--log-level`` parameter to the EAL via the applicat
 Setting Global Log Level
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
-To adjust the global log level for an application,
-just pass a numeric level or a level name to the ``--log-level`` EAL parameter.
+By default, the global log level is set to ``RTE_LOG_DEBUG``.
+
+To reduce the verbosity of an application globally,
+adjust the global log level by passing a numeric level or a level name to the ``--log-level`` EAL parameter.
 For example::
 
 	/path/to/app --log-level=error
 
-	/path/to/app --log-level=debug
-
 	/path/to/app --log-level=5   # warning
 
 Within an application, the log level can be similarly set using the ``rte_log_set_global_level`` API.
 
+For setting per component log levels, see below.
+
 Setting Log Level for a Component
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-- 
2.45.2