lttng-ust(3): reword and fix style of `LTTNG_UST_ALLOW_BLOCKING` variable

[lttng-ust.git] / doc / man / lttng-ust.3.txt

diff --git a/doc/man/lttng-ust.3.txt b/doc/man/lttng-ust.3.txt
index 28d66f2565b3af2b9e54f01cbb660220c6002d3e..5c9c9f5de2167addcb4427aaedf5a581c456b754 100644 (file)
--- a/doc/man/lttng-ust.3.txt
+++ b/doc/man/lttng-ust.3.txt
@@ -1293,11 +1293,15 @@ are located in a specific directory under `$LTTNG_HOME` (or `$HOME` if
 `$LTTNG_HOME` is not set).
 
 `LTTNG_UST_ALLOW_BLOCKING`::
-    If set, allow application to retry event tracing when there's
+    If set, allow the application to retry event tracing when there's
     no space left for the event record in the sub-buffer, therefore
     effectively blocking the application until space is made available
-    or timeout is reached. This only has effect on channels with
-    `blocking-timeout` set.
+    or the configured timeout is reached.
++
+To allow an application to block during tracing, you also need to
+specify a blocking timeout when you create a channel with the
+nloption:--blocking-timeout option of the man:lttng-enable-channel(1)
+command.
 +
 This option can be useful in workloads generating very large trace data
 throughput, where blocking the application is an acceptable trade-off to
@@ -1313,7 +1317,7 @@ affect application timings.
     https://github.com/lttng/lttng-ust/tree/master/doc/examples/clock-override[`examples/clock-override`].
 
 `LTTNG_UST_DEBUG`::
-    Activates `liblttng-ust`'s debug and error output if set to `1`.
+    If set, enable `liblttng-ust`'s debug and error output.
 
 `LTTNG_UST_GETCPU_PLUGIN`::
     Path to the shared object which acts as the `getcpu()` override
@@ -1332,9 +1336,8 @@ with time constraints on the process startup time.
 Default: {lttng_ust_register_timeout}.
 
 `LTTNG_UST_WITHOUT_BADDR_STATEDUMP`::
-    Prevents `liblttng-ust` from performing a base address state dump
-    (see the <<state-dump,LTTng-UST state dump>> section above) if
-    set to `1`.
+    If set, prevents `liblttng-ust` from performing a base address state
+    dump (see the <<state-dump,LTTng-UST state dump>> section above).
 
 
 include::common-footer.txt[]