X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=doc%2Fman%2Flttng-ust.3.txt;h=43bc226565ceaa3b3d268f882c929df86b8911d7;hb=6f97f9c2bbc74605e3de2b05333ecf25fa52d6fc;hp=1d69221d122f269311727c463b26f484ee379834;hpb=6488ae4ce8308349a872aa2bd744103608464cc5;p=lttng-ust.git

diff --git a/doc/man/lttng-ust.3.txt b/doc/man/lttng-ust.3.txt
index 1d69221d..43bc2265 100644
--- a/doc/man/lttng-ust.3.txt
+++ b/doc/man/lttng-ust.3.txt
@@ -758,7 +758,7 @@ LTTng-UST state dump
 ~~~~~~~~~~~~~~~~~~~~
 If an application that uses `liblttng-ust` becomes part of a tracing
 session, information about its currently loaded shared objects, their
-build IDs, and their debug link informations are emitted as events
+build IDs, and their debug link information are emitted as events
 by the tracer.
 
 The following LTTng-UST state dump events exist and must be enabled
@@ -1088,23 +1088,48 @@ int main(int argc, char* argv[])
 
 ENVIRONMENT VARIABLES
 ---------------------
-`LTTNG_UST_DEBUG`::
-    Activate `liblttng-ust` debug and error output.
-
-`LTTNG_UST_REGISTER_TIMEOUT`::
-    Specify how long the applications should wait for the
-    _registration done_ session daemon command before proceeding to
-    execute the main program (milliseconds).
+`LTTNG_HOME`::
+    Alternative user's home directory. This variable is useful when the
+    user running the instrumented application has a non-writable home
+    directory.
 +
-The value 0 means _do not wait_. The value -1 means _wait forever_.
-Setting this environment variable to 0 is recommended for applications
-with time constraints on the process startup time.
+Unix sockets used for the communication between `liblttng-ust` and the
+LTTng session and consumer daemons (part of the LTTng-tools project)
+are located in a specific directory under `$LTTNG_HOME` (or `$HOME` if
+`$LTTNG_HOME` is not set).
+
+`LTTNG_UST_BLOCKING_RETRY_TIMEOUT`::
+    Maximum duration (milliseconds) to retry event tracing when
+    there's no space left for the event record in the sub-buffer.
 +
-Default: 3000.
+--
+`0` (default)::
+    Never block the application.
+
+Positive value::
+    Block the application for the specified number of milliseconds. If
+    there's no space left after this duration, discard the event
+    record.
+
+Negative value::
+    Block the application until there's space left for the event record.
+--
++
+This option can be useful in workloads generating very large trace data
+throughput, where blocking the application is an acceptable trade-off to
+prevent discarding event records.
++
+WARNING: Setting this environment variable to a non-zero value may
+significantly affect application timings.
 
-`LTTNG_UST_WITHOUT_BADDR_STATEDUMP`::
-    Prevent `liblttng-ust` from performing a base address state dump
-    (see the <<state-dump,LTTng-UST state dump>> section above).
+`LTTNG_UST_CLOCK_PLUGIN`::
+    Path to the shared object which acts as the clock override plugin.
+    An example of such a plugin can be found in the LTTng-UST
+    documentation under
+    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`.
 
 `LTTNG_UST_GETCPU_PLUGIN`::
     Path to the shared object which acts as the `getcpu()` override
@@ -1112,11 +1137,38 @@ Default: 3000.
     documentation under
     https://github.com/lttng/lttng-ust/tree/master/doc/examples/getcpu-override[`examples/getcpu-override`].
 
-`LTTNG_UST_CLOCK_PLUGIN`::
-    Path to the shared object which acts as the clock override plugin.
-    An example of such a plugin can be found in the LTTng-UST
-    documentation under
-    https://github.com/lttng/lttng-ust/tree/master/doc/examples/clock-override[`examples/clock-override`].
+`LTTNG_UST_REGISTER_TIMEOUT`::
+    Waiting time for the _registration done_ session daemon command
+    before proceeding to execute the main program (milliseconds).
++
+The value `0` means _do not wait_. The value `-1` means _wait forever_.
+Setting this environment variable to `0` is recommended for applications
+with time constraints on the process startup time.
++
+Default: {lttng_ust_register_timeout}.
+
+`LTTNG_UST_BLOCKING_RETRY_TIMEOUT`::
+    Maximum time during which event tracing retry is attempted on buffer
+    full condition (millliseconds). Setting this environment to non-zero
+    value effectively blocks the application on buffer full condition.
+    Setting this environment variable to non-zero values may
+    significantly affect application timings. Setting this to a negative
+    value may block the application indefinitely if there is no consumer
+    emptying the ring buffer. The delay between retry attempts is the
+    minimum between the specified timeout value and 100ms. This option
+    can be useful in workloads generating very large trace data
+    throughput, where blocking the application is an acceptable
+    trade-off to not discard events. _Use with caution_.
++
+The value `0` means _do not retry_. The value `-1` means _retry forever_.
+Value > `0` means a maximum timeout of the given value.
++
+Default: {lttng_ust_blocking_retry_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`.
 
 
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