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.
+`LTTNG_UST_ALLOW_BLOCKING`::
+ 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 the configured timeout is reached.
+
---
-`0`::
- 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.
---
-+
-Default: {lttng_ust_blocking_retry_timeout}.
+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
prevent discarding event records.
+
-WARNING: Setting this environment variable to a non-zero value may
-significantly affect application timings.
+WARNING: Setting this environment variable may significantly
+affect application timings.
`LTTNG_UST_CLOCK_PLUGIN`::
Path to the shared object which acts as the clock override plugin.
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
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[]