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.
-+
---
-`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.
---
+`LTTNG_UST_ALLOW_BLOCKING`::
+ If set, allow 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.
+
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_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`.
+ 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[]