`vpid`::
Virtual process ID: process ID as seen from the point of view of
- the process namespace.
+ the current man:pid_namespaces(7).
`vtid`::
Virtual thread ID: thread ID as seen from the point of view of
- the process namespace.
+ the current man:pid_namespaces(7).
+
+The following man:namespaces(7) context fields are supported by LTTng-UST:
+
+`cgroup_ns`::
+ Cgroup root directory namespace: inode number of the current
+ man:cgroup_namespaces(7) in the proc filesystem.
+
+`ipc_ns`::
+ System V IPC, POSIX message queues namespace: inode number of the
+ current IPC namespace in the proc filesystem.
+
+`mnt_ns`::
+ Mount points namespace: inode number of the current Mount namespace
+ in the proc filesystem.
+
+`net_ns`::
+ Network devices, stacks, ports namespace: inode number of the
+ current Network namespace in the proc filesystem.
+
+`pid_ns`::
+ Process IDs namespace: inode number of the current
+ man:pid_namespaces(7) in the proc filesystem.
+
+`user_ns`::
+ User and group IDs namespace: inode number of the current
+ man:user_namespaces(7) in the proc filesystem.
+
+`uts_ns`::
+ Hostname and NIS domain name namespace: inode number of the
+ current UTS namespace in the proc filesystem.
[[state-dump]]
`$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
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[]