`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 man:ipc_namespaces(7) namespace in the proc filesystem.
+
+`mnt_ns`::
+ Mount points namespace: inode number of the current
+ man:mount_namespaces(7) in the proc filesystem.
+
+`net_ns`::
+ Network devices, stacks, ports namespace: inode number of the
+ current man:network_namespaces(7) 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 man:uts_namespaces(7) in the proc filesystem.
+
+The following man:credentials(7) context fields are supported by LTTng-UST:
+
+`vuid`::
+ Virtual real user ID: real user ID as seen from the point of view of
+ the current man:user_namespaces(7).
+
+`vgid`::
+ Virtual real group ID: real group ID as seen from the point of view of
+ the current man:user_namespaces(7).
+
+`veuid`::
+ Virtual effective user ID: effective user ID as seen from the point of
+ view of the current man:user_namespaces(7).
+
+`vegid`::
+ Virtual effective group ID: effective group ID as seen from the point of
+ view of the current man:user_namespaces(7).
+
+`vsuid`::
+ Virtual saved set-user ID: saved set-user ID as seen from the point of
+ view of the current man:user_namespaces(7).
+
+`vsgid`::
+ Virtual saved set-group ID: saved set-group ID as seen from the point of
+ view of the current man:user_namespaces(7).
[[state-dump]]
EXAMPLE
-------
NOTE: A few examples are available in the
-https://github.com/lttng/lttng-ust/tree/master/doc/examples[`doc/examples`]
+https://github.com/lttng/lttng-ust/tree/v{lttng_version}/doc/examples[`doc/examples`]
directory of LTTng-UST's source tree.
This example shows all the features documented in the previous
`$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
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`].
+ https://github.com/lttng/lttng-ust/tree/v{lttng_version}/doc/examples/clock-override[`examples/clock-override`].
`LTTNG_UST_DEBUG`::
If set, enable `liblttng-ust`'s debug and error output.
Path to the shared object which acts as the `getcpu()` 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/getcpu-override[`examples/getcpu-override`].
+ https://github.com/lttng/lttng-ust/tree/v{lttng_version}/doc/examples/getcpu-override[`examples/getcpu-override`].
`LTTNG_UST_REGISTER_TIMEOUT`::
Waiting time for the _registration done_ session daemon command