`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
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`::
- 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 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.
+
-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.
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`::
- 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
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
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[]
projects / lttng-ust.git / blobdiff