X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=doc%2Fman%2Flttng-ust.3;h=2c58fba19197cbfe1fc89d86f3f328b1c6cf3f69;hb=b11abb674e50c67e3410ab2bd5d0a263e88b73ba;hp=de4271c2dd037969a6fdfdd6a3dac2d6268b56c1;hpb=7c5019232f7bda13ab10f346c5bdd2d467b983c1;p=lttng-ust.git diff --git a/doc/man/lttng-ust.3 b/doc/man/lttng-ust.3 index de4271c2..2c58fba1 100644 --- a/doc/man/lttng-ust.3 +++ b/doc/man/lttng-ust.3 @@ -33,9 +33,13 @@ script, through an example: .nf To create a tracepoint provider, within a build tree similar to -examples/easy-ust installed with lttng-ust documentation, a -sample_component_provider.h for the general layout. This manpage will -focus on the various types that can be recorded into a trace event: +examples/easy-ust installed with lttng-ust documentation, see +sample_component_provider.h for the general layout. You will need to +define TRACEPOINT_CREATE_PROBES before including your tracepoint +provider probe in one source file of your application. See tp.c from +easy-ust for an example of a tracepoint probe source file. This manpage +will focus on the various types that can be recorded into a trace +event: TRACEPOINT_EVENT( /* @@ -342,6 +346,13 @@ Virtual process ID: process ID as seen from the point of view of the process namespace. .PP +.PP +.IP "ip" +Instruction pointer: Enables recording of the exact location where a tracepoint +was emitted. Can be used to reverse-lookup the source location that caused the +event to be emitted. +.PP + .PP .IP "procname" Thread name, as set by exec() or prctl(). It is recommended that @@ -355,6 +366,33 @@ Pthread identifier. Can be used on architectures where pthread_t maps nicely to an unsigned long type. .PP +.SH "BASE ADDRESS STATEDUMP (Experimental feature)" + +.PP +Warning: This is an experimental feature known to cause deadlocks when the +traced application uses fork, clone or daemon. Only use it for debugging and +testing. Do NOT use it in production. + +If an application that uses liblttng-ust.so becomes part of a session, +information about its currently loaded shared objects will be traced to the +session at session-enable time. To record this information, the following event +needs to be enabled: +.PP +.IP "ust_baddr_statedump:soinfo" +This event is used to trace a currently loaded shared object. The base address +(where the dynamic linker has placed the shared object) is recorded in the +"baddr" field. The path to the shared object gets recorded in the +"sopath" field (as string). The file size of the loaded object (in +bytes) is recorded to the "size" field and its time of last modification +(in seconds since Epoch) is recorded in the "mtime" field. +.PP +If the event above is enabled, a series of "ust_baddr_statedump:soinfo" +events is recorded at session-enable time. It represents the state of +currently loaded shared objects for the traced process. If this +information gets combined with the lttng-ust-dl(3) instrumentation, all +aspects of dynamic loading that are relevant for symbol and +line number lookup are traced by LTTng. +.PP .SH "ENVIRONMENT VARIABLES" .PP @@ -371,19 +409,22 @@ specified in milliseconds. The value 0 means "don't wait". The value recommended for applications with time constraints on the process startup time. .PP +.IP "LTTNG_UST_WITH_EXPERIMENTAL_BADDR_STATEDUMP" +Experimentally allow liblttng-ust to perform a base-address statedump on session-enable. +.PP .SH "SEE ALSO" .PP lttng-gen-tp(1), lttng(1), babeltrace(1), lttng-ust-cyg-profile(3), -lttng-sessiond(8) +lttng-ust-dl(3), lttng-sessiond(8) .PP .SH "COMPATIBILITY" .PP Older lttng-ust libraries reject more recent, and incompatible, probe -providers. Newer lttng-ust librairies accept older probe providers, even +providers. Newer lttng-ust libraries accept older probe providers, even though some newer features might not be available with those providers. .PP