X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=doc%2Fman%2Fbabeltrace-filter.lttng-utils.debug-info.7.txt;h=e640cdef39557b49b3cf90bee8245ffb5d8773b9;hb=a4c4205aa5847091494ce48fe8a78db1e36c8b68;hp=0882029640cb758d4bb3ddaaa1b0ce5ccd5eb9f6;hpb=b0bdda420195d901d82db314b8da9f2677624a14;p=babeltrace.git diff --git a/doc/man/babeltrace-filter.lttng-utils.debug-info.7.txt b/doc/man/babeltrace-filter.lttng-utils.debug-info.7.txt index 08820296..e640cdef 100644 --- a/doc/man/babeltrace-filter.lttng-utils.debug-info.7.txt +++ b/doc/man/babeltrace-filter.lttng-utils.debug-info.7.txt @@ -97,29 +97,58 @@ LTTng prerequisites A {comp} component can only analyze user space events generated by http://lttng.org[LTTng]{nbsp}2.8.0 or later. -The filter component needs the LTTng-UST events to contain the -`ip` and `vpid` fields in their context. - -To add those context fields with the man:lttng(1) command-line tool -before the tracers are active (before `lttng start`): +To get debugging information for LTTng-UST events which occur in +executables and libraries which the system's loader loads (what +you can see with man:ldd(1)): +. Add the `ip` and `vpid` context fields to user space event records: ++ +-- [role="term"] ---- $ lttng add-context --userspace --type=ip --type=vpid ---- +-- ++ +See man:lttng-add-context(1) for more details. -See man:lttng-add-context(1) for more information. +. Enable the LTTng-UST state dump events: ++ +-- +[role="term"] +---- +$ lttng enable-event --userspace 'lttng_ust_statedump:*' +---- +-- ++ +See man:lttng-enable-event(1) and man:lttng-ust(3) for more details. To get debugging information for LTTng-UST events which occur in -dynamically loaded objects, for example plugins, start the application -to trace with the LTTng-UST dynamic linking helper: +dynamically loaded objects, for example plugins: +. Do the previous steps (add context fields and enable + the LTTng-UST state dump events). + +. Enable the LTTng-UST dynamic linker tracing helper events: ++ +-- [role="term"] ---- -$ LD_PRELOAD=liblttng-ust-dl.so my-app +$ lttng enable-event --userspace 'lttng_ust_dl:*' ---- +-- ++ +See man:lttng-ust-dl(3) for more details. -See man:lttng-ust-dl(3) for more information. +. When you are ready to trace, start your application with the + `LD_PRELOAD` environment variable set to `liblttng-ust-dl.so`: ++ +-- +[role="term"] +---- +$ LD_PRELOAD=liblttng-ust-dl.so my-app +---- +-- Separate debugging information