From 47491cdffd394f09524657e9be1e90d4bb644f2f Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 15 Oct 2019 15:58:16 -0400 Subject: [PATCH] README.md: Document LTTNG_TRACEPOINT_EVENT Suggested-by: David Boles Signed-off-by: Mathieu Desnoyers --- README.md | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/README.md b/README.md index 17553e63..450f3630 100644 --- a/README.md +++ b/README.md @@ -94,6 +94,19 @@ available from LTTng: - `CONFIG_KALLSYMS_ALL`: state dump of mapping between block device number and name +Customization/Extension +----------------------- + +The lttng-modules source includes definitions for the actual callback +functions that will be attached to the kernel tracepoints by lttng. +The lttng-modules project implements its own macros generating these +callbacks: the LTTNG_TRACEPOINT_EVENT macro family found in +instrumentation/events/lttng-module/. In order to show up in a +lttng-modules trace, a kernel tracepoint must be defined within the +kernel tree, and also defined within lttng-modules with the +LTTNG_TRACEPOINT_EVENT macro family. Customizations or extensions must +be done by modifying instances of these macros within the lttng-modules +source. Usage ----- -- 2.34.1