From d0a5ff7d8479de94f1082055d1d940d660027fc8 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Fri, 6 Apr 2012 12:32:22 -0400 Subject: [PATCH] Fix: document required and optional kernel config options in README Signed-off-by: Mathieu Desnoyers --- README | 41 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-) diff --git a/README b/README index abbfd277..ac0dc888 100644 --- a/README +++ b/README @@ -1,7 +1,7 @@ LTTng 2.0 modules Mathieu Desnoyers -February 8, 2012 +April 6, 2012 LTTng 2.0 kernel modules build against a vanilla or distribution kernel, without need for additional patches. Other features: @@ -48,9 +48,42 @@ LTTng 0.x patchset, but the lttng-modules 2.0 replace the lttng-modules 0.x, so both tracers cannot be installed at the same time for a given kernel version. -LTTng-modules depends on having kallsyms enabled in the kernel it is -built against. Ideally, if you want to have system call tracing, the -"Trace Syscalls" feature should be enabled too. + +* Kernel config options requied + +CONFIG_KALLSYMS: required + * See wrapper/ files. This is necessary until the few required missing + symbols are exported to GPL modules from mainline. +CONFIG_HIGH_RES_TIMERS: required + * Needed for LTTng 2.0 clock source. +CONFIG_TRACEPOINTS: required + kernel tracepoint instrumentation + * Enabled as side-effect of any of the perf/ftrace/blktrace + instrumentation features. + + +* Kernel config options supported (optional) + +The following kernel configuration options will affect the features +available from LTTng: + + +CONFIG_HAVE_SYSCALL_TRACEPOINTS: + system call tracing + lttng enable-event -k --syscall + lttng enable-event -k -a +CONFIG_PERF_EVENTS: + performance counters + lttng add-context -t perf:* +CONFIG_EVENT_TRACING: + needed to allow block layer tracing +CONFIG_KPROBES: + Dynamic probe. + lttng enable-event -k --probe ... +CONFIG_KRETPROBES: + Dynamic function entry/return probe. + lttng enable-event -k --function ... + * Note about Perf PMU counters support -- 2.34.1