Add support for kvm x86 specific tracepoints

[lttng-modules.git] / README

diff --git a/README b/README
index abbfd27746926f6a1426e81ee96b1c4c9e53a4e3..b7d8b9f8e6c271026a8f27e491455bff7fb77b59 100644 (file)
--- a/README
+++ b/README
@@ -1,9 +1,9 @@
-LTTng 2.0 modules
+LTTng 2.x modules
 
 Mathieu Desnoyers
-February 8, 2012
+March 29, 2013
 
-LTTng 2.0 kernel modules build against a vanilla or distribution kernel, without
+LTTng 2.x kernel modules build against a vanilla or distribution kernel, without
 need for additional patches. Other features:
 
 - Produces CTF (Common Trace Format) natively,
@@ -38,7 +38,9 @@ http://lttng.org/lttng2.0
 
 So far, it has been tested on vanilla Linux kernels 2.6.38, 2.6.39, 3.0,
 3.1, 3.2, 3.3 (on x86 32/64-bit, and powerpc 32-bit at the moment, build
-tested on ARM). It should work fine with newer kernels and other
+tested on ARM), 3.4, 3.5, 3.8, 3.9-rc on x86 64-bit. Kernels 2.6.32 to
+2.6.34 need up to 3 patches applied (refer to linux-patches within the
+lttng-modules tree). It should work fine with newer kernels and other
 architectures, but expect build issues with kernels older than 2.6.36.
 The clock source currently used is the standard gettimeofday (slower,
 less scalable and less precise than the LTTng 0.x clocks).  Support for
@@ -48,9 +50,44 @@ 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 required
+
+CONFIG_MODULES: required
+  * Kernel modules support.
+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