diff options
| author | Chunyan Zhang <chunyan.zhang@spreadtrum.com> | 2017-03-23 14:13:25 +0800 |
|---|---|---|
| committer | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2017-08-25 17:58:34 +0300 |
| commit | 39fccd2fc33c95de8358451f58c52b9e4b828ddd (patch) | |
| tree | 3da4185e41c4483b95eda9612a0dc12c759bef2a /Documentation/trace | |
| parent | 71c488f32b071bfb5cfe9ddf682cd2e0c310c75d (diff) | |
stm class: Document the stm_ftrace
This patch adds a description to the stm_ftrace device source, an
interface for collecting Ftrace's function trace information via
STM devices.
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/stm.txt | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/Documentation/trace/stm.txt b/Documentation/trace/stm.txt index 11cff47eecce..03765750104b 100644 --- a/Documentation/trace/stm.txt +++ b/Documentation/trace/stm.txt @@ -83,7 +83,7 @@ by writing the name of the desired stm device there, for example: $ echo dummy_stm.0 > /sys/class/stm_source/console/stm_source_link For examples on how to use stm_source interface in the kernel, refer -to stm_console or stm_heartbeat drivers. +to stm_console, stm_heartbeat or stm_ftrace drivers. Each stm_source device will need to assume a master and a range of channels, depending on how many channels it requires. These are @@ -107,5 +107,16 @@ console in the STP stream, create a "console" policy entry (see the beginning of this text on how to do that). When initialized, it will consume one channel. +stm_ftrace +========== + +This is another "stm_source" device, once the stm_ftrace has been +linked with an stm device, and if "function" tracer is enabled, +function address and parent function address which Ftrace subsystem +would store into ring buffer will be exported via the stm device at +the same time. + +Currently only Ftrace "function" tracer is supported. + [1] https://software.intel.com/sites/default/files/managed/d3/3c/intel-th-developer-manual.pdf [2] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0444b/index.html |