diff options
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/coresight/panic.rst | 4 | ||||
| -rw-r--r-- | Documentation/trace/ftrace.rst | 17 | ||||
| -rw-r--r-- | Documentation/trace/index.rst | 98 | ||||
| -rw-r--r-- | Documentation/trace/tracepoints.rst | 17 |
4 files changed, 109 insertions, 27 deletions
diff --git a/Documentation/trace/coresight/panic.rst b/Documentation/trace/coresight/panic.rst index a58aa914c241..6e4bde953cae 100644 --- a/Documentation/trace/coresight/panic.rst +++ b/Documentation/trace/coresight/panic.rst @@ -67,8 +67,8 @@ Trace data captured at the time of panic, can be read from rebooted kernel or from crashdump kernel using a special device file /dev/crash_tmc_xxx. This device file is created only when there is a valid crashdata available. -General flow of trace capture and decode incase of kernel panic -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +General flow of trace capture and decode in case of kernel panic +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1. Enable source and sink on all the cores using the sysfs interface. ETR sinks should have trace buffers allocated from reserved memory, by selecting "resrv" buffer mode from sysfs. diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 2b74f96d09d5..af66a05e18cc 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -1205,6 +1205,19 @@ Here are the available options: default instance. The only way the top level instance has this flag cleared, is by it being set in another instance. + copy_trace_marker + If there are applications that hard code writing into the top level + trace_marker file (/sys/kernel/tracing/trace_marker or trace_marker_raw), + and the tooling would like it to go into an instance, this option can + be used. Create an instance and set this option, and then all writes + into the top level trace_marker file will also be redirected into this + instance. + + Note, by default this option is set for the top level instance. If it + is disabled, then writes to the trace_marker or trace_marker_raw files + will not be written into the top level file. If no instance has this + option set, then a write will error with the errno of ENODEV. + annotate It is sometimes confusing when the CPU buffers are full and one CPU buffer had a lot of events recently, thus @@ -3077,7 +3090,7 @@ Notice that we lost the sys_nanosleep. # cat set_ftrace_filter hrtimer_run_queues hrtimer_run_pending - hrtimer_init + hrtimer_setup hrtimer_cancel hrtimer_try_to_cancel hrtimer_forward @@ -3115,7 +3128,7 @@ Again, now we want to append. # cat set_ftrace_filter hrtimer_run_queues hrtimer_run_pending - hrtimer_init + hrtimer_setup hrtimer_cancel hrtimer_try_to_cancel hrtimer_forward diff --git a/Documentation/trace/index.rst b/Documentation/trace/index.rst index 2c991dc96ace..cc1dc5a087e8 100644 --- a/Documentation/trace/index.rst +++ b/Documentation/trace/index.rst @@ -1,39 +1,103 @@ -========================== -Linux Tracing Technologies -========================== +================================ +Linux Tracing Technologies Guide +================================ + +Tracing in the Linux kernel is a powerful mechanism that allows +developers and system administrators to analyze and debug system +behavior. This guide provides documentation on various tracing +frameworks and tools available in the Linux kernel. + +Introduction to Tracing +----------------------- + +This section provides an overview of Linux tracing mechanisms +and debugging approaches. .. toctree:: - :maxdepth: 2 + :maxdepth: 1 - ftrace-design + debugging + tracepoints tracepoint-analysis + ring-buffer-map + +Core Tracing Frameworks +----------------------- + +The following are the primary tracing frameworks integrated into +the Linux kernel. + +.. toctree:: + :maxdepth: 1 + ftrace + ftrace-design ftrace-uses - fprobe kprobes kprobetrace - uprobetracer fprobetrace - tracepoints + fprobe + ring-buffer-design + +Event Tracing and Analysis +-------------------------- + +A detailed explanation of event tracing mechanisms and their +applications. + +.. toctree:: + :maxdepth: 1 + events events-kmem events-power events-nmi events-msr - mmiotrace + boottime-trace histogram histogram-design - boottime-trace - debugging - hwlat_detector - osnoise-tracer - timerlat-tracer + +Hardware and Performance Tracing +-------------------------------- + +This section covers tracing features that monitor hardware +interactions and system performance. + +.. toctree:: + :maxdepth: 1 + intel_th - ring-buffer-design - ring-buffer-map stm sys-t coresight/index - user_events rv/index hisi-ptt + mmiotrace + hwlat_detector + osnoise-tracer + timerlat-tracer + +User-Space Tracing +------------------ + +These tools allow tracing user-space applications and +interactions. + +.. toctree:: + :maxdepth: 1 + + user_events + uprobetracer + +Additional Resources +-------------------- + +For more details, refer to the respective documentation of each +tracing tool and framework. + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/trace/tracepoints.rst b/Documentation/trace/tracepoints.rst index decabcc77b56..b35c40e3abbe 100644 --- a/Documentation/trace/tracepoints.rst +++ b/Documentation/trace/tracepoints.rst @@ -71,7 +71,7 @@ In subsys/file.c (where the tracing statement must be added):: void somefct(void) { ... - trace_subsys_eventname(arg, task); + trace_subsys_eventname_tp(arg, task); ... } @@ -129,12 +129,12 @@ within an if statement with the following:: for (i = 0; i < count; i++) tot += calculate_nuggets(); - trace_foo_bar(tot); + trace_foo_bar_tp(tot); } -All trace_<tracepoint>() calls have a matching trace_<tracepoint>_enabled() +All trace_<tracepoint>_tp() calls have a matching trace_<tracepoint>_enabled() function defined that returns true if the tracepoint is enabled and -false otherwise. The trace_<tracepoint>() should always be within the +false otherwise. The trace_<tracepoint>_tp() should always be within the block of the if (trace_<tracepoint>_enabled()) to prevent races between the tracepoint being enabled and the check being seen. @@ -143,7 +143,10 @@ the static_key of the tracepoint to allow the if statement to be implemented with jump labels and avoid conditional branches. .. note:: The convenience macro TRACE_EVENT provides an alternative way to - define tracepoints. Check http://lwn.net/Articles/379903, + define tracepoints. Note, DECLARE_TRACE(foo) creates a function + "trace_foo_tp()" whereas TRACE_EVENT(foo) creates a function + "trace_foo()", and also exposes the tracepoint as a trace event in + /sys/kernel/tracing/events directory. Check http://lwn.net/Articles/379903, http://lwn.net/Articles/381064 and http://lwn.net/Articles/383362 for a series of articles with more details. @@ -159,7 +162,9 @@ In a C file:: void do_trace_foo_bar_wrapper(args) { - trace_foo_bar(args); + trace_foo_bar_tp(args); // for tracepoints created via DECLARE_TRACE + // or + trace_foo_bar(args); // for tracepoints created via TRACE_EVENT } In the header file:: |