tracing: Fix formatting of trace README file

Fix the formatting of the README file in the trace debugfs to fit in
an 80 character window.

Also add a comment about the event trigger counter with regards to
traceon and traceoff.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2ced5e5..7857ea9 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3519,91 +3519,103 @@ static const char readme_msg[] =
        "  instances\t\t- Make sub-buffers with: mkdir instances/foo\n"
        "\t\t\t  Remove sub-buffer with rmdir\n"
        "  trace_options\t\t- Set format or modify how tracing happens\n"
-       "\t\t\t  Disable an option by adding a suffix 'no' to the option name\n"
+       "\t\t\t  Disable an option by adding a suffix 'no' to the\n"
+       "\t\t\t  option name\n"
 #ifdef CONFIG_DYNAMIC_FTRACE
        "\n  available_filter_functions - list of functions that can be filtered on\n"
-       "  set_ftrace_filter\t- echo function name in here to only trace these functions\n"
-       "             accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
-       "             modules: Can select a group via module\n"
-       "              Format: :mod:<module-name>\n"
-       "             example: echo :mod:ext3 > set_ftrace_filter\n"
-       "            triggers: a command to perform when function is hit\n"
-       "              Format: <function>:<trigger>[:count]\n"
-       "             trigger: traceon, traceoff\n"
-       "                      enable_event:<system>:<event>\n"
-       "                      disable_event:<system>:<event>\n"
+       "  set_ftrace_filter\t- echo function name in here to only trace these\n"
+       "\t\t\t  functions\n"
+       "\t     accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
+       "\t     modules: Can select a group via module\n"
+       "\t      Format: :mod:<module-name>\n"
+       "\t     example: echo :mod:ext3 > set_ftrace_filter\n"
+       "\t    triggers: a command to perform when function is hit\n"
+       "\t      Format: <function>:<trigger>[:count]\n"
+       "\t     trigger: traceon, traceoff\n"
+       "\t\t      enable_event:<system>:<event>\n"
+       "\t\t      disable_event:<system>:<event>\n"
 #ifdef CONFIG_STACKTRACE
-       "                      stacktrace\n"
+       "\t\t      stacktrace\n"
 #endif
 #ifdef CONFIG_TRACER_SNAPSHOT
-       "                      snapshot\n"
+       "\t\t      snapshot\n"
 #endif
-       "             example: echo do_fault:traceoff > set_ftrace_filter\n"
-       "                      echo do_trap:traceoff:3 > set_ftrace_filter\n"
-       "             The first one will disable tracing every time do_fault is hit\n"
-       "             The second will disable tracing at most 3 times when do_trap is hit\n"
-       "               The first time do trap is hit and it disables tracing, the counter\n"
-       "               will decrement to 2. If tracing is already disabled, the counter\n"
-       "               will not decrement. It only decrements when the trigger did work\n"
-       "             To remove trigger without count:\n"
-       "               echo '!<function>:<trigger> > set_ftrace_filter\n"
-       "             To remove trigger with a count:\n"
-       "               echo '!<function>:<trigger>:0 > set_ftrace_filter\n"
+       "\t     example: echo do_fault:traceoff > set_ftrace_filter\n"
+       "\t              echo do_trap:traceoff:3 > set_ftrace_filter\n"
+       "\t     The first one will disable tracing every time do_fault is hit\n"
+       "\t     The second will disable tracing at most 3 times when do_trap is hit\n"
+       "\t       The first time do trap is hit and it disables tracing, the\n"
+       "\t       counter will decrement to 2. If tracing is already disabled,\n"
+       "\t       the counter will not decrement. It only decrements when the\n"
+       "\t       trigger did work\n"
+       "\t     To remove trigger without count:\n"
+       "\t       echo '!<function>:<trigger> > set_ftrace_filter\n"
+       "\t     To remove trigger with a count:\n"
+       "\t       echo '!<function>:<trigger>:0 > set_ftrace_filter\n"
        "  set_ftrace_notrace\t- echo function name in here to never trace.\n"
-       "            accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
-       "            modules: Can select a group via module command :mod:\n"
-       "            Does not accept triggers\n"
+       "\t    accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
+       "\t    modules: Can select a group via module command :mod:\n"
+       "\t    Does not accept triggers\n"
 #endif /* CONFIG_DYNAMIC_FTRACE */
 #ifdef CONFIG_FUNCTION_TRACER
-       "  set_ftrace_pid\t- Write pid(s) to only function trace those pids (function)\n"
+       "  set_ftrace_pid\t- Write pid(s) to only function trace those pids\n"
+       "\t\t    (function)\n"
 #endif
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
        "  set_graph_function\t- Trace the nested calls of a function (function_graph)\n"
        "  max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n"
 #endif
 #ifdef CONFIG_TRACER_SNAPSHOT
-       "\n  snapshot\t\t- Like 'trace' but shows the content of the static snapshot buffer\n"
-       "\t\t\t  Read the contents for more information\n"
+       "\n  snapshot\t\t- Like 'trace' but shows the content of the static\n"
+       "\t\t\t  snapshot buffer. Read the contents for more\n"
+       "\t\t\t  information\n"
 #endif
 #ifdef CONFIG_STACK_TRACER
        "  stack_trace\t\t- Shows the max stack trace when active\n"
        "  stack_max_size\t- Shows current max stack size that was traced\n"
-       "\t\t\t  Write into this file to reset the max size (trigger a new trace)\n"
+       "\t\t\t  Write into this file to reset the max size (trigger a\n"
+       "\t\t\t  new trace)\n"
 #ifdef CONFIG_DYNAMIC_FTRACE
-       "  stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace traces\n"
+       "  stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace\n"
+       "\t\t\t  traces\n"
 #endif
 #endif /* CONFIG_STACK_TRACER */
        "  events/\t\t- Directory containing all trace event subsystems:\n"
        "      enable\t\t- Write 0/1 to enable/disable tracing of all events\n"
        "  events/<system>/\t- Directory containing all trace events for <system>:\n"
-       "      enable\t\t- Write 0/1 to enable/disable tracing of all <system> events\n"
+       "      enable\t\t- Write 0/1 to enable/disable tracing of all <system>\n"
+       "\t\t\t  events\n"
        "      filter\t\t- If set, only events passing filter are traced\n"
-       "  events/<system>/<event>/\t- Directory containing control files for <event>:\n"
+       "  events/<system>/<event>/\t- Directory containing control files for\n"
+       "\t\t\t  <event>:\n"
        "      enable\t\t- Write 0/1 to enable/disable tracing of <event>\n"
        "      filter\t\t- If set, only events passing filter are traced\n"
        "      trigger\t\t- If set, a command to perform when event is hit\n"
-       "            Format: <trigger>[:count][if <filter>]\n"
-       "           trigger: traceon, traceoff\n"
-       "                    enable_event:<system>:<event>\n"
-       "                    disable_event:<system>:<event>\n"
+       "\t    Format: <trigger>[:count][if <filter>]\n"
+       "\t   trigger: traceon, traceoff\n"
+       "\t            enable_event:<system>:<event>\n"
+       "\t            disable_event:<system>:<event>\n"
 #ifdef CONFIG_STACKTRACE
-       "                    stacktrace\n"
+       "\t\t    stacktrace\n"
 #endif
 #ifdef CONFIG_TRACER_SNAPSHOT
-       "                    snapshot\n"
+       "\t\t    snapshot\n"
 #endif
-       "           example: echo traceoff > events/block/block_unplug/trigger\n"
-       "                    echo traceoff:3 > events/block/block_unplug/trigger\n"
-       "                    echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > events/block/block_unplug/trigger\n"
-       "           The first disables tracing every time block_unplug is hit.\n"
-       "           The second disables tracing the first 3 times block_unplug is hit.\n"
-       "           The third enables the kmalloc event the first 3 times block_unplug\n"
-       "             is hit and has value of greater than 1 for the 'nr_rq' event field.\n"
-       "           To remove a trigger without a count:\n"
-       "             echo '!<trigger> > <system>/<event>/trigger\n"
-       "           To remove a trigger with a count:\n"
-       "             echo '!<trigger>:0 > <system>/<event>/trigger\n"
-       "           Filters can be ignored when removing a trigger.\n"
+       "\t   example: echo traceoff > events/block/block_unplug/trigger\n"
+       "\t            echo traceoff:3 > events/block/block_unplug/trigger\n"
+       "\t            echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n"
+       "\t                  events/block/block_unplug/trigger\n"
+       "\t   The first disables tracing every time block_unplug is hit.\n"
+       "\t   The second disables tracing the first 3 times block_unplug is hit.\n"
+       "\t   The third enables the kmalloc event the first 3 times block_unplug\n"
+       "\t     is hit and has value of greater than 1 for the 'nr_rq' event field.\n"
+       "\t   Like function triggers, the counter is only decremented if it\n"
+       "\t    enabled or disabled tracing.\n"
+       "\t   To remove a trigger without a count:\n"
+       "\t     echo '!<trigger> > <system>/<event>/trigger\n"
+       "\t   To remove a trigger with a count:\n"
+       "\t     echo '!<trigger>:0 > <system>/<event>/trigger\n"
+       "\t   Filters can be ignored when removing a trigger.\n"
 ;
 
 static ssize_t