diff options
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/ftrace-design.txt | 26 | ||||
| -rw-r--r-- | Documentation/trace/ftrace.txt | 2 |
2 files changed, 1 insertions, 27 deletions
diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt index 3f669b9e8852..dd5f916b351d 100644 --- a/Documentation/trace/ftrace-design.txt +++ b/Documentation/trace/ftrace-design.txt @@ -102,30 +102,6 @@ extern void mcount(void); EXPORT_SYMBOL(mcount); -HAVE_FUNCTION_TRACE_MCOUNT_TEST -------------------------------- - -This is an optional optimization for the normal case when tracing is turned off -in the system. If you do not enable this Kconfig option, the common ftrace -code will take care of doing the checking for you. - -To support this feature, you only need to check the function_trace_stop -variable in the mcount function. If it is non-zero, there is no tracing to be -done at all, so you can return. - -This additional pseudo code would simply be: -void mcount(void) -{ - /* save any bare state needed in order to do initial checking */ - -+ if (function_trace_stop) -+ return; - - extern void (*ftrace_trace_function)(unsigned long, unsigned long); - if (ftrace_trace_function != ftrace_stub) -... - - HAVE_FUNCTION_GRAPH_TRACER -------------------------- @@ -328,8 +304,6 @@ void mcount(void) void ftrace_caller(void) { - /* implement HAVE_FUNCTION_TRACE_MCOUNT_TEST if you desire */ - /* save all state needed by the ABI (see paragraph above) */ unsigned long frompc = ...; diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 2479b2a0c77c..4da42616939f 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -1515,7 +1515,7 @@ Doing the same with chrt -r 5 and function-trace set. <idle>-0 3d.h4 1us+: 0:120:R + [003] 2448: 94:R sleep <idle>-0 3d.h4 2us : ttwu_do_activate.constprop.87 <-try_to_wake_up <idle>-0 3d.h3 3us : check_preempt_curr <-ttwu_do_wakeup - <idle>-0 3d.h3 3us : resched_task <-check_preempt_curr + <idle>-0 3d.h3 3us : resched_curr <-check_preempt_curr <idle>-0 3dNh3 4us : task_woken_rt <-ttwu_do_wakeup <idle>-0 3dNh3 4us : _raw_spin_unlock <-try_to_wake_up <idle>-0 3dNh3 4us : sub_preempt_count <-_raw_spin_unlock |