From: "Steven Rostedt (VMware)" <[email protected]> The unlikely/likely branch profiler now gets called even if the if statement is a constant (always goes in one direction without a compare). Add a value to denote this in the likely/unlikely tracer as well.
Signed-off-by: Steven Rostedt (VMware) <[email protected]> --- kernel/trace/trace_branch.c | 17 +++++++++-------- kernel/trace/trace_entries.h | 6 ++++-- 2 files changed, 13 insertions(+), 10 deletions(-) diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index fd483d74f8e1..4d8fdf3184dc 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -27,7 +27,7 @@ static DEFINE_MUTEX(branch_tracing_mutex); static struct trace_array *branch_tracer; static void -probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) +probe_likely_condition(struct ftrace_likely_data *f, int val, int expect) { struct trace_event_call *call = &event_branch; struct trace_array *tr = branch_tracer; @@ -68,16 +68,17 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) entry = ring_buffer_event_data(event); /* Strip off the path, only save the file */ - p = f->file + strlen(f->file); - while (p >= f->file && *p != '/') + p = f->data.file + strlen(f->data.file); + while (p >= f->data.file && *p != '/') p--; p++; - strncpy(entry->func, f->func, TRACE_FUNC_SIZE); + strncpy(entry->func, f->data.func, TRACE_FUNC_SIZE); strncpy(entry->file, p, TRACE_FILE_SIZE); entry->func[TRACE_FUNC_SIZE] = 0; entry->file[TRACE_FILE_SIZE] = 0; - entry->line = f->line; + entry->constant = f->constant; + entry->line = f->data.line; entry->correct = val == expect; if (!call_filter_check_discard(call, entry, buffer, event)) @@ -89,7 +90,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect) } static inline -void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) +void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect) { if (!branch_tracing_enabled) return; @@ -195,7 +196,7 @@ core_initcall(init_branch_tracer); #else static inline -void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) +void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect) { } #endif /* CONFIG_BRANCH_TRACER */ @@ -214,7 +215,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, * conditions that the recursive nightmare that exists is too * much to try to get working. At least for now. */ - trace_likely_condition(&f->data, val, expect); + trace_likely_condition(f, val, expect); /* FIXME: Make this atomic! */ if (val == expect) diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index eb7396b7e7c3..c203ac4df791 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -328,11 +328,13 @@ FTRACE_ENTRY(branch, trace_branch, __array( char, func, TRACE_FUNC_SIZE+1 ) __array( char, file, TRACE_FILE_SIZE+1 ) __field( char, correct ) + __field( char, constant ) ), - F_printk("%u:%s:%s (%u)", + F_printk("%u:%s:%s (%u)%s", __entry->line, - __entry->func, __entry->file, __entry->correct), + __entry->func, __entry->file, __entry->correct, + __entry->constant ? " CONSTANT" : ""), FILTER_OTHER ); -- 2.10.2
