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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2010-01-13 19:38:30 +0800 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2010-01-29 01:05:12 +0100 |
| commit | ea2c68a08fedb5053ba312d661e47df9f4d72411 (patch) | |
| tree | 76e5e61b8377aac6283670481171bf899905052b /kernel/trace/trace_functions_graph.c | |
| parent | 24a53652e361321b09df5040711e69387344ce09 (diff) | |
| download | kernel_samsung_smdk4412-ea2c68a08fedb5053ba312d661e47df9f4d72411.zip kernel_samsung_smdk4412-ea2c68a08fedb5053ba312d661e47df9f4d72411.tar.gz kernel_samsung_smdk4412-ea2c68a08fedb5053ba312d661e47df9f4d72411.tar.bz2 | |
tracing: Simplify test for function_graph tracing start point
In the function graph tracer, a calling function is to be traced
only when it is enabled through the set_graph_function file,
or when it is nested in an enabled function.
Current code uses TSK_TRACE_FL_GRAPH to test whether it is nested
or not. Looking at the code, we can get this:
(trace->depth > 0) <==> (TSK_TRACE_FL_GRAPH is set)
trace->depth is more explicit to tell that it is nested.
So we use trace->depth directly and simplify the code.
No functionality is changed.
TSK_TRACE_FL_GRAPH is not removed yet, it is left for future usage.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4B4DB0B6.7040607@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index f225229..616b135 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -215,7 +215,8 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) if (!ftrace_trace_task(current)) return 0; - if (!ftrace_graph_addr(trace->func)) + /* trace it when it is-nested-in or is a function enabled. */ + if (!(trace->depth || ftrace_graph_addr(trace->func))) return 0; local_irq_save(flags); @@ -228,9 +229,6 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) } else { ret = 0; } - /* Only do the atomic if it is not already set */ - if (!test_tsk_trace_graph(current)) - set_tsk_trace_graph(current); atomic_dec(&data->disabled); local_irq_restore(flags); @@ -278,8 +276,6 @@ void trace_graph_return(struct ftrace_graph_ret *trace) pc = preempt_count(); __trace_graph_return(tr, trace, flags, pc); } - if (!trace->depth) - clear_tsk_trace_graph(current); atomic_dec(&data->disabled); local_irq_restore(flags); } |