From 6c77221df96177da0520847ce91e33f539fb8b2d Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Tue, 30 Jul 2019 22:08:50 +0800 Subject: [PATCH] fgraph: Remove redundant ftrace_graph_notrace_addr() test We already have tested it before. The second one should be removed. With this change, the performance should have little improvement. Link: http://lkml.kernel.org/r/20190730140850.7927-1-changbin.du@gmail.com Cc: stable@vger.kernel.org Fixes: 9cd2992f2d6c ("fgraph: Have set_graph_notrace only affect function_graph tracer") Signed-off-by: Changbin Du Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_functions_graph.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 69ebf3c2f1b5..78af97163147 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -137,6 +137,13 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) return 0; + /* + * Do not trace a function if it's filtered by set_graph_notrace. + * Make the index of ret stack negative to indicate that it should + * ignore further functions. But it needs its own ret stack entry + * to recover the original index in order to continue tracing after + * returning from the function. + */ if (ftrace_graph_notrace_addr(trace->func)) { trace_recursion_set(TRACE_GRAPH_NOTRACE_BIT); /* @@ -155,16 +162,6 @@ int trace_graph_entry(struct ftrace_graph_ent *trace) if (ftrace_graph_ignore_irqs()) return 0; - /* - * Do not trace a function if it's filtered by set_graph_notrace. - * Make the index of ret stack negative to indicate that it should - * ignore further functions. But it needs its own ret stack entry - * to recover the original index in order to continue tracing after - * returning from the function. - */ - if (ftrace_graph_notrace_addr(trace->func)) - return 1; - /* * Stop here if tracing_threshold is set. We only write function return * events to the ring buffer.