From 8861dd303cba879bae9a9dcee74042fb642bf03b Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Wed, 31 Aug 2016 11:55:29 +0900 Subject: [PATCH] ftrace: Access ret_stack->subtime only in the function profiler The subtime is used only for function profiler with function graph tracer enabled. Move the definition of subtime under CONFIG_FUNCTION_PROFILER to reduce the memory usage. Also move the initialization of subtime into the graph entry callback. Link: http://lkml.kernel.org/r/20160831025529.24018-1-namhyung@kernel.org Cc: Ingo Molnar Cc: Josh Poimboeuf Signed-off-by: Namhyung Kim Signed-off-by: Steven Rostedt --- Documentation/trace/ftrace.txt | 10 +++++----- include/linux/ftrace.h | 2 ++ kernel/trace/ftrace.c | 6 ++++++ kernel/trace/trace_functions_graph.c | 1 - 4 files changed, 13 insertions(+), 6 deletions(-) diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index a6b3705e62a6..185c39fea2a0 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -858,11 +858,11 @@ x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6] When enabled, it will account time the task has been scheduled out as part of the function call. - graph-time - When running function graph tracer, to include the - time to call nested functions. When this is not set, - the time reported for the function will only include - the time the function itself executed for, not the time - for functions that it called. + graph-time - When running function profiler with function graph tracer, + to include the time to call nested functions. When this is + not set, the time reported for the function will only + include the time the function itself executed for, not the + time for functions that it called. record-cmd - When any event or tracer is enabled, a hook is enabled in the sched_switch trace point to fill comm cache diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 7d565afe35d2..1e2b316d6693 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -794,7 +794,9 @@ struct ftrace_ret_stack { unsigned long ret; unsigned long func; unsigned long long calltime; +#ifdef CONFIG_FUNCTION_PROFILER unsigned long long subtime; +#endif unsigned long fp; }; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 84752c8e28b5..2050a7652a86 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -872,7 +872,13 @@ function_profile_call(unsigned long ip, unsigned long parent_ip, #ifdef CONFIG_FUNCTION_GRAPH_TRACER static int profile_graph_entry(struct ftrace_graph_ent *trace) { + int index = trace->depth; + function_profile_call(trace->func, 0, NULL, NULL); + + if (index >= 0 && index < FTRACE_RETFUNC_DEPTH) + current->ret_stack[index].subtime = 0; + return 1; } diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index e14017c36170..148c90f1e49b 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -170,7 +170,6 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, current->ret_stack[index].ret = ret; current->ret_stack[index].func = func; current->ret_stack[index].calltime = calltime; - current->ret_stack[index].subtime = 0; current->ret_stack[index].fp = frame_pointer; *depth = current->curr_ret_stack;