From c4a8e8be2d43cc22b371e8e9c05c253409759d94 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 2 Feb 2009 20:29:21 -0200 Subject: trace: better manage the context info for events Impact: make trace_event more convenient for tracers All tracers (for the moment) that use the struct trace_event want to have the context info printed before their own output: the pid/cmdline, cpu, and timestamp. But some other tracers that want to implement their trace_event callbacks will not necessary need these information or they may want to format them as they want. This patch adds a new default-enabled trace option: TRACE_ITER_CONTEXT_INFO When disabled through: echo nocontext-info > /debugfs/tracing/trace_options The pid, cpu and timestamps headers will not be printed. IE with the sched_switch tracer with context-info (default): bash-2935 [001] 100.356561: 2935:120:S ==> [001] 0:140:R -0 [000] 100.412804: 0:140:R + [000] 11:115:S events/0 -0 [000] 100.412816: 0:140:R ==> [000] 11:115:R events/0 events/0-11 [000] 100.412829: 11:115:S ==> [000] 0:140:R Without context-info: 2935:120:S ==> [001] 0:140:R 0:140:R + [000] 11:115:S events/0 0:140:R ==> [000] 11:115:R events/0 11:115:S ==> [000] 0:140:R A tracer can disable it at runtime by clearing the bit TRACE_ITER_CONTEXT_INFO in trace_flags. The print routines were renamed to trace_print_context and trace_print_lat_context, so that they can be used by tracers if they want to use them for one of the trace_event callbacks. Signed-off-by: Frederic Weisbecker Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Ingo Molnar --- kernel/trace/trace_output.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel/trace/trace_output.h') diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h index 1cbab5e3dc99..ec2ed90f10f0 100644 --- a/kernel/trace/trace_output.h +++ b/kernel/trace/trace_output.h @@ -33,6 +33,9 @@ int seq_print_userip_objs(const struct userstack_entry *entry, int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm, unsigned long ip, unsigned long sym_flags); +int trace_print_context(struct trace_iterator *iter); +int trace_print_lat_context(struct trace_iterator *iter); + struct trace_event *ftrace_find_event(int type); int register_ftrace_event(struct trace_event *event); int unregister_ftrace_event(struct trace_event *event); -- cgit v1.2.3