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authorSteven Rostedt <srostedt@redhat.com>2009-03-05 21:35:29 -0500
committerSteven Rostedt <srostedt@redhat.com>2009-03-05 21:46:44 -0500
commit770cb24345c0f6e0d47bd2b94aa6d67bea6f8b54 (patch)
treeec76651c686c02249c1455446801cf2b9d823879 /kernel/trace/trace_events.c
parent33b0c229e3abeae00493ed1d6f0b07191977a0a2 (diff)
downloadblackbird-op-linux-770cb24345c0f6e0d47bd2b94aa6d67bea6f8b54.tar.gz
blackbird-op-linux-770cb24345c0f6e0d47bd2b94aa6d67bea6f8b54.zip
tracing: add format files for ftrace default entries
Impact: allow user apps to read binary format of basic ftrace entries Currently, only defined raw events export their formats so a binary reader can parse them. There's no reason that the default ftrace entries can't export their formats. This patch adds a subsystem called "ftrace" in the events directory that includes the ftrace entries for basic ftrace recorded items. These only have three files in the events directory: type : printf available_types : printf format : format for the event entry For example: # cat /debug/tracing/events/ftrace/wakeup/format name: wakeup ID: 3 format: field:unsigned char type; offset:0; size:1; field:unsigned char flags; offset:1; size:1; field:unsigned char preempt_count; offset:2; size:1; field:int pid; offset:4; size:4; field:int tgid; offset:8; size:4; field:unsigned int prev_pid; offset:12; size:4; field:unsigned char prev_prio; offset:16; size:1; field:unsigned char prev_state; offset:17; size:1; field:unsigned int next_pid; offset:20; size:4; field:unsigned char next_prio; offset:24; size:1; field:unsigned char next_state; offset:25; size:1; field:unsigned int next_cpu; offset:28; size:4; print fmt: "%u:%u:%u ==+ %u:%u:%u [%03u]" Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r--kernel/trace/trace_events.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 210e71ff82db..4488d90e75ef 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -656,11 +656,13 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events)
return -1;
}
- entry = debugfs_create_file("enable", 0644, call->dir, call,
- &ftrace_enable_fops);
- if (!entry)
- pr_warning("Could not create debugfs "
- "'%s/enable' entry\n", call->name);
+ if (call->regfunc) {
+ entry = debugfs_create_file("enable", 0644, call->dir, call,
+ &ftrace_enable_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'%s/enable' entry\n", call->name);
+ }
/* Only let type be writable, if we can change it */
entry = debugfs_create_file("type",
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