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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-03-19 20:26:13 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-20 10:17:05 +0100 |
| commit | 23725aeeab10ba02bcf10ec49ad73146b54cb52f (patch) | |
| tree | 02d5932639e8d76be42a057d8d6ff73026949d12 /kernel | |
| parent | 44fc6ee92356aa3be31798ced220ab5abd898781 (diff) | |
| download | linux-23725aeeab10ba02bcf10ec49ad73146b54cb52f.tar.gz linux-23725aeeab10ba02bcf10ec49ad73146b54cb52f.tar.bz2 linux-23725aeeab10ba02bcf10ec49ad73146b54cb52f.zip | |
ftrace: provide an id file for each event
Since not every event has a format file to read the id from,
expose it explicitly in a separate file.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20090319194233.372534033@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_events.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index c88227b3b9db..7763db8fd0b3 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -412,6 +412,29 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt, return r; } +static ssize_t +event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) +{ + struct ftrace_event_call *call = filp->private_data; + struct trace_seq *s; + int r; + + if (*ppos) + return 0; + + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + trace_seq_init(s); + trace_seq_printf(s, "%d\n", call->id); + + r = simple_read_from_buffer(ubuf, cnt, ppos, + s->buffer, s->len); + kfree(s); + return r; +} + static const struct seq_operations show_event_seq_ops = { .start = t_start, .next = t_next, @@ -452,6 +475,11 @@ static const struct file_operations ftrace_event_format_fops = { .read = event_format_read, }; +static const struct file_operations ftrace_event_id_fops = { + .open = tracing_open_generic, + .read = event_id_read, +}; + static struct dentry *event_trace_events_dir(void) { static struct dentry *d_tracer; @@ -550,6 +578,14 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events) "'%s/enable' entry\n", call->name); } + if (call->id) { + entry = debugfs_create_file("id", 0444, call->dir, call, + &ftrace_event_id_fops); + if (!entry) + pr_warning("Could not create debugfs '%s/id' entry\n", + call->name); + } + /* A trace may not want to export its format */ if (!call->show_format) return 0; |