lkml.org 
[lkml]   [2009]   [Apr]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[RFC][PATCH] tracing: Make branch trace display correct header
Before patch:
# tracer: branch
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
<...>-2981 [000] 24008.872738: [ ok ] trace_irq_handler_exit:irq_event_types.h:41
<...>-2981 [000] 24008.872742: [ ok ] note_interrupt:spurious.c:229
...

After patch:
# tracer: branch
#
# TASK-PID CPU# TIMESTAMP CORRECT FUNC:FILE:LINE
# | | | | | |
<...>-2985 [000] 26329.142970: [ ok ] slab_free:slub.c:1776
<...>-2985 [000] 26329.142972: [ ok ] trace_kmem_cache_free:kmem_event_types.h:191
...

But it is not the best fix way.
When format(length) of TASK-PID, CPU and TIMESTAMP chanegd in trace.c,
other files who uses there fields need to changed for print right header line.

Maybe we can make a function to print header line of these 3 field:
print_common_head()
{
seq_puts(s, "# TASK-PID CPU# TIMESTAMP");
}

and call this function in other files' print_header:
static void branch_print_header(struct seq_file *s)
{
print_common_head();
seq_puts(s, " CORRECT FUNC:FILE:LINE\n");
}

But if header line is multi-line, this way can't work.

Another way is to export specific header-line content in other files:
static void branch_print_header(char *buf, int len)
{
strcpy(buf, " CORRECT FUNC:FILE:LINE\n"
" | |\n"
);
}
And combile common-header and specific header in trace.c, then do seq_puts.
But this seems too complex for tracing framework.

Similar problem exists in other tracers as sched_switch.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
---
kernel/trace/trace_branch.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 8e64e60..7a7a9fd 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -157,6 +157,13 @@ static enum print_line_t trace_branch_print(struct trace_iterator *iter,
return TRACE_TYPE_HANDLED;
}

+static void branch_print_header(struct seq_file *s)
+{
+ seq_puts(s, "# TASK-PID CPU# TIMESTAMP CORRECT"
+ " FUNC:FILE:LINE\n");
+ seq_puts(s, "# | | | | | "
+ " |\n");
+}

static struct trace_event trace_branch_event = {
.type = TRACE_BRANCH,
@@ -171,6 +178,7 @@ static struct tracer branch_trace __read_mostly =
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_branch,
#endif /* CONFIG_FTRACE_SELFTEST */
+ .print_header = branch_print_header,
};

__init static int init_branch_tracer(void)
-- 1.5.5.3


\
 
 \ /
  Last update: 2009-04-13 10:05    [W:0.072 / U:0.212 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site