Ingo,
Li sent a patch that does a cleaner processing of the format file. It
removes a hack that is used to notify the show part of the seqfile
formatting that a newline needs to be used.
Li's solution is cleaner and is better for the release.
Please pull the latest tip/perf/urgent tree, which can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
tip/perf/urgent
Li Zefan (1):
tracing: Clean up seqfile code for format file
----
kernel/trace/trace_events.c | 55 ++++++++++++++-----------------------------
1 files changed, 18 insertions(+), 37 deletions(-)
---------------------------
commit 86397dc3ccfc0e17b7550d05eaf15fe91f6498dd
Author: Li Zefan <lizf@cn.fujitsu.com>
Date: Tue Aug 17 13:53:06 2010 +0800
tracing: Clean up seqfile code for format file
Remove the nasty hack that marks a pointer's LSB to distinguish common
fields from event fields. Replace it with a more sane approach.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4C6A23C2.9020606@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 4c758f1..398c0e8 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -600,21 +600,29 @@ out:
enum {
FORMAT_HEADER = 1,
- FORMAT_PRINTFMT = 2,
+ FORMAT_FIELD_SEPERATOR = 2,
+ FORMAT_PRINTFMT = 3,
};
static void *f_next(struct seq_file *m, void *v, loff_t *pos)
{
struct ftrace_event_call *call = m->private;
struct ftrace_event_field *field;
- struct list_head *head;
+ struct list_head *common_head = &ftrace_common_fields;
+ struct list_head *head = trace_get_fields(call);
(*pos)++;
switch ((unsigned long)v) {
case FORMAT_HEADER:
- head = &ftrace_common_fields;
+ if (unlikely(list_empty(common_head)))
+ return NULL;
+
+ field = list_entry(common_head->prev,
+ struct ftrace_event_field, link);
+ return field;
+ case FORMAT_FIELD_SEPERATOR:
if (unlikely(list_empty(head)))
return NULL;
@@ -626,31 +634,10 @@ static void *f_next(struct seq_file *m, void *v, loff_t *pos)
return NULL;
}
- head = trace_get_fields(call);
-
- /*
- * To separate common fields from event fields, the
- * LSB is set on the first event field. Clear it in case.
- */
- v = (void *)((unsigned long)v & ~1L);
-
field = v;
- /*
- * If this is a common field, and at the end of the list, then
- * continue with main list.
- */
- if (field->link.prev == &ftrace_common_fields) {
- if (unlikely(list_empty(head)))
- return NULL;
- field = list_entry(head->prev, struct ftrace_event_field, link);
- /* Set the LSB to notify f_show to print an extra newline */
- field = (struct ftrace_event_field *)
- ((unsigned long)field | 1);
- return field;
- }
-
- /* If we are done tell f_show to print the format */
- if (field->link.prev == head)
+ if (field->link.prev == common_head)
+ return (void *)FORMAT_FIELD_SEPERATOR;
+ else if (field->link.prev == head)
return (void *)FORMAT_PRINTFMT;
field = list_entry(field->link.prev, struct ftrace_event_field, link);
@@ -688,22 +675,16 @@ static int f_show(struct seq_file *m, void *v)
seq_printf(m, "format:\n");
return 0;
+ case FORMAT_FIELD_SEPERATOR:
+ seq_putc(m, '\n');
+ return 0;
+
case FORMAT_PRINTFMT:
seq_printf(m, "\nprint fmt: %s\n",
call->print_fmt);
return 0;
}
- /*
- * To separate common fields from event fields, the
- * LSB is set on the first event field. Clear it and
- * print a newline if it is set.
- */
- if ((unsigned long)v & 1) {
- seq_putc(m, '\n');
- v = (void *)((unsigned long)v & ~1L);
- }
-
field = v;
/*
--
