Messages in this thread | | | Date | Tue, 15 Dec 2009 15:39:10 +0800 | From | Lai Jiangshan <> | Subject | [PATCH V5 0/10] tracing: use defined fields to print formats |
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It seems that ftrace_format_##call() and ftrace_define_fields_##call() are duplicate more or less.
trace_define_field() defines fields and links them into strcut ftrace_event_call. We reuse them to print formats and remove ftrace_format_##call(). It make all things simpler.
Quote(From Steven): """ I totally agree that your patch is a nice clean up, and saves space and prevents more bugs. On the other hand, we are changing an API to users where all tools that parse this must be able to cope. """
But now, this new patchset does not change any API to userspace. PATCH#1 fix a mistake of trace_kprobe's format. You can
1) apply PATCH#1, compile, reboot with new kernel, add kprobe_events, save all the format files.
2) apply PATCH#2...10 additionally, compile, reboot with new kernel, add kprobe_events, save all the format files.
Take diffs of these two sets of format files, there are nothing changed.
So, this patchset does not change any API.
And this patchset does a nice cleanup and removes hunk of codes: # size vmlinux.o.old vmlinux.o text data bss dec hex filename 5640127 589938 1299464 7529529 72e439 vmlinux.o.old 5620506 589938 1298888 7509332 729554 vmlinux.o
Patches are partitioned for easy to review: PATCH#1~5 prepare (PATCH#2 fix a regression) PATCH#6 add "print_fmt" field to struct ftrace_event_call and and initialization code for it. PATCH#7 "print_fmt" initialization code for trace_syscalls PATCH#8 "print_fmt" initialization code for trace_kprobe PATCH#9 use defined fields and "print_fmt" to print formats PATCH#10 remove show_format and corresponding codes.
How this patchset works:
# cat events/irq/irq_handler_entry/format name: irq_handler_entry ID: 97 format:
A) ======> name, ID, and a string "format:"
field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:int common_lock_depth; offset:8; size:4; signed:1;
field:int irq; offset:12; size:4; signed:1; field:__data_loc char[] name; offset:16; size:4; signed:1;
B) ========> fields.
print fmt: "irq=%d name=%s", REC->irq, __get_str(name)
C) ========> string "print fmt: " and the print format after it.
For B) Ensure all fields are add into struct ftrace_event_call->fields. (patch#4) Ensure all fields are correct. (patch#5)
For C) add a print_fmt field (patch#6) init print_fmt carefully (patch#6 and patch#7 patch#8)
So when we generate format file: print name print ID print string "format:" use struct ftrace_event_call->fields to print fields use struct ftrace_event_call->print_fmt to print "print fmt: XXXXXXXXXXX"
-- Lai
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- include/linux/ftrace_event.h | 3 include/linux/syscalls.h | 8 -- include/trace/ftrace.h | 168 +++++++++--------------------------------- include/trace/syscall.h | 4 - kernel/trace/trace_events.c | 78 ++++++++++--------- kernel/trace/trace_export.c | 94 ++++------------------- kernel/trace/trace_kprobe.c | 103 +++++++++++-------------- kernel/trace/trace_syscalls.c | 96 ++++++++++++------------ 8 files changed, 192 insertions(+), 362 deletions(-)
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