Re: [PATCH] trace_syscalls: add missed field

[Lai Jiangshan <laijs@cn.fujitsu.com>]

Frederic Weisbecker wrote:
> On Thu, Nov 26, 2009 at 03:49:33PM +0800, Lai Jiangshan wrote:
>> Field syscall number is missed in syscall_enter_define_fields()/
>> syscall_exit_define_fields().
>>
>> syscall number is also needed for event filter or other users.
>>
>> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
> 
> 


For all kinds of tracer, all fields are "defined"
by trace_define_field(), except this one.
Maybe because I don't like inconsistent codes.

> 
> Well, I don't think it's very useful for in-kernel filtering.
> Filtering a syscall event by its number would mean filtering all
> event for this syscall. This is the same as not tracing it.
> 
> Or do you have other usecases in mind?
> 

Current, only filter use struct ftrace_event_call->fields,
so there is no other usecases ^_^.
But my next take of "tracing: use defined fields to print formats"
will use it.