Re: [PATCH 1/2] perf: convert: fix duplicate field names and avoid reserved keywords.

[JÃrÃmie Galarneau]

On Wed, Jan 21, 2015 at 8:38 PM, Wang Nan <wangnan0@xxxxxxxxxx> wrote:
> On 2015/1/21 23:56, JÃrÃmie Galarneau wrote:
>> On Wed, Jan 21, 2015 at 9:11 AM, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>>> On Wed, Jan 21, 2015 at 11:23:54AM +0800, Wang Nan wrote:
>>>> Some parameters of syscall tracepoints named as 'nr', 'event', etc.
>>>> When dealing with them, perf convert to ctf meets some problem:
>>>>
>>>>  1. If a parameter with name 'nr', it will duplicate syscall's
>>>>     common field 'nr'. One such syscall is io_submit().
>>>>
>>>>  2. If a parameter with name 'event', it is denied to be inserted
>>>>     because 'event' is a babeltrace keywork. One such syscall is
>>>>     epoll_ctl.
>>>
>>> hum, so this problem 2 is detectable only via bt_ctf_event_class_add_field function?
>>>
>>> how big is the blaklist?
>>>
>>
>> The blacklist is defined by the CTF specification here [1].
>>
>> JÃrÃmie
>>
>> [1] http://git.efficios.com/?p=ctf.git;a=blob;f=common-trace-format-specification.txt;h=abe4fb70fff7f17f6e8242f313fb74bff44cf89a;hb=HEAD#l1477
>
> Is there any possibility that the someone expand the list?
>

Good question. There is discussion around a v1.9 version of the CTF
spec going on at the moment (which should not affect the Babeltrace
API).

As far as I know, adding "__attribute__" has been discussed. CC'ing
Mathieu Desnoyer who may have other extensions in mind.

JÃrÃmie

>>
>>> SNIP
>>>
>>>> +}
>>>> +
>>>>  static int add_tracepoint_fields_types(struct ctf_writer *cw,
>>>>                                      struct format_field *fields,
>>>>                                      struct bt_ctf_event_class *event_class)
>>>> @@ -577,6 +609,9 @@ static int add_tracepoint_fields_types(struct ctf_writer *cw,
>>>>       for (field = fields; field; field = field->next) {
>>>>               struct bt_ctf_field_type *type;
>>>>               unsigned long flags = field->flags;
>>>> +             struct bt_ctf_field_type *f = NULL;
>>>> +             char *name;
>>>> +             int dup = 1;
>>>>
>>>>               pr2("  field '%s'\n", field->name);
>>>>
>>>> @@ -595,14 +630,36 @@ static int add_tracepoint_fields_types(struct ctf_writer *cw,
>>>>               if (flags & FIELD_IS_ARRAY)
>>>>                       type = bt_ctf_field_type_array_create(type, field->arraylen);
>>>>
>>>> -             ret = bt_ctf_event_class_add_field(event_class, type,
>>>> -                             field->name);
>>>> +             /* Check name duplication */
>>>> +             name = field->name;
>>>
>>> could you please put this in separated function like 'get_field_name(..)'
>>> so we dont polute this function even more
>>>
>>>                 name == get_field_name(...)
>>>                 if (!name)
>>>                         error path
>>>
>>>
>>> thanks,
>>> jirka
>>
>>
>>
>
>



-- 
JÃrÃmie Galarneau
EfficiOS Inc.
http://www.efficios.com
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