Re: [PATCH 1/1] RDMA/rxe: Make pr_fmt work

[Zhu Yanjun <yanjun.zhu@linux.dev>]

在 2024/4/5 1:59, Jason Gunthorpe 写道:
> On Thu, Apr 04, 2024 at 08:03:35PM +0200, Zhu Yanjun wrote:
>>>>> Because this driver will finally call printk function to output the logs,
>>>>> the header file include/linux/printk.h needs be included.
>>>>>
>>>>> In include/linux/printk.h, pr_fmt is defined.
>>>> This doesn't make sense, printk.h has:
>>>>
>>>> #ifndef pr_fmt
>>>> #define pr_fmt(fmt) fmt
>>>> #endif
>>>>
>>>> Before or after printk.h should not have an impact.
>>
>>
>> Sorry. The previous mail is not sent successfully. I resend it.
>>
>>> #ifndef pr_fmt
>>>
>>> ...
>>>
>>> #endif
>>>
>>> The above will not undefine pr_fmt.
>>>
>>> #undef pr_fmt will undefine pr_fmt.
>>>
>>> This link explains the above in details.
>>>
>> https://www.techonthenet.com/c_language/directives/ifndef.php
> 
> Why would you want to undefine it? The point is to #define it to the
> rxe specific value. If it is already set to the rxe specific value
> before including printk.h then it will work fine?

Got your point. There are about more 130 header files that define pr_fmt 
in the kernel include directory. And these header files are included one 
another. Is there any tool to clarify the including relationship between 
these header files?

Thanks a lot
Zhu Yanjun
> 
> Jason