Re: [PATCH 2/2] mm/page_ref: add tracepoint to track down page reference manipulation

[Joonsoo Kim]

2016-02-18 23:29 GMT+09:00 Steven Rostedt <rostedt@xxxxxxxxxxx>:
> On Mon, 15 Feb 2016 12:04:50 +0900
> js1304@xxxxxxxxx wrote:
>
>
>> diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h
>> index 534249c..fd6d9a5 100644
>> --- a/include/linux/page_ref.h
>> +++ b/include/linux/page_ref.h
>> @@ -1,6 +1,54 @@
>>  #include <linux/atomic.h>
>>  #include <linux/mm_types.h>
>>  #include <linux/page-flags.h>
>> +#include <linux/tracepoint-defs.h>
>> +
>> +extern struct tracepoint __tracepoint_page_ref_set;
>> +extern struct tracepoint __tracepoint_page_ref_mod;
>> +extern struct tracepoint __tracepoint_page_ref_mod_and_test;
>> +extern struct tracepoint __tracepoint_page_ref_mod_and_return;
>> +extern struct tracepoint __tracepoint_page_ref_mod_unless;
>> +extern struct tracepoint __tracepoint_page_ref_freeze;
>> +extern struct tracepoint __tracepoint_page_ref_unfreeze;
>> +
>> +#ifdef CONFIG_DEBUG_PAGE_REF
>
> Please add a comment here. Something to the effect of:

Okay!

> /*
>  * Ideally we would want to use the trace_<tracepoint>_enabled() helper
>  * functions. But due to include header file issues, that is not
>  * feasible. Instead we have to open code the static key functions.
>  *
>  * See trace_##name##_enabled(void) in include/linux/tracepoint.h
>  */
>
> I may have to work on something that lets these helpers be defined in
> headers. I have some ideas on how to do that. But for now, this
> solution is fine.

Okay.

Thanks.